WorldWideScience

Sample records for rendered virtual viewpoint

  1. Image Based Rendering and Virtual Reality

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation.......The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation....

  2. Image Based Rendering and Virtual Reality

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation.......The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation....

  3. Joint Rendering and Segmentation of Free-Viewpoint Video

    Directory of Open Access Journals (Sweden)

    Ishii Masato

    2010-01-01

    Full Text Available Abstract This paper presents a method that jointly performs synthesis and object segmentation of free-viewpoint video using multiview video as the input. This method is designed to achieve robust segmentation from online video input without per-frame user interaction and precomputations. This method shares a calculation process between the synthesis and segmentation steps; the matching costs calculated through the synthesis step are adaptively fused with other cues depending on the reliability in the segmentation step. Since the segmentation is performed for arbitrary viewpoints directly, the extracted object can be superimposed onto another 3D scene with geometric consistency. We can observe that the object and new background move naturally along with the viewpoint change as if they existed together in the same space. In the experiments, our method can process online video input captured by a 25-camera array and show the result image at 4.55 fps.

  4. Rendering of 3D Dynamic Virtual Environments

    CERN Document Server

    Catanese, Salvatore; Fiumara, Giacomo; Pagano, Francesco

    2011-01-01

    In this paper we present a framework for the rendering of dynamic 3D virtual environments which can be integrated in the development of videogames. It includes methods to manage sounds and particle effects, paged static geometries, the support of a physics engine and various input systems. It has been designed with a modular structure to allow future expansions. We exploited some open-source state-of-the-art components such as OGRE, PhysX, ParticleUniverse, etc.; all of them have been properly integrated to obtain peculiar physical and environmental effects. The stand-alone version of the application is fully compatible with Direct3D and OpenGL APIs and adopts OpenAL APIs to manage audio cards. Concluding, we devised a showcase demo which reproduces a dynamic 3D environment, including some particular effects: the alternation of day and night infuencing the lighting of the scene, the rendering of terrain, water and vegetation, the reproduction of sounds and atmospheric agents.

  5. Viewpoint Selection Using Hybrid Simplex Search and Particle Swarm Optimization for Volume Rendering

    Directory of Open Access Journals (Sweden)

    Zhang You-sai,,,

    2012-09-01

    Full Text Available In this paper we proposed a novel method of viewpoint selection using the hybrid Nelder-Mead (NM simplex search and particle swarm optimization (PSO to improve the efficiency and the intelligent level of volume rendering. This method constructed the viewpoint quality evaluation function in the form of entropy by utilizing the luminance and structure features of the two-dimensional projective image of volume data. During the process of volume rendering, the hybrid NM-PSO algorithm intended to locate the globally optimal viewpoint or a set of the optimized viewpoints automatically and intelligently. Experimental results have shown that this method avoids redundant interactions and evidently improves the efficiency of volume rendering. The optimized viewpoints can focus on the important structural features or the region of interest in volume data and exhibit definite correlation with the perception character of human visual system. Compared with the methods based on PSO or NM simplex search, our method has the better performance of convergence rate, convergence accuracy and robustness.

  6. Virtual Environment of Real Sport Hall and Analyzing Rendering Quality

    Directory of Open Access Journals (Sweden)

    Filip Popovski

    2015-02-01

    Full Text Available Here is presented virtual environment of a real sport hall created in Quest3D VR Edition. All analyzes of the rendering quality, techniques of interaction and performance of the system in real time are presented. We made critical analysis on all of these techniques on different machines and have excellent results.

  7. Virtual try-on through image-based rendering.

    Science.gov (United States)

    Hauswiesner, Stefan; Straka, Matthias; Reitmayr, Gerhard

    2013-09-01

    Virtual try-on applications have become popular because they allow users to watch themselves wearing different clothes without the effort of changing them physically. This helps users to make quick buying decisions and, thus, improves the sales efficiency of retailers. Previous solutions usually involve motion capture, 3D reconstruction or modeling, which are time consuming and not robust for all body poses. Our method avoids these steps by combining image-based renderings of the user and previously recorded garments. It transfers the appearance of a garment recorded from one user to another by matching input and recorded frames, image-based visual hull rendering, and online registration methods. Using images of real garments allows for a realistic rendering quality with high performance. It is suitable for a wide range of clothes and complex appearances, allows arbitrary viewing angles, and requires only little manual input. Our system is particularly useful for virtual try-on applications as well as interactive games.

  8. Binaural technology for e.g. rendering auditory virtual environments

    DEFF Research Database (Denmark)

    Hammershøi, Dorte

    2008-01-01

    , helped mediate the understanding that if the transfer functions could be mastered, then important dimensions of the auditory percept could also be controlled. He early understood the potential of using the HRTFs and numerical sound transmission analysis programs for rendering auditory virtual...... environments. Jens Blauert participated in many European cooperation projects exploring  this field (and others), among other the SCATIS project addressing the auditory-tactile dimensions in the absence of visual information....

  9. Fast Rendering of Realistic Virtual Character in Game Scene

    Directory of Open Access Journals (Sweden)

    Mengzhao Yang

    2013-07-01

    Full Text Available Human skin is made up of multiple translucent layers and rendering of skin appearance usually acquire complex modeling and massive calculation. In some practical applications such as 3D game development, we not only approximate the realistic looking skin but also develop efficient method to implement easily for meeting needs of real-time rendering. In this study, we solve the problem of wrap lighting and introduce a surface details approximation method to give realistic rendering of virtual character. Our method considers that different thicknesses of geometry on the skin surface can result in different scattering degree of incident light and so pre-calculate the diffuse falloff into a look-up texture. Also, we notice that scattering is strongly color dependent and small bumps are common on the skin surface and so pre-soften the finer details on the skin surface according to the R/G/B channel. At last, we linearly interpolate the diffuse lighting with different scattering degree from the look-up texture sampled with the curvature and NdotL. Experiment results show that the proposed approach yields realistic virtual character and obtains high frames per second in real-time rendering.

  10. High dynamic range (HDR) virtual bronchoscopy rendering for video tracking

    Science.gov (United States)

    Popa, Teo; Choi, Jae

    2007-03-01

    In this paper, we present the design and implementation of a new rendering method based on high dynamic range (HDR) lighting and exposure control. This rendering method is applied to create video images for a 3D virtual bronchoscopy system. One of the main optical parameters of a bronchoscope's camera is the sensor exposure. The exposure adjustment is needed since the dynamic range of most digital video cameras is narrower than the high dynamic range of real scenes. The dynamic range of a camera is defined as the ratio of the brightest point of an image to the darkest point of the same image where details are present. In a video camera exposure is controlled by shutter speed and the lens aperture. To create the virtual bronchoscopic images, we first rendered a raw image in absolute units (luminance); then, we simulated exposure by mapping the computed values to the values appropriate for video-acquired images using a tone mapping operator. We generated several images with HDR and others with low dynamic range (LDR), and then compared their quality by applying them to a 2D/3D video-based tracking system. We conclude that images with HDR are closer to real bronchoscopy images than those with LDR, and thus, that HDR lighting can improve the accuracy of image-based tracking.

  11. Realistic Haptic Rendering of Interacting Deformable Objects in Virtual Environments

    CERN Document Server

    Duriez, Christian; Kheddar, Abderrahmane; Andriot, Claude

    2008-01-01

    A new computer haptics algorithm to be used in general interactive manipulations of deformable virtual objects is presented. In multimodal interactive simulations, haptic feedback computation often comes from contact forces. Subsequently, the fidelity of haptic rendering depends significantly on contact space modeling. Contact and friction laws between deformable models are often simplified in up to date methods. They do not allow a "realistic" rendering of the subtleties of contact space physical phenomena (such as slip and stick effects due to friction or mechanical coupling between contacts). In this paper, we use Signorini's contact law and Coulomb's friction law as a computer haptics basis. Real-time performance is made possible thanks to a linearization of the behavior in the contact space, formulated as the so-called Delassus operator, and iteratively solved by a Gauss-Seidel type algorithm. Dynamic deformation uses corotational global formulation to obtain the Delassus operator in which the mass and s...

  12. Reference frames in virtual spatial navigation are viewpoint dependent

    Directory of Open Access Journals (Sweden)

    Ágoston eTörök

    2014-09-01

    Full Text Available Spatial navigation in the mammalian brain relies on a cognitive map of the environment. Such cognitive maps enable us, for example, to take the optimal route from a given location to a known target. The formation of these maps is naturally influenced by our perception of the environment, meaning it is dependent on factors such as our viewpoint and choice of reference frame. Yet, it is unknown how these factors influence the construction of cognitive maps. Here, we evaluated how various combinations of viewpoints and reference frames affect subjects’ performance when they navigated in a bounded virtual environment without landmarks. We measured both their path length and time efficiency and found that (i ground perspective was associated with egocentric frame of reference, (ii aerial perspective was associated with allocentric frame of reference, (iii there was no appreciable performance difference between first and third person egocentric viewing positions and (iv while none of these effects were dependent on gender, males tended to perform better in general. Our study provides evidence that there are inherent associations between visual perspectives and cognitive reference frames. This result has implications about the mechanisms of path integration in the human brain and may also inspire designs of virtual reality applications. Lastly, we demonstrated the effective use of a tablet PC and spatial navigation tasks for studying spatial and cognitive aspects of human memory.

  13. Technologies Render Views of Earth for Virtual Navigation

    Science.gov (United States)

    2012-01-01

    On a December night in 1995, 159 passengers and crewmembers died when American Airlines Flight 965 flew into the side of a mountain while in route to Cali, Colombia. A key factor in the tragedy: The pilots had lost situational awareness in the dark, unfamiliar terrain. They had no idea the plane was approaching a mountain until the ground proximity warning system sounded an alarm only seconds before impact. The accident was of the kind most common at the time CFIT, or controlled flight into terrain says Trey Arthur, research aerospace engineer in the Crew Systems and Aviation Operations Branch at NASA s Langley Research Center. In situations such as bad weather, fog, or nighttime flights, pilots would rely on airspeed, altitude, and other readings to get an accurate sense of location. Miscalculations and rapidly changing conditions could contribute to a fully functioning, in-control airplane flying into the ground. To improve aviation safety by enhancing pilots situational awareness even in poor visibility, NASA began exploring the possibilities of synthetic vision creating a graphical display of the outside terrain on a screen inside the cockpit. How do you display a mountain in the cockpit? You have to have a graphics-powered computer, a terrain database you can render, and an accurate navigation solution, says Arthur. In the mid-1990s, developing GPS technology offered a means for determining an aircraft s position in space with high accuracy, Arthur explains. As the necessary technologies to enable synthetic vision emerged, NASA turned to an industry partner to develop the terrain graphical engine and database for creating the virtual rendering of the outside environment.

  14. Age, Health and Attractiveness Perception of Virtual (Rendered) Human Hair.

    Science.gov (United States)

    Fink, Bernhard; Hufschmidt, Carla; Hirn, Thomas; Will, Susanne; McKelvey, Graham; Lankhof, John

    2016-01-01

    The social significance of physical appearance and beauty has been documented in many studies. It is known that even subtle manipulations of facial morphology and skin condition can alter people's perception of a person's age, health and attractiveness. While the variation in facial morphology and skin condition cues has been studied quite extensively, comparably little is known on the effect of hair on social perception. This has been partly caused by the technical difficulty of creating appropriate stimuli for investigations of people's response to systematic variation of certain hair characteristics, such as color and style, while keeping other features constant. Here, we present a modeling approach to the investigation of human hair perception using computer-generated, virtual (rendered) human hair. In three experiments, we manipulated hair diameter (Experiment 1), hair density (Experiment 2), and hair style (Experiment 3) of human (female) head hair and studied perceptions of age, health and attractiveness. Our results show that even subtle changes in these features have an impact on hair perception. We discuss our findings with reference to previous studies on condition-dependent quality cues in women that influence human social perception, thereby suggesting that hair is a salient feature of human physical appearance, which contributes to the perception of beauty.

  15. Age, Health and Attractiveness Perception of Virtual (Rendered) Human Hair

    Science.gov (United States)

    Fink, Bernhard; Hufschmidt, Carla; Hirn, Thomas; Will, Susanne; McKelvey, Graham; Lankhof, John

    2016-01-01

    The social significance of physical appearance and beauty has been documented in many studies. It is known that even subtle manipulations of facial morphology and skin condition can alter people’s perception of a person’s age, health and attractiveness. While the variation in facial morphology and skin condition cues has been studied quite extensively, comparably little is known on the effect of hair on social perception. This has been partly caused by the technical difficulty of creating appropriate stimuli for investigations of people’s response to systematic variation of certain hair characteristics, such as color and style, while keeping other features constant. Here, we present a modeling approach to the investigation of human hair perception using computer-generated, virtual (rendered) human hair. In three experiments, we manipulated hair diameter (Experiment 1), hair density (Experiment 2), and hair style (Experiment 3) of human (female) head hair and studied perceptions of age, health and attractiveness. Our results show that even subtle changes in these features have an impact on hair perception. We discuss our findings with reference to previous studies on condition-dependent quality cues in women that influence human social perception, thereby suggesting that hair is a salient feature of human physical appearance, which contributes to the perception of beauty. PMID:28066276

  16. On-line Free-viewpoint Video: From Single to Multiple View Rendering

    Institute of Scientific and Technical Information of China (English)

    Vincent Nozick; Hideo Saito

    2008-01-01

    In recent years, many image-based rendering techniques have advanced from static to dynamic scenes and thus become video-based rendering (VBR) methods. But actually, only a few of them can render new views on-line. We present a new VBR system that creates new views of a live dynamic scene. This system provides high quality images and does not require any background subtraction. Our method follows a plane-sweep approach and reaches real-time rendering using consumer graphic hardware, graphics processing unit (GPU). Only one computer is used for both acquisition and rendering. The video stream acquisition is performed by at least 3 webcams. We propose an additional video stream management that extends the number of webcams to 10 or more. These considerations make our system low-cost and hence accessible for everyone. We also present an adaptation of our plane-sweep method to create simultaneously multiple views of the scene in real-time. Our system is especially designed for stereovision using autostereoscopic displays. The new views are computed from 4 webcams connected to a computer and are compressed in order to be transfered to a mobile phone. Using CPU programming, our method provides up to 16 images of the scene in real-time. The use of both GPU and CPU makes this method work on only one consumer grade computer.

  17. Viewpoint

    African Journals Online (AJOL)

    This paper mainly draws on the empirical level of critical realism. The viewpoint ..... General System Theory: Foundations Development Applications. ... In Leal Filho, W. (Ed.), Sustainability and University Life (2nd Ed.) Frankfurt: Peter Lang. pp.

  18. Tactile display for virtual 3D shape rendering

    CERN Document Server

    Mansutti, Alessandro; Bordegoni, Monica; Cugini, Umberto

    2017-01-01

    This book describes a novel system for the simultaneous visual and tactile rendering of product shapes which allows designers to simultaneously touch and see new product shapes during the conceptual phase of product development. This system offers important advantages, including potential cost and time savings, compared with the standard product design process in which digital 3D models and physical prototypes are often repeatedly modified until an optimal design is achieved. The system consists of a tactile display that is able to represent, within a real environment, the shape of a product. Designers can explore the rendered surface by touching curves lying on the product shape, selecting those curves that can be considered style features and evaluating their aesthetic quality. In order to physically represent these selected curves, a flexible surface is modeled by means of servo-actuated modules controlling a physical deforming strip. The tactile display is designed so as to be portable, low cost, modular,...

  19. Perceptive visual attention model based on depth information for free viewpoint video rendering

    Science.gov (United States)

    Park, Min-Chul; Son, Jung-Young

    2009-05-01

    How to detect meaningful video representation becomes an interesting problem in various research communities. Visual attention system detects "Region of Interesting" from input video sequence. Generally the attended regions correspond to visually prominent object in the image in video sequence. In this paper, we have improved previous approaches using spatiotemporal attention modules. We proposed to make use of 3D depth map information in addition to spatiotemporal features. Therefore, the proposed method can compensate typical spatiotemporal saliency approaches for their inaccuracy. Motion is important cue when we derive temporal saliency. On the other hand noise information that deteriorates accuracy of temporal saliency is also obtained during the computation. To obtain the saliency map with more accuracy the noise should be removed. In order to settle down the problem, we used the result of psychological studies on "double opponent receptive field" and "noise filtration" in Middle Temporal area. We also applied "FlagMap" on each frame to prevent "Flickering" of global-area noise. As a result of this consideration, our system can detect the salient regions in the image with higher accuracy while removing noise effectively. It has been applied to several image sequences as a result the proposed method can describe the salient regions with more accuracy in another higher domain than the typical approach does. The obtained result can be applied to generate a spontaneous viewpoint offered by the system itself for "3-D imaging projector" or 3-DTV.

  20. Comparative analysis of video processing and 3D rendering for cloud video games using different virtualization technologies

    Science.gov (United States)

    Bada, Adedayo; Alcaraz-Calero, Jose M.; Wang, Qi; Grecos, Christos

    2014-05-01

    This paper describes a comprehensive empirical performance evaluation of 3D video processing employing the physical/virtual architecture implemented in a cloud environment. Different virtualization technologies, virtual video cards and various 3D benchmarks tools have been utilized in order to analyse the optimal performance in the context of 3D online gaming applications. This study highlights 3D video rendering performance under each type of hypervisors, and other factors including network I/O, disk I/O and memory usage. Comparisons of these factors under well-known virtual display technologies such as VNC, Spice and Virtual 3D adaptors reveal the strengths and weaknesses of the various hypervisors with respect to 3D video rendering and streaming.

  1. Effect of avatars and viewpoints on performance in virtual world: efficiency vs. telepresence

    Directory of Open Access Journals (Sweden)

    Y. Rybarczyk

    2014-10-01

    Full Text Available An increasing number of our interactions are mediated through e-technologies. In order to enhance the human’s feeling of presence into these virtual environments, also known as telepresence, the individual is usually embodied into an avatar. The natural adaptation capabilities, underlain by the plasticity of the body schema, of the human being make a body ownership of the avatar possible, in which the user feels more like his/her virtual alter ego than himself/herself. However, this phenomenon only occurs under specific conditions. Two experiments are designed to study the human’s feeling and performance according to a scale of natural relationship between the participant and the avatar. In both experiments, the human-avatar interaction is carried out by a Natural User Interface (NUI and the individual’s performance is assessed through a behavioural index, based on the concept of affordances, and a questionnaire of presence The first experiment shows that the feeling of telepresence and ownership seem to be greater when the avatar’s kinematics and proportions are close to those of the user. However, the efficiency to complete the task is higher for a more mechanical and stereotypical avatar. The second experiment shows that the manipulation of the viewpoint induces a similar difference across the sessions. Results are discussed in terms of the neurobehavioral processes underlying performance in virtual worlds, which seem to be based on ownership when the virtual artefact ensures a preservation of sensorimotor contingencies, and simple geometrical mapping when the conditions become more artificial.

  2. Virtual reality system for treatment of the fear of public speaking using image-based rendering and moving pictures.

    Science.gov (United States)

    Lee, Jae M; Ku, Jeong H; Jang, Dong P; Kim, Dong H; Choi, Young H; Kim, In Y; Kim, Sun I

    2002-06-01

    The fear of speaking is often cited as the world's most common social phobia. The rapid growth of computer technology enabled us to use virtual reality (VR) for the treatment of the fear of public speaking. There have been two techniques used to construct a virtual environment for the treatment of the fear of public speaking: model-based and movie-based. Virtual audiences and virtual environments made by model-based technique are unrealistic and unnatural. The movie-based technique has a disadvantage in that each virtual audience cannot be controlled respectively, because all virtual audiences are included in one moving picture file. To address this disadvantage, this paper presents a virtual environment made by using image-based rendering (IBR) and chroma keying simultaneously. IBR enables us to make the virtual environment realistic because the images are stitched panoramically with the photos taken from a digital camera. And the use of chroma keying allows a virtual audience to be controlled individually. In addition, a real-time capture technique was applied in constructing the virtual environment to give the subjects more interaction, in that they can talk with a therapist or another subject.

  3. A Virtual Reality System for PTCD Simulation Using Direct Visuo-Haptic Rendering of Partially Segmented Image Data.

    Science.gov (United States)

    Fortmeier, Dirk; Mastmeyer, Andre; Schröder, Julian; Handels, Heinz

    2016-01-01

    This study presents a new visuo-haptic virtual reality (VR) training and planning system for percutaneous transhepatic cholangio-drainage (PTCD) based on partially segmented virtual patient models. We only use partially segmented image data instead of a full segmentation and circumvent the necessity of surface or volume mesh models. Haptic interaction with the virtual patient during virtual palpation, ultrasound probing and needle insertion is provided. Furthermore, the VR simulator includes X-ray and ultrasound simulation for image-guided training. The visualization techniques are GPU-accelerated by implementation in Cuda and include real-time volume deformations computed on the grid of the image data. Computation on the image grid enables straightforward integration of the deformed image data into the visualization components. To provide shorter rendering times, the performance of the volume deformation algorithm is improved by a multigrid approach. To evaluate the VR training system, a user evaluation has been performed and deformation algorithms are analyzed in terms of convergence speed with respect to a fully converged solution. The user evaluation shows positive results with increased user confidence after a training session. It is shown that using partially segmented patient data and direct volume rendering is suitable for the simulation of needle insertion procedures such as PTCD.

  4. Non-photorealistic rendering of virtual implant models for computer-assisted fluoroscopy-based surgical procedures

    Science.gov (United States)

    Zheng, Guoyan

    2007-03-01

    Surgical navigation systems visualize the positions and orientations of surgical instruments and implants as graphical overlays onto a medical image of the operated anatomy on a computer monitor. The orthopaedic surgical navigation systems could be categorized according to the image modalities that are used for the visualization of surgical action. In the so-called CT-based systems or 'surgeon-defined anatomy' based systems, where a 3D volume or surface representation of the operated anatomy could be constructed from the preoperatively acquired tomographic data or through intraoperatively digitized anatomy landmarks, a photorealistic rendering of the surgical action has been identified to greatly improve usability of these navigation systems. However, this may not hold true when the virtual representation of surgical instruments and implants is superimposed onto 2D projection images in a fluoroscopy-based navigation system due to the so-called image occlusion problem. Image occlusion occurs when the field of view of the fluoroscopic image is occupied by the virtual representation of surgical implants or instruments. In these situations, the surgeon may miss part of the image details, even if transparency and/or wire-frame rendering is used. In this paper, we propose to use non-photorealistic rendering to overcome this difficulty. Laboratory testing results on foamed plastic bones during various computer-assisted fluoroscopybased surgical procedures including total hip arthroplasty and long bone fracture reduction and osteosynthesis are shown.

  5. 3D virtual rendering in thoracoscopic treatment of congenital malformation of the lung

    Directory of Open Access Journals (Sweden)

    Destro F.

    2013-10-01

    Full Text Available Introduction: Congenital malformations of the lung (CML are rare but potentially dangerous congenital malformations. Their identification is important in order to define the most appropriate management. Materials and methods: We retrospectively reviewed data from 37 patients affected by CML treated in our Pediatric Surgery Unit in the last four years with minimally invasive surgery (MIS. Results: Prenatal diagnosis was possible in 26/37 patients. Surgery was performed in the first month of life in 3 symptomatic patients and between 6 and 12 months in the others. All patients underwent radiological evaluation prior to thoracoscopic surgery. Images collected were reconstructed using the VR render software. Discussion and conclusions: Volume rendering gives high anatomical resolution and it can be useful to guide the surgical procedure. Thoracoscopy should be the technique of choice because it is safe, effective and feasible. Furthermore it has the benefit of a minimal access technique and it can be easily performed in children.

  6. 3D chromosome rendering from Hi-C data using virtual reality

    Science.gov (United States)

    Zhu, Yixin; Selvaraj, Siddarth; Weber, Philip; Fang, Jennifer; Schulze, Jürgen P.; Ren, Bing

    2015-01-01

    Most genome browsers display DNA linearly, using single-dimensional depictions that are useful to examine certain epigenetic mechanisms such as DNA methylation. However, these representations are insufficient to visualize intrachromosomal interactions and relationships between distal genome features. Relationships between DNA regions may be difficult to decipher or missed entirely if those regions are distant in one dimension but could be spatially proximal when mapped to three-dimensional space. For example, the visualization of enhancers folding over genes is only fully expressed in three-dimensional space. Thus, to accurately understand DNA behavior during gene expression, a means to model chromosomes is essential. Using coordinates generated from Hi-C interaction frequency data, we have created interactive 3D models of whole chromosome structures and its respective domains. We have also rendered information on genomic features such as genes, CTCF binding sites, and enhancers. The goal of this article is to present the procedure, findings, and conclusions of our models and renderings.

  7. Partial nephroureterectomy in duplex renal system: preoperative 3D virtual rendering and retroperitoneal laparoscopic approach in children

    Directory of Open Access Journals (Sweden)

    Molinaro F.

    2013-10-01

    Full Text Available Introduction: the aim of this study is to presents the results of our preliminary series of 8 partial nephroureterectomy performed by retroperitoneoscopy using harmonic scalpel with a preoperative 3D virtual reconstruction of bidimensional magnetic resonance images in children affected by duplication of the renal system. Materials and methods: We perform a retrospective study in our Pediatric Surgery Unit from January 2007 to January 2012 of all children affected by duplication of the renal system treated by retroperitoneal laparoscopic approach. Images collected were reconstructed using IRCAD VR render software. Data include: sex, age at surgery, clinical and radiological features, surgical procedure, follow-up and complications. Results: retroperitoneal laparoscopic partial nephroureterectomy was performed in 8 children (6 males and 2 females. All patients had a non-functioning moiety of a duplex kidney and in addition recurrent urinary tract infections. Two cases were associated with ureterocele; of them in one case we performed a previous endoscopic incision of the obstructing ureterocele. All patients underwent radiological evaluation prior to surgery, by ultrasound, voididng cystourethrography, renal scintigraphy and contrast-enhanced MRI evaluations. Images collected were reconstructed using IRCAD VR render software. Patients were treated by a 3-4 trocars technique and parenchymal section was performed using harmonic scalpel. The mean operative time was 180 minutes; no cases required open conversion. The mean hospital stay was 5 days. The mean follow-up was 38 months. No cases of secondary atrophy of the lower pole were observed. Discussion: Volume rendering gives high anatomical resolution and it can be useful to guide the surgical procedure. Laparoscopic retroperitoneal partial nephrectomy is a safe and feasible procedure in children for experienced pediatric laparoscopic surgeons.

  8. Is it possible to use highly realistic virtual reality in the elderly? A feasibility study with image-based rendering

    Directory of Open Access Journals (Sweden)

    Benoit M

    2015-03-01

    Full Text Available Michel Benoit,1,2 Rachid Guerchouche,3 Pierre-David Petit,1 Emmanuelle Chapoulie,3 Valeria Manera,1 Gaurav Chaurasia,3 George Drettakis,3 Philippe Robert1,4 1EA CoBTeK/IA, University of Nice Sophia Antipolis, 2Clinique de Psychiatrie, Pole des Neurosciences Cliniques, CHU de Nice, 3Institut National de Recherche en Informatique et en Automatique, Sophia-Antipolis, 4Centre Mémoire de Ressources et de Recherche, CHU de Nice, Nice, France Background: Virtual reality (VR opens up a vast number of possibilities in many domains of therapy. The primary objective of the present study was to evaluate the acceptability for elderly subjects of a VR experience using the image-based rendering virtual environment (IBVE approach and secondly to test the hypothesis that visual cues using VR may enhance the generation of autobiographical memories.Methods: Eighteen healthy volunteers (mean age 68.2 years presenting memory complaints with a Mini-Mental State Examination score higher than 27 and no history of neuropsychiatric disease were included. Participants were asked to perform an autobiographical fluency task in four conditions. The first condition was a baseline grey screen, the second was a photograph of a well-known location in the participant’s home city (FamPhoto, and the last two conditions displayed VR, ie, a familiar image-based virtual environment (FamIBVE consisting of an image-based representation of a known landmark square in the center of the city of experimentation (Nice and an unknown image-based virtual environment (UnknoIBVE, which was captured in a public housing neighborhood containing unrecognizable building fronts. After each of the four experimental conditions, participants filled in self-report questionnaires to assess the task acceptability (levels of emotion, motivation, security, fatigue, and familiarity. CyberSickness and Presence questionnaires were also assessed after the two VR conditions. Autobiographical memory was assessed

  9. Virtual/Real Transfer in a Large-Scale Environment: Impact of Active Navigation as a Function of the Viewpoint Displacement Effect and Recall Tasks

    Directory of Open Access Journals (Sweden)

    Grégory Wallet

    2013-01-01

    Full Text Available The purpose of this study was to examine the effect of navigation mode (passive versus active on the virtual/real transfer of spatial learning, according to viewpoint displacement (ground: 1 m 75 versus aerial: 4 m and as a function of the recall tasks used. We hypothesize that active navigation during learning can enhance performances when route strategy is favored by egocentric match between learning (ground-level viewpoint and recall (egocentric frame-based tasks. Sixty-four subjects (32 men and 32 women participated in the experiment. Spatial learning consisted of route learning in a virtual district (four conditions: passive/ground, passive/aerial, active/ground, or active/aerial, evaluated by three tasks: wayfinding, sketch-mapping, and picture-sorting. In the wayfinding task, subjects who were assigned the ground-level viewpoint in the virtual environment (VE performed better than those with the aerial-level viewpoint, especially in combination with active navigation. In the sketch-mapping task, aerial-level learning in the VE resulted in better performance than the ground-level condition, while active navigation was only beneficial in the ground-level condition. The best performance in the picture-sorting task was obtained with the ground-level viewpoint, especially with active navigation. This study confirmed the expected results that the benefit of active navigation was linked with egocentric frame-based situations.

  10. A Feasibility Study with Image-Based Rendered Virtual Reality in Patients with Mild Cognitive Impairment and Dementia.

    Science.gov (United States)

    Manera, Valeria; Chapoulie, Emmanuelle; Bourgeois, Jérémy; Guerchouche, Rachid; David, Renaud; Ondrej, Jan; Drettakis, George; Robert, Philippe

    2016-01-01

    Virtual Reality (VR) has emerged as a promising tool in many domains of therapy and rehabilitation, and has recently attracted the attention of researchers and clinicians working with elderly people with MCI, Alzheimer's disease and related disorders. Here we present a study testing the feasibility of using highly realistic image-based rendered VR with patients with MCI and dementia. We designed an attentional task to train selective and sustained attention, and we tested a VR and a paper version of this task in a single-session within-subjects design. Results showed that participants with MCI and dementia reported to be highly satisfied and interested in the task, and they reported high feelings of security, low discomfort, anxiety and fatigue. In addition, participants reported a preference for the VR condition compared to the paper condition, even if the task was more difficult. Interestingly, apathetic participants showed a preference for the VR condition stronger than that of non-apathetic participants. These findings suggest that VR-based training can be considered as an interesting tool to improve adherence to cognitive training in elderly people with cognitive impairment.

  11. A Feasibility Study with Image-Based Rendered Virtual Reality in Patients with Mild Cognitive Impairment and Dementia.

    Directory of Open Access Journals (Sweden)

    Valeria Manera

    Full Text Available Virtual Reality (VR has emerged as a promising tool in many domains of therapy and rehabilitation, and has recently attracted the attention of researchers and clinicians working with elderly people with MCI, Alzheimer's disease and related disorders. Here we present a study testing the feasibility of using highly realistic image-based rendered VR with patients with MCI and dementia. We designed an attentional task to train selective and sustained attention, and we tested a VR and a paper version of this task in a single-session within-subjects design. Results showed that participants with MCI and dementia reported to be highly satisfied and interested in the task, and they reported high feelings of security, low discomfort, anxiety and fatigue. In addition, participants reported a preference for the VR condition compared to the paper condition, even if the task was more difficult. Interestingly, apathetic participants showed a preference for the VR condition stronger than that of non-apathetic participants. These findings suggest that VR-based training can be considered as an interesting tool to improve adherence to cognitive training in elderly people with cognitive impairment.

  12. A Brief Introduction of the Achievements of Key Project Image-based Modeling and Rendering for Virtual Reality Applications

    Institute of Scientific and Technical Information of China (English)

    Jiaoying Shi; Zhanyi Hu; Enhua Wu; Qunsheng Peng

    2006-01-01

    @@ 1.Background The virtual reality (VR) technology is now at the frontier of modern information science.VR is based on computer graphics,computer vision,and other fresh air topics in today's computer technology.

  13. Single minimum incision endoscopic radical nephrectomy for renal tumors with preoperative virtual navigation using 3D-CT volume-rendering

    Directory of Open Access Journals (Sweden)

    Shioyama Yasukazu

    2010-04-01

    Full Text Available Abstract Background Single minimum incision endoscopic surgery (MIES involves the use of a flexible high-definition laparoscope to facilitate open surgery. We reviewed our method of radical nephrectomy for renal tumors, which is single MIES combined with preoperative virtual surgery employing three-dimensional CT images reconstructed by the volume rendering method (3D-CT images in order to safely and appropriately approach the renal hilar vessels. We also assessed the usefulness of 3D-CT images. Methods Radical nephrectomy was done by single MIES via the translumbar approach in 80 consecutive patients. We performed the initial 20 MIES nephrectomies without preoperative 3D-CT images and the subsequent 60 MIES nephrectomies with preoperative 3D-CT images for evaluation of the renal hilar vessels and the relation of each tumor to the surrounding structures. On the basis of the 3D information, preoperative virtual surgery was performed with a computer. Results Single MIES nephrectomy was successful in all patients. In the 60 patients who underwent 3D-CT, the number of renal arteries and veins corresponded exactly with the preoperative 3D-CT data (100% sensitivity and 100% specificity. These 60 nephrectomies were completed with a shorter operating time and smaller blood loss than the initial 20 nephrectomies. Conclusions Single MIES radical nephrectomy combined with 3D-CT and virtual surgery achieved a shorter operating time and less blood loss, possibly due to safer and easier handling of the renal hilar vessels.

  14. 一种基于两视点 DIBR 的改进虚拟视点合成方法%A modifiedtwo-viewpoint DIBR based virtual view synthesis method

    Institute of Scientific and Technical Information of China (English)

    王路; 赖春露

    2016-01-01

    The depth-image-based rendering (DIBR)is a classical virtual view synthesis technique which has been re-garded as one of the most crucial techniques for the naked eye three-dimensional television.In order to fill the holes ex-isted in the virtual images obtained by DIBR and thus to improve the quality of the images,a modified two-viewpoint DIBR based virtual view synthesis method is wasproposed.To prevent the image from severe geometry distortions while the number of holes being reduced,only those areas of the depth image with sudden changes on the depth value were preprocessed.In order to obtain virtual images without ghosting errors and large holes,the two virtual images generated from different viewpoints were dilated at first and then merged into one using a distance-and-depth based image blending algorithm proposed in this paper.To fill the residual holes after the image fusion,a shell-by-shell filling method was al-so presented.Experimental results show that the proposed method can obtain satisfactory performance in both subjective quality and objective evaluation.%虚拟视点合成是裸眼3D 电视的关键技术,而基于深度的图像渲染(depth-image-based rendering,DIBR)则是一种经典的虚拟视点合成方法。为解决经典 DIBR 方法存在的空洞问题,提高虚拟视点图像质量,提出了一种基于 DIBR 的改进虚拟视点合成方法。首先,只在深度边缘处进行深度图的预处理,这可减少空洞数量且不产生大的几何失真;其次,为得到既没有伪影也没有大空洞的虚拟视点图像,提出了基于距离与深度的图像融合方法,并在融合左右两侧参考视点目标图像前,对其空洞掩膜图进行膨胀;最后,利用逐层收缩的融合后空洞填充方法对剩余小空洞进行迭代填充。实验的主观质量与客观评价都显示本文方法能够取得令人满意的结果。

  15. Joint Projection Filling method for occlusion handling in Depth-Image-Based Rendering

    OpenAIRE

    Jantet, Vincent; Guillemot, Christine; Morin, Luce

    2011-01-01

    International audience; This paper addresses the disocclusion problem which may occur when using Depth-Image-Based Rendering (DIBR) techniques in 3DTV and Free-Viewpoint TV applications. A new DIBR technique is proposed, which combines three methods: a Joint Projection Filling (JPF) method to handle disocclusions in synthesized depth maps; a backward projection to synthesize virtual views; and a full-Z depth-aided inpainting to fill in disoccluded areas in textures. The JPF method performs th...

  16. High precision analysis of an embryonic extensional fault-related fold using 3D orthorectified virtual outcrops: The viewpoint importance in structural geology

    Science.gov (United States)

    Tavani, Stefano; Corradetti, Amerigo; Billi, Andrea

    2016-05-01

    Image-based 3D modeling has recently opened the way to the use of virtual outcrop models in geology. An intriguing application of this method involves the production of orthorectified images of outcrops using almost any user-defined point of view, so that photorealistic cross-sections suitable for numerous geological purposes and measurements can be easily generated. These purposes include the accurate quantitative analysis of fault-fold relationships starting from imperfectly oriented and partly inaccessible real outcrops. We applied the method of image-based 3D modeling and orthorectification to a case study from the northern Apennines, Italy, where an incipient extensional fault affecting well-layered limestones is exposed on a 10-m-high barely accessible cliff. Through a few simple steps, we constructed a high-quality image-based 3D model of the outcrop. In the model, we made a series of measurements including fault and bedding attitudes, which allowed us to derive the bedding-fault intersection direction. We then used this direction as viewpoint to obtain a distortion-free photorealistic cross-section, on which we measured bed dips and thicknesses as well as fault stratigraphic separations. These measurements allowed us to identify a slight difference (i.e. only 0.5°) between the hangingwall and footwall cutoff angles. We show that the hangingwall strain required to compensate the upward-decreasing displacement of the fault was accommodated by this 0.5° rotation (i.e. folding) and coeval 0.8% thickening of strata in the hangingwall relatively to footwall strata. This evidence is consistent with trishear fault-propagation folding. Our results emphasize the viewpoint importance in structural geology and therefore the potential of using orthorectified virtual outcrops.

  17. Quantum rendering

    Science.gov (United States)

    Lanzagorta, Marco O.; Gomez, Richard B.; Uhlmann, Jeffrey K.

    2003-08-01

    In recent years, computer graphics has emerged as a critical component of the scientific and engineering process, and it is recognized as an important computer science research area. Computer graphics are extensively used for a variety of aerospace and defense training systems and by Hollywood's special effects companies. All these applications require the computer graphics systems to produce high quality renderings of extremely large data sets in short periods of time. Much research has been done in "classical computing" toward the development of efficient methods and techniques to reduce the rendering time required for large datasets. Quantum Computing's unique algorithmic features offer the possibility of speeding up some of the known rendering algorithms currently used in computer graphics. In this paper we discuss possible implementations of quantum rendering algorithms. In particular, we concentrate on the implementation of Grover's quantum search algorithm for Z-buffering, ray-tracing, radiosity, and scene management techniques. We also compare the theoretical performance between the classical and quantum versions of the algorithms.

  18. Visuospatial viewpoint manipulation during full-body illusion modulates subjective first-person perspective.

    Science.gov (United States)

    Pfeiffer, Christian; Schmutz, Valentin; Blanke, Olaf

    2014-12-01

    Self-consciousness is based on multisensory signals from the body. In full-body illusion (FBI) experiments, multisensory conflict was used to induce changes in three key aspects of bodily self-consciousness (BSC): self-identification (which body 'I' identify with), self-location (where 'I' am located), and first-person perspective (from where 'I' experience the world; 1PP). Here, we adapted a previous FBI protocol in which visuotactile stroking was administered by a robotic device (tactile stroking) and simultaneously rendered on the back of a virtual body (visual stroking) that participants viewed on a head-mounted display as if filmed from a posterior viewpoint of a camera. We compared the effects of two different visuospatial viewpoints on the FBI and thereby on these key aspects of BSC. During control manipulations, participants saw a no-body object instead of a virtual body (first experiment) or received asynchronous versus synchronous visuotactile stroking (second experiment). Results showed that within-subjects visuospatial viewpoint manipulations affected the subjective 1PP ratings if a virtual body was seen but had no effect for viewing a non-body object. However, visuospatial viewpoint had no effect on self-identification, but depended on the viewed object and visuotactile synchrony. Self-location depended on visuospatial viewpoint (first experiment) and visuotactile synchrony (second experiment). Our results show that the visuospatial viewpoint from which the virtual body is seen during FBIs modulates the subjective 1PP and that such viewpoint manipulations contribute to spatial aspects of BSC. We compare the present data with recent data revealing vestibular contributions to the subjective 1PP and discuss the multisensory nature of BSC and the subjective 1PP.

  19. 基于虚拟化硬件3D图形加速的渲染云框架%A Rendering Cloud Frame Based on 3D-Graphics-Accelerating Technique for Virtualization

    Institute of Scientific and Technical Information of China (English)

    王总辉; 史梳酥; 陈文智

    2012-01-01

    Rendering cloud is one specific part of cloud computing. At the same time, as a typical example of the trend which extends compute-intensive applications to cloud, it has a bright future. The main works that are directly related to it now are classical rendering clusters and Nvidia' s reality server platform. However, the former could not support virtualization, which is one of the bases of cloud computing, and the latter puts limitation on the hardware that a rendering cloud could use, plus it could not support different GPU to work together. This paper has an analysis on 3D graphics accelerating technique for virtualization, such as VMGL, VMware, Xen and VirtualBox. Then it compares the practicability of expanding 3D graphics accelerating solutions to rendering cloud. After that, the paper proposes a rendering cluster which is based on VMGL. At last, it has a further step on the rendering cluster and finally comes up with a flexible rendering cloud frame which is based on virtualization and can support different GPU to work together.%渲染云作为云计算的一个特定细分,同时作为把对计算能力敏感的应用程序扩展到云计算这一趋势的典型代表,具有广阔的发展前景.当前与渲染云直接相关的工作主要有传统的各种渲染集群以及Nvidia的RealityServer平台.但是前者不支持作为云计算基础的虚拟化技术,后者限制了渲染云平台的硬件,并且不能整合各种不同的图形加速设备使其协同工作.本文首先分析了VMGL、VMware、Xen以及VirtualBox等虚拟机3D图形加速技术,并对用这些技术实现渲染云的可行性进行比较,提出了基于VMGL的渲染集群方案.接着在渲染集群的基础上对渲染云相关技术进行了研究,提出了一个灵活、能够支持不同3D图形加速设备协同工作的、基于虚拟化的渲染云框架.

  20. Diagnostic Value of Multidetector CT and Its Multiplanar Reformation, Volume Rendering and Virtual Bronchoscopy Postprocessing Techniques for Primary Trachea and Main Bronchus Tumors.

    Directory of Open Access Journals (Sweden)

    Mingyue Luo

    Full Text Available To evaluate the diagnostic value of multidetector CT (MDCT and its multiplanar reformation (MPR, volume rendering (VR and virtual bronchoscopy (VB postprocessing techniques for primary trachea and main bronchus tumors.Detection results of 31 primary trachea and main bronchus tumors with MDCT and its MPR, VR and VB postprocessing techniques, were analyzed retrospectively with regard to tumor locations, tumor morphologies, extramural invasions of tumors, longitudinal involvements of tumors, morphologies and extents of luminal stenoses, distances between main bronchus tumors and trachea carinae, and internal features of tumors. The detection results were compared with that of surgery and pathology.Detection results with MDCT and its MPR, VR and VB were consistent with that of surgery and pathology, included tumor locations (tracheae, n = 19; right main bronchi, n = 6; left main bronchi, n = 6, tumor morphologies (endoluminal nodes with narrow bases, n = 2; endoluminal nodes with wide bases, n = 13; both intraluminal and extraluminal masses, n = 16, extramural invasions of tumors (brokethrough only serous membrane, n = 1; 4.0 mm-56.0 mm, n = 14; no clear border with right atelectasis, n = 1, longitudinal involvements of tumors (3.0 mm, n = 1; 5.0 mm-68.0 mm, n = 29; whole right main bronchus wall and trachea carina, n = 1, morphologies of luminal stenoses (irregular, n = 26; circular, n = 3; eccentric, n = 1; conical, n = 1 and extents (mild, n = 5; moderate, n = 7; severe, n = 19, distances between main bronchus tumors and trachea carinae (16.0 mm, n = 1; invaded trachea carina, n = 1; >20.0 mm, n = 10, and internal features of tumors (fairly homogeneous densities with rather obvious enhancements, n = 26; homogeneous density with obvious enhancement, n = 1; homogeneous density without obvious enhancement, n = 1; not enough homogeneous density with obvious enhancement, n = 1; punctate calcification with obvious enhancement, n = 1; low density

  1. 基于动态局部更新体素模型的虚拟加工仿真算法研究%Research on Virtual Machining Simulation Algorithm Based on Dynamic Partial Rendering for Voxel Model

    Institute of Scientific and Technical Information of China (English)

    李妞; 陈成军; 陈韩燕

    2011-01-01

    为提高虚拟加工仿真算法的仿真速度和精度,提出一种新的基于动态局部更新体素模型的虚拟加工仿真算法.该算法利用体素节点间的邻接关系,实现虚拟加工仿真的动态局部更新.算法在初始化阶段建立虚拟毛坯的八叉树结构体素模型,并建立任意体素6-邻接关系遍历算法.在虚拟加工几何仿真阶段,利用刀具和毛坯相对运动的时空一致性,从毛坯上一帧已碰撞体素集向周围扩散依次检测其邻接体素是否与刀具发生碰撞,并根据碰撞情况动态修改已碰撞体素的参数,直到所有邻接体素均未与刀具发生碰撞,从而实现虚拟加工仿真的动态局部更新,提高了算法的速度与精度.最后通过铣削虚拟加工仿真验证本文所提出算法的可行性和有效性.%To improve the speed and accuracy of virtual machining simulation, a new algorithm of dynamic partial rendering for voxel model-based virtual machining simulation is proposed. It uses voxel adjacency relationship between nodes to achieve dynamic partial rendering. In initialization stage, both octree structure voxel model for virtual rough and adjacency traversal algorithm of any voxel are modeled. In stage of virtual machine simulation, the collision detection is conducted from voxels that collided with virtual tool in last frame, and spreads to their adjacent voxels calculated using adjacency traversal algorithm. If some tested voxel is collided with virtual tool, its parameter will be modified dynamically. So dynamic partial rendering in virtual machine simulation is realized. Finally, a simple five-axis milling virtual machining experiments is setted, which shows that the presented algorithm is feasible and effective.

  2. Light field rendering with omni-directional camera

    Science.gov (United States)

    Todoroki, Hiroshi; Saito, Hideo

    2003-06-01

    This paper presents an approach to capture visual appearance of a real environment such as an interior of a room. We propose the method for generating arbitrary viewpoint images by building light field with the omni-directional camera, which can capture the wide circumferences. Omni-directional camera used in this technique is a special camera with the hyperbolic mirror in the upper part of a camera, so that we can capture luminosity in the environment in the range of 360 degree of circumferences in one image. We apply the light field method, which is one technique of Image-Based-Rendering(IBR), for generating the arbitrary viewpoint images. The light field is a kind of the database that records the luminosity information in the object space. We employ the omni-directional camera for constructing the light field, so that we can collect many view direction images in the light field. Thus our method allows the user to explore the wide scene, that can acheive realistic representation of virtual enviroment. For demonstating the proposed method, we capture image sequence in our lab's interior environment with an omni-directional camera, and succesfully generate arbitray viewpoint images for virual tour of the environment.

  3. Computer Haptics:Haptic Modeling and Rendering in Virtual Reality Environments%计算机触觉:虚拟现实环境的力触觉建模和生成

    Institute of Scientific and Technical Information of China (English)

    王党校; 焦健; 张玉茹; 赵晓含

    2016-01-01

    The haptic channel is one of the five sensory channels of human. It plays an indispensable role in eve-ryday life. In the virtual reality and augmented reality systems, the haptic feedback is expected to significantly improve immersion and interactivity of human-computer interaction (HCI). This paper reviews the haptic model-ing and rendering technologies in virtual reality environments. From the perspective of the haptic and visual ren-dering differences, we summarize the history and current situation of research in the haptic field, and analyze the key technology of virtual object modeling, collision detection, collision response, force/torque computation and so on. Finally, we propose trends and future research challenges in haptic rendering.%触觉是人类5种感觉通道之一,在日常生活中发挥着不可缺少的作用。在虚拟现实和增强现实系统中,力触觉反馈的引入有望显著提高人机交互的沉浸感和交互性。文中综述了虚拟现实环境中力触觉感受的建模和生成方法,从力触觉生成与视觉生成的差异性出发,回顾了计算机触觉的发展历史和国内外研究现状,重点分析了虚拟物体建模、碰撞检测、碰撞响应、变形计算等关键技术,并提出了力触觉生成技术的未来发展趋势和技术挑战。

  4. Optimization-Based Wearable Tactile Rendering.

    Science.gov (United States)

    Perez, Alvaro G; Lobo, Daniel; Chinello, Francesco; Cirio, Gabriel; Malvezzi, Monica; San Martin, Jose; Prattichizzo, Domenico; Otaduy, Miguel A

    2016-10-20

    Novel wearable tactile interfaces offer the possibility to simulate tactile interactions with virtual environments directly on our skin. But, unlike kinesthetic interfaces, for which haptic rendering is a well explored problem, they pose new questions about the formulation of the rendering problem. In this work, we propose a formulation of tactile rendering as an optimization problem, which is general for a large family of tactile interfaces. Based on an accurate simulation of contact between a finger model and the virtual environment, we pose tactile rendering as the optimization of the device configuration, such that the contact surface between the device and the actual finger matches as close as possible the contact surface in the virtual environment. We describe the optimization formulation in general terms, and we also demonstrate its implementation on a thimble-like wearable device. We validate the tactile rendering formulation by analyzing its force error, and we show that it outperforms other approaches.

  5. ARC Code TI: SLAB Spatial Audio Renderer

    Data.gov (United States)

    National Aeronautics and Space Administration — SLAB is a software-based, real-time virtual acoustic environment rendering system being developed as a tool for the study of spatial hearing. SLAB is designed to...

  6. 虚拟装配中基于导纳控制的力觉渲染技术%Haptic Rendering Technology Based on Admittance Control in Virtual Assembly

    Institute of Scientific and Technical Information of China (English)

    史建成; 刘检华; 宁汝新; 侯伟伟

    2012-01-01

    In conventional haptic feedback technologies, impedance control is used as the main control mode, which can hardly meet the requirements in virtual assembly. Admittance control mode is more suitable for haptic rendering. The framework and algorithms of the haptic rendering based on admittance control mode are presented. First, dynamics model used for admittance control is given, and haptic rendering under the states of collision and constraint are discussed. Second, to solve the problem of small clearance assembly, a method of haptic rendering combining physical constraints with geometric constraint is presented. Third, the method of quadratic Lagrangian interpolation is adopted, aiming at solving the problem of asynchrony between haptic feedback loop and physical computing loop to maintain the stability of the haptic device. The algorithms are implemented and the haptic device is connected and utilized in the virtual assembly process planning system (VAPP). The results show that the algorithms can meet the need of haptic interaction in the virtual assembly system.%传统的力触觉渲染多采用阻抗控制,不能很好地满足虚拟装配的应用要求,相比之下导纳控制模式更适用这一领域.为此提出一种基于导纳控制的双线程力觉渲染构架,并给出相应的力觉渲染算法.首先建立用于导纳控制的动力学模型,并讨论了碰撞和约束这2个状态下的力觉渲染;为了使用力觉交互接口进行虚拟装配中的小间隙装配,提出物理约束与几何约束结合的力觉渲染方法;最后针对物理计算和力反馈循环2个线程刷新频率不匹配的问题,利用二次拉格朗日多项式进行数值插值,实现了力觉交互接口的平稳输出.通过力反馈设备与自主开发的虚拟装配原型系统VAPP的连接与应用,验证了所提出的算法满足虚拟装配系统中力觉交互的应用要求.

  7. Practical Parallel Rendering

    CERN Document Server

    Chalmers, Alan

    2002-01-01

    Meeting the growing demands for speed and quality in rendering computer graphics images requires new techniques. Practical parallel rendering provides one of the most practical solutions. This book addresses the basic issues of rendering within a parallel or distributed computing environment, and considers the strengths and weaknesses of multiprocessor machines and networked render farms for graphics rendering. Case studies of working applications demonstrate, in detail, practical ways of dealing with complex issues involved in parallel processing.

  8. Haptic rendering foundations, algorithms, and applications

    CERN Document Server

    Lin, Ming C

    2008-01-01

    For a long time, human beings have dreamed of a virtual world where it is possible to interact with synthetic entities as if they were real. It has been shown that the ability to touch virtual objects increases the sense of presence in virtual environments. This book provides an authoritative overview of state-of-theart haptic rendering algorithms and their applications. The authors examine various approaches and techniques for designing touch-enabled interfaces for a number of applications, including medical training, model design, and maintainability analysis for virtual prototyping, scienti

  9. Viewpoint Consistency: An Eye Movement Study

    Directory of Open Access Journals (Sweden)

    Filipe Cristino

    2012-05-01

    Full Text Available Eye movements have been widely studied, using images and videos in laboratories or portable eye trackers in the real world. Although a good understanding of the saccadic system and extensive models of gaze have been developed over the years, only a few studies have focused on the consistency of eye movements across viewpoints. We have developed a new technique to compute and map the depth of collected eye movements on stimuli rendered from 3D mesh objects using a traditional corneal reflection eye tracker (SR Eyelink 1000. Having eye movements mapped into 3D space (and not on an image space allowed us to compare fixations across viewpoints. Fixation sequences (scanpaths were also studied across viewpoints using the ScanMatch method (Cristino et al 2010, Behavioural and Research Methods 42, 692–700, extended to work with 3D eye movements. In a set of experiments where participants were asked to perform a recognition task on either a set of objects or faces, we recorded their gaze while performing the task. Participants either viewed the stimuli in 2D or using anaglyph glasses. The stimuli were shown from different viewpoints during the learning and testing phases. A high degree of gaze consistency was found across the different viewpoints, particularly between learning and testing phases. Scanpaths were also similar across viewpoints, suggesting not only that the gazed spatial locations are alike, but also their temporal order.

  10. View compensated compression of volume rendered images for remote visualization.

    Science.gov (United States)

    Lalgudi, Hariharan G; Marcellin, Michael W; Bilgin, Ali; Oh, Han; Nadar, Mariappan S

    2009-07-01

    Remote visualization of volumetric images has gained importance over the past few years in medical and industrial applications. Volume visualization is a computationally intensive process, often requiring hardware acceleration to achieve a real time viewing experience. One remote visualization model that can accomplish this would transmit rendered images from a server, based on viewpoint requests from a client. For constrained server-client bandwidth, an efficient compression scheme is vital for transmitting high quality rendered images. In this paper, we present a new view compensation scheme that utilizes the geometric relationship between viewpoints to exploit the correlation between successive rendered images. The proposed method obviates motion estimation between rendered images, enabling significant reduction to the complexity of a compressor. Additionally, the view compensation scheme, in conjunction with JPEG2000 performs better than AVC, the state of the art video compression standard.

  11. Video-based rendering

    CERN Document Server

    Magnor, Marcus A

    2005-01-01

    Driven by consumer-market applications that enjoy steadily increasing economic importance, graphics hardware and rendering algorithms are a central focus of computer graphics research. Video-based rendering is an approach that aims to overcome the current bottleneck in the time-consuming modeling process and has applications in areas such as computer games, special effects, and interactive TV. This book offers an in-depth introduction to video-based rendering, a rapidly developing new interdisciplinary topic employing techniques from computer graphics, computer vision, and telecommunication en

  12. Study on the Supporting Role of the Computer Cluster Rendering Network in the Creation of Virtual Reality Art Form%计算机集群化网络渲染对虚拟现实艺术创作辅助作用的研究

    Institute of Scientific and Technical Information of China (English)

    张亭; 高树清

    2012-01-01

    With the creation of virtual reality art form widely used in artistic creation, there are higher demands on the technology of the corresponding auxiliary. Traditional single server can' t render complex virtual reality works of art. The computer cluster is established to render the network of virtual reality art form to create a virtual interactive environment, so as to achieve more efficient and more perfect rendering.%随着虚拟现实艺术创作形式在艺术创作中广泛应用,对相应辅助的技术会提出更高的要求。传统的单一服务器无法有效渲染复杂虚拟现实艺术作品,通过建立计算机集群化网络渲染对虚拟现实艺术形式创作出虚拟交互环境的实现有着更高效、更完美的呈现效果。

  13. 3D virtual reconstruction of the choir of the Convent of Santa Clara in Toro (Zamora: recovering a medieval space of female devotion through photogrammetric recording and rendering techniques

    Directory of Open Access Journals (Sweden)

    Fernando Gutiérrez Baños

    2016-11-01

    Full Text Available The Convent of Santa Clara in Toro (Zamora was founded in the mid-13th century. After destruction during the Castilian civil struggles of the last years of this century, its fabric was rebuilt and it was inhabited again by the Clarissan nuns, who still occupy it.  Its architecture corresponds for the most part to its early-14th century rebuilding, even though it is concealed by works carried out from the 16th to the 18th centuries, so that it is apparently a Baroque complex.  In the 1950s, in the choir of this Medieval hidden structure, a set of wall paintings of the mid-14thcentury was brought to light (one of the most important set of wall paintings of the early Gothic period ever found in Castile, but they were immediately detached from the walls and sold. It was only after a combination of circumstances that they came back to Toro to be installed in another building, the church of San Sebastián de los Caballeros, transformed into a museum. As a consequence of all these operations, the arrangement and sense of these wall paintings was lost. The virtual three-dimensional (3D reconstruction, based on a deep analysis and criticism of historical sources and on a close inspection and photogrammetric recording of the original room once occupied by the wall paintings, enables us to place them back in their original context through the use of rendering techniques, so recovering one of the most exciting spaces of female devotion of the Castilian 14thcentury.

  14. Anti-Aliased Rendering of Water Surface

    Institute of Scientific and Technical Information of China (English)

    Xue-Ying Qin; Eihachiro Nakamae; Wei Hua; Yasuo Nagai; Qun-Sheng Peng

    2004-01-01

    Water surface is one of the most important components of landscape scenes. When rendering spacious far from the viewpoint. This is because water surface consists of stochastic water waves which are usually modeled by periodic bump mapping. The incident rays on the water surface are actually scattered by the bumped waves,pattern, we estimate this solid angle of reflected rays and trace these rays. An image-based accelerating method is adopted so that the contribution of each reflected ray can be quickly obtained without elaborate intersection calculation. We also demonstrate anti-aliased shadows of sunlight and skylight on the water surface. Both the rendered images and animations show excellent effects on the water surface of a reservoir.

  15. Adaptive Rendering Based on Visual Acuity Equations

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new method of adaptable rendering for interaction in Virtual Environment(VE) through different visual acuity equations is proposed. An acuity factor equation of luminance vision is first given. Secondly, five equations which calculate the visual acuity through visual acuity factors are presented, and adaptive rendering strategy based on different visual acuity equations is given. The VE system may select one of them on the basis of the host's load, hereby select LOD for each model which would be rendered. A coarser LOD is selected where the visual acuity is lower, and a better LOD is used where it is higher. This method is tested through experiments and the experimental results show that it is effective.

  16. Haptic rendering for dental training system

    Institute of Scientific and Technical Information of China (English)

    WANG DangXiao; ZHANG YuRu; WANG Yong; L(U) PeiJun; ZHOU RenGe; ZHOU WanLin

    2009-01-01

    Immersion and Interaction are two key features of virtual reality systems,which are especially important for medical applications.Based on the requirement of motor skill training in dental surgery,haptic rendering method based on triangle model is investigated in this paper.Multi-rate haptic rendering architecture is proposed to solve the contradiction between fidelity and efficiency requirements.Realtime collision detection algorithm based on spatial partition and time coherence is utilized to enable fast contact determination.Proxy-based collision response algorithm is proposed to compute surface contact point.Cutting force model based on piecewise contact transition model is proposed for dental drilling simulation during tooth preparation.Velocity-driven levels of detail hapUc rendering algorithm is proposed to maintain high update rate for complex scenes with a large number of triangles.Hapticvisual collocated dental training prototype is established using half-mirror solution.Typical dental operations have been realized Including dental caries exploration,detection of boundary within dental crose-section plane,and dental drilling during tooth preparation.The haptic rendering method is a fundamental technology to improve Immersion and interaction of virtual reality training systems,which is useful not only in dental training,but also in other surgical training systems.

  17. Realistic Real-Time Outdoor Rendering in Augmented Reality

    Science.gov (United States)

    Kolivand, Hoshang; Sunar, Mohd Shahrizal

    2014-01-01

    Realistic rendering techniques of outdoor Augmented Reality (AR) has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps). Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems. PMID:25268480

  18. Realistic real-time outdoor rendering in augmented reality.

    Science.gov (United States)

    Kolivand, Hoshang; Sunar, Mohd Shahrizal

    2014-01-01

    Realistic rendering techniques of outdoor Augmented Reality (AR) has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps). Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems.

  19. Realistic real-time outdoor rendering in augmented reality.

    Directory of Open Access Journals (Sweden)

    Hoshang Kolivand

    Full Text Available Realistic rendering techniques of outdoor Augmented Reality (AR has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps. Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems.

  20. Rendering the Topological Spines

    Energy Technology Data Exchange (ETDEWEB)

    Nieves-Rivera, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-05-05

    Many tools to analyze and represent high dimensional data already exits yet most of them are not flexible, informative and intuitive enough to help the scientists make the corresponding analysis and predictions, understand the structure and complexity of scientific data, get a complete picture of it and explore a greater number of hypotheses. With this in mind, N-Dimensional Data Analysis and Visualization (ND²AV) is being developed to serve as an interactive visual analysis platform with the purpose of coupling together a number of these existing tools that range from statistics, machine learning, and data mining, with new techniques, in particular with new visualization approaches. My task is to create the rendering and implementation of a new concept called topological spines in order to extend ND²AV's scope. Other existing visualization tools create a representation preserving either the topological properties or the structural (geometric) ones because it is challenging to preserve them both simultaneously. Overcoming such challenge by creating a balance in between them, the topological spines are introduced as a new approach that aims to preserve them both. Its render using OpenGL and C++ and is currently being tested to further on be implemented on ND²AV. In this paper I will present what are the Topological Spines and how they are rendered.

  1. High Fidelity Haptic Rendering

    CERN Document Server

    Otaduy, Miguel A

    2006-01-01

    The human haptic system, among all senses, provides unique and bidirectional communication between humans and their physical environment. Yet, to date, most human-computer interactive systems have focused primarily on the graphical rendering of visual information and, to a lesser extent, on the display of auditory information. Extending the frontier of visual computing, haptic interfaces, or force feedback devices, have the potential to increase the quality of human-computer interaction by accommodating the sense of touch. They provide an attractive augmentation to visual display and enhance t

  2. Binaural Rendering in MPEG Surround

    Directory of Open Access Journals (Sweden)

    Kristofer Kjörling

    2008-04-01

    Full Text Available This paper describes novel methods for evoking a multichannel audio experience over stereo headphones. In contrast to the conventional convolution-based approach where, for example, five input channels are filtered using ten head-related transfer functions, the current approach is based on a parametric representation of the multichannel signal, along with either a parametric representation of the head-related transfer functions or a reduced set of head-related transfer functions. An audio scene with multiple virtual sound sources is represented by a mono or a stereo downmix signal of all sound source signals, accompanied by certain statistical (spatial properties. These statistical properties of the sound sources are either combined with statistical properties of head-related transfer functions to estimate “binaural parameters” that represent the perceptually relevant aspects of the auditory scene or used to create a limited set of combined head-related transfer functions that can be applied directly on the downmix signal. Subsequently, a binaural rendering stage reinstates the statistical properties of the sound sources by applying the estimated binaural parameters or the reduced set of combined head-related transfer functions directly on the downmix. If combined with parametric multichannel audio coders such as MPEG Surround, the proposed methods are advantageous over conventional methods in terms of perceived quality and computational complexity.

  3. Binaural Rendering in MPEG Surround

    Science.gov (United States)

    Breebaart, Jeroen; Villemoes, Lars; Kjörling, Kristofer

    2008-12-01

    This paper describes novel methods for evoking a multichannel audio experience over stereo headphones. In contrast to the conventional convolution-based approach where, for example, five input channels are filtered using ten head-related transfer functions, the current approach is based on a parametric representation of the multichannel signal, along with either a parametric representation of the head-related transfer functions or a reduced set of head-related transfer functions. An audio scene with multiple virtual sound sources is represented by a mono or a stereo downmix signal of all sound source signals, accompanied by certain statistical (spatial) properties. These statistical properties of the sound sources are either combined with statistical properties of head-related transfer functions to estimate "binaural parameters" that represent the perceptually relevant aspects of the auditory scene or used to create a limited set of combined head-related transfer functions that can be applied directly on the downmix signal. Subsequently, a binaural rendering stage reinstates the statistical properties of the sound sources by applying the estimated binaural parameters or the reduced set of combined head-related transfer functions directly on the downmix. If combined with parametric multichannel audio coders such as MPEG Surround, the proposed methods are advantageous over conventional methods in terms of perceived quality and computational complexity.

  4. Discrimination. Opposing Viewpoints Series.

    Science.gov (United States)

    Williams, Mary E., Ed.

    Books in the Opposing Viewpoints series challenge readers to question their own opinions and assumptions. By reading carefully balanced views, readers confront new ideas on the topic of interest. The Civil Rights Act of 1964, which prohibited job discrimination based on age, race, religion, gender, or national origin, provided the groundwork for…

  5. Foggy Scene Rendering Based on Transmission Map Estimation

    Directory of Open Access Journals (Sweden)

    Fan Guo

    2014-01-01

    Full Text Available Realistic rendering of foggy scene is important in game development and virtual reality. Traditional methods have many parameters to control or require a long time to compute, and they are usually limited to depicting a homogeneous fog without considering the foggy scene with heterogeneous fog. In this paper, a new rendering method based on transmission map estimation is proposed. We first generate perlin noise image as the density distribution texture of heterogeneous fog. Then we estimate the transmission map using the Markov random field (MRF model and the bilateral filter. Finally, virtual foggy scene is realistically rendered with the generated perlin noise image and the transmission map according to the atmospheric scattering model. Experimental results show that the rendered results of our approach are quite satisfactory.

  6. ARE: Ada Rendering Engine

    Directory of Open Access Journals (Sweden)

    Stefano Penge

    2009-10-01

    Full Text Available E' ormai pratica diffusa, nello sviluppo di applicazioni web, l'utilizzo di template e di potenti template engine per automatizzare la generazione dei contenuti da presentare all'utente. Tuttavia a volte la potenza di tali engine è€ ottenuta mescolando logica e interfaccia, introducendo linguaggi diversi da quelli di descrizione della pagina, o addirittura inventando nuovi linguaggi dedicati.ARE (ADA Rendering Engine è€ pensato per gestire l'intero flusso di creazione del contenuto HTML/XHTML dinamico, la selezione del corretto template, CSS, JavaScript e la produzione dell'output separando completamente logica e interfaccia. I templates utilizzati sono puro HTML senza parti in altri linguaggi, e possono quindi essere gestiti e visualizzati autonomamente. Il codice HTML generato è€ uniforme e parametrizzato.E' composto da due moduli, CORE (Common Output Rendering Engine e ALE (ADA Layout Engine.Il primo (CORE viene utilizzato per la generazione OO degli elementi del DOM ed è pensato per aiutare lo sviluppatore nella produzione di codice valido rispetto al DTD utilizzato. CORE genera automaticamente gli elementi del DOM in base al DTD impostato nella configurazioneIl secondo (ALE viene utilizzato come template engine per selezionare automaticamente in base ad alcuni parametri (modulo, profilo utente, tipologia del nodo, del corso, preferenze di installazione il template HTML, i CSS e i file JavaScript appropriati. ALE permette di usare templates di default e microtemplates ricorsivi per semplificare il lavoro del grafico.I due moduli possono in ogni caso essere utilizzati indipendentemente l'uno dall'altro. E' possibile generare e renderizzare una pagina HTML utilizzando solo CORE oppure inviare gli oggetti CORE al template engine ALE che provvede a renderizzare la pagina HTML. Viceversa è possibile generare HTML senza utilizzare CORE ed inviarlo al template engine ALECORE è alla prima release ed è€ già utilizzato all

  7. THE VIEWPOINT MANAGEMENT

    Directory of Open Access Journals (Sweden)

    R. Neuville

    2016-10-01

    Full Text Available This paper deals with the viewpoint management in 3D environments considering an allocentric environment. The recent advances in computer sciences and the growing number of affordable remote sensors lead to impressive improvements in the 3D visualisation. Despite some research relating to the analysis of visual variables used in 3D environments, we notice that it lacks a real standardisation of 3D representation rules. In this paper we study the “viewpoint” as being the first considered parameter for a normalised visualisation of 3D data. Unlike in a 2D environment, the viewing direction is not only fixed in a top down direction in 3D. A non-optimal camera location means a poor 3D representation in terms of relayed information. Based on this statement we propose a model based on the analysis of the computational display pixels that determines a viewpoint maximising the relayed information according to one kind of query. We developed an OpenGL prototype working on screen pixels that allows to determine the optimal camera location based on a screen pixels colour algorithm. The viewpoint management constitutes a first step towards a normalised 3D geovisualisation.

  8. Parallel hierarchical radiosity rendering

    Energy Technology Data Exchange (ETDEWEB)

    Carter, M.

    1993-07-01

    In this dissertation, the step-by-step development of a scalable parallel hierarchical radiosity renderer is documented. First, a new look is taken at the traditional radiosity equation, and a new form is presented in which the matrix of linear system coefficients is transformed into a symmetric matrix, thereby simplifying the problem and enabling a new solution technique to be applied. Next, the state-of-the-art hierarchical radiosity methods are examined for their suitability to parallel implementation, and scalability. Significant enhancements are also discovered which both improve their theoretical foundations and improve the images they generate. The resultant hierarchical radiosity algorithm is then examined for sources of parallelism, and for an architectural mapping. Several architectural mappings are discussed. A few key algorithmic changes are suggested during the process of making the algorithm parallel. Next, the performance, efficiency, and scalability of the algorithm are analyzed. The dissertation closes with a discussion of several ideas which have the potential to further enhance the hierarchical radiosity method, or provide an entirely new forum for the application of hierarchical methods.

  9. Sea modeling and rendering

    Science.gov (United States)

    Cathala, Thierry; Latger, Jean

    2010-10-01

    More and more defence and civil applications require simulation of marine synthetic environment. Currently, the "Future Anti-Surface-Guided-Weapon" (FASGW) or "anti-navire léger" (ANL) missile needs this kind of modelling. This paper presents a set of technical enhancement of the SE-Workbench that aim at better representing the sea profile and the interaction with targets. The operational scenario variability is a key criterion: the generic geographical area (e.g. Persian Gulf, coast of Somalia,...), the type of situation (e.g. peace keeping, peace enforcement, anti-piracy, drug interdiction,...)., the objectives (political, strategic, or military objectives), the description of the mission(s) (e.g. antipiracy) and operation(s) (e.g. surveillance and reconnaissance, escort, convoying) to achieve the objectives, the type of environment (Weather, Time of day, Geography [coastlines, islands, hills/mountains]). The paper insists on several points such as the dual rendering using either ray tracing [and the GP GPU optimization] or rasterization [and GPU shaders optimization], the modelling of sea-surface based on hypertextures and shaders, the wakes modelling, the buoyancy models for targets, the interaction of coast and littoral, the dielectric infrared modelling of water material.

  10. Research of global illumination algorithms rendering in glossy scene

    Institute of Scientific and Technical Information of China (English)

    BAI Shuangxue; ZHANG Qiang; ZHOU Dongsheng

    2012-01-01

    In computer graphic (CG), illumination rendering generated realistic effect at virtual scene is amazing. Not only plausible lighting effect is to show the relative position between of the objects, but also to reflect the material of visual appearance of the vir- tual objects. The diffuse-scene rendering reflectance credibility has gradually matured. Global illumination rendering method for the glossy material is still a challenge for the CG research. Because of the shiny materials is highly energy reflection between the com- plex light paths. Whether we trace glossy reflection paths, or use of one-reflection or multi-reflection approximate above complex il- lumination transmission is a difficult working. This paper we gather some commonly used global illumination algorithms recently year and its extension glossy scene improvements. And we introduce the limitation of classical algorithms rendering glossy scene and some extended solution. Finally, we will summarize the illumination rendering for specular scene, there are still some open prob- lems.

  11. Haptic Rendering Techniques for Non-Physical, Command Decision Support

    Science.gov (United States)

    2004-04-01

    tactile and haptic rendering techniques. BACKGROUND Usually visualizing battlefield implies maps, computer screens filled with information and perhaps 3...Traditional 2-D Screens 3-D stereo glasses HMD CAVE Audio Haptics Level 1, 2 3 …..Fusion - Estimates INTEL SATELLITE RAW DATA Transforms...sensory modes of data presentation Haptics Tactile 8-14 Virtual Lexicon Haptic feedback The sensation of weight or resistance in a virtual world. (from

  12. A Multiresolution Image Cache for Volume Rendering

    Energy Technology Data Exchange (ETDEWEB)

    LaMar, E; Pascucci, V

    2003-02-27

    The authors discuss the techniques and implementation details of the shared-memory image caching system for volume visualization and iso-surface rendering. One of the goals of the system is to decouple image generation from image display. This is done by maintaining a set of impostors for interactive display while the production of the impostor imagery is performed by a set of parallel, background processes. The system introduces a caching basis that is free of the gap/overlap artifacts of earlier caching techniques. instead of placing impostors at fixed, pre-defined positions in world space, the technique is to adaptively place impostors relative to the camera viewpoint. The positions translate with the camera but stay aligned to the data; i.e., the positions translate, but do not rotate, with the camera. The viewing transformation is factored into a translation transformation and a rotation transformation. The impostor imagery is generated using just the translation transformation and visible impostors are displayed using just the rotation transformation. Displayed image quality is improved by increasing the number of impostors and the frequency that impostors are re-rendering is improved by decreasing the number of impostors.

  13. Viewpoints on Grid Standards

    Institute of Scientific and Technical Information of China (English)

    Andrew A. Chien; Xian-He Sun; Zhi-Wei Xu

    2005-01-01

    @@ At GCC 2003 in Shanghai in December 2003, a panel discussion was held on the future of grid computing and on the role of the Globus Toolkit in future grid standards. Panelists include Andrew Chien (UCSD, USA), Wolfgang Gentzsch (Sun),Francis Lau (HKU, China), Carl Kesselman (USC, USA), Satoshi Matsuoka (TIT, Japan), Xian-He Sun (IIT, USA), Richard Wirt (Intel), Liang-Jie Zhang (IBM Research), Song-Nian Zhou (Platform Computing), and Zhi-Wei Xu (ICT, China), with Hai Jin (HUST, China) served as the coordinator. The panel talks were stimulating and well received. Three of the panel talk notes are selected and included in this viewpoint.

  14. Volumetric Virtual Environments

    Institute of Scientific and Technical Information of China (English)

    HE Taosong

    2000-01-01

    Driven by fast development of both virtual reality and volume visualization, we discuss some critical techniques towards building a volumetric VR system, specifically the modeling, rendering, and manipulations of a volumetric scene.Techniques such as voxel-based object simplification, accelerated volume rendering,fast stereo volume rendering, and volumetric "collision detection" are introduced and improved, with the idea of demonstrating the possibilities and potential benefits of incorporating volumetric models into VR systems.

  15. Virtual Library: An essential component of virtual education

    Directory of Open Access Journals (Sweden)

    M zarghani

    2015-06-01

    Full Text Available Abstract Introduction: Library is one of the essential elements of universities which provide some important educational needs of students. Virtual education can not be exempted and virtual libraries are important support for virtual training programs. The purpose of this study is to evaluate the viewpoint of administrators and students in virtual education centers about the virtual library, its role and resources. Methods: This study was a descriptive survey. The research instrument was a researcher made questionnaire that its validity and reliability was confirmed. The study population consisted of 19 virtual training centers in Tehran city. Out of 19 centers, simple randomized sampling was done in five Centers. The sample size was 360 students. Data collection was conducted online and descriptive statistics using SPSS 18 and Excel software were used. Results: The results showed that viewpoints of administrators and students about the mission and services of virtual libraries in some cases were similar and in some cases were different. One of the administrators’ reasons for setting up a virtual learning system was lifelong learning, and lack of knowledge about virtual libraries was the reason for inadequate use of virtual libraries. The best format of virtual library from the administrators’ and students’ viewpoint, was portal document format (PDF. Conclusion: One of the most important function of a virtual library, is lifelong learning and empowering users to provide information and educational needs. The main reason for not setting up a virtual library is t lack of knowledge about it.

  16. Entropy, color, and color rendering.

    Science.gov (United States)

    Price, Luke L A

    2012-12-01

    The Shannon entropy [Bell Syst. Tech J.27, 379 (1948)] of spectral distributions is applied to the problem of color rendering. With this novel approach, calculations for visual white entropy, spectral entropy, and color rendering are proposed, indices that are unreliant on the subjectivity inherent in reference spectra and color samples. The indices are tested against real lamp spectra, showing a simple and robust system for color rendering assessment. The discussion considers potential roles for white entropy in several areas of color theory and psychophysics and nonextensive entropy generalizations of the entropy indices in mathematical color spaces.

  17. Capturing, processing, and rendering real-world scenes

    Science.gov (United States)

    Nyland, Lars S.; Lastra, Anselmo A.; McAllister, David K.; Popescu, Voicu; McCue, Chris; Fuchs, Henry

    2000-12-01

    While photographs vividly capture a scene from a single viewpoint, it is our goal to capture a scene in such a way that a viewer can freely move to any viewpoint, just as he or she would in an actual scene. We have built a prototype system to quickly digitize a scene using a laser rangefinder and a high-resolution digital camera that accurately captures a panorama of high-resolution range and color information. With real-world scenes, we have provided data to fuel research in many area, including representation, registration, data fusion, polygonization, rendering, simplification, and reillumination. The real-world scene data can be used for many purposes, including immersive environments, immersive training, re-engineering and engineering verification, renovation, crime-scene and accident capture and reconstruction, archaeology and historic preservation, sports and entertainment, surveillance, remote tourism and remote sales. We will describe our acquisition system, the necessary processing to merge data from the multiple input devices and positions. We will also describe high quality rendering using the data we have collected. Issues about specific rendering accelerators and algorithms will also be presented. We will conclude by describing future uses and methods of collection for real- world scene data.

  18. Exposure render: an interactive photo-realistic volume rendering framework.

    Directory of Open Access Journals (Sweden)

    Thomas Kroes

    Full Text Available The field of volume visualization has undergone rapid development during the past years, both due to advances in suitable computing hardware and due to the increasing availability of large volume datasets. Recent work has focused on increasing the visual realism in Direct Volume Rendering (DVR by integrating a number of visually plausible but often effect-specific rendering techniques, for instance modeling of light occlusion and depth of field. Besides yielding more attractive renderings, especially the more realistic lighting has a positive effect on perceptual tasks. Although these new rendering techniques yield impressive results, they exhibit limitations in terms of their exibility and their performance. Monte Carlo ray tracing (MCRT, coupled with physically based light transport, is the de-facto standard for synthesizing highly realistic images in the graphics domain, although usually not from volumetric data. Due to the stochastic sampling of MCRT algorithms, numerous effects can be achieved in a relatively straight-forward fashion. For this reason, we have developed a practical framework that applies MCRT techniques also to direct volume rendering (DVR. With this work, we demonstrate that a host of realistic effects, including physically based lighting, can be simulated in a generic and flexible fashion, leading to interactive DVR with improved realism. In the hope that this improved approach to DVR will see more use in practice, we have made available our framework under a permissive open source license.

  19. Adaptive image contrast enhancement algorithm for point-based rendering

    Science.gov (United States)

    Xu, Shaoping; Liu, Xiaoping P.

    2015-03-01

    Surgical simulation is a major application in computer graphics and virtual reality, and most of the existing work indicates that interactive real-time cutting simulation of soft tissue is a fundamental but challenging research problem in virtual surgery simulation systems. More specifically, it is difficult to achieve a fast enough graphic update rate (at least 30 Hz) on commodity PC hardware by utilizing traditional triangle-based rendering algorithms. In recent years, point-based rendering (PBR) has been shown to offer the potential to outperform the traditional triangle-based rendering in speed when it is applied to highly complex soft tissue cutting models. Nevertheless, the PBR algorithms are still limited in visual quality due to inherent contrast distortion. We propose an adaptive image contrast enhancement algorithm as a postprocessing module for PBR, providing high visual rendering quality as well as acceptable rendering efficiency. Our approach is based on a perceptible image quality technique with automatic parameter selection, resulting in a visual quality comparable to existing conventional PBR algorithms. Experimental results show that our adaptive image contrast enhancement algorithm produces encouraging results both visually and numerically compared to representative algorithms, and experiments conducted on the latest hardware demonstrate that the proposed PBR framework with the postprocessing module is superior to the conventional PBR algorithm and that the proposed contrast enhancement algorithm can be utilized in (or compatible with) various variants of the conventional PBR algorithm.

  20. Immersive volume rendering of blood vessels

    Science.gov (United States)

    Long, Gregory; Kim, Han Suk; Marsden, Alison; Bazilevs, Yuri; Schulze, Jürgen P.

    2012-03-01

    In this paper, we present a novel method of visualizing flow in blood vessels. Our approach reads unstructured tetrahedral data, resamples it, and uses slice based 3D texture volume rendering. Due to the sparse structure of blood vessels, we utilize an octree to efficiently store the resampled data by discarding empty regions of the volume. We use animation to convey time series data, wireframe surface to give structure, and utilize the StarCAVE, a 3D virtual reality environment, to add a fully immersive element to the visualization. Our tool has great value in interdisciplinary work, helping scientists collaborate with clinicians, by improving the understanding of blood flow simulations. Full immersion in the flow field allows for a more intuitive understanding of the flow phenomena, and can be a great help to medical experts for treatment planning.

  1. RenderMan design principles

    Science.gov (United States)

    Apodaca, Tony; Porter, Tom

    1989-01-01

    The two worlds of interactive graphics and realistic graphics have remained separate. Fast graphics hardware runs simple algorithms and generates simple looking images. Photorealistic image synthesis software runs slowly on large expensive computers. The time has come for these two branches of computer graphics to merge. The speed and expense of graphics hardware is no longer the barrier to the wide acceptance of photorealism. There is every reason to believe that high quality image synthesis will become a standard capability of every graphics machine, from superworkstation to personal computer. The significant barrier has been the lack of a common language, an agreed-upon set of terms and conditions, for 3-D modeling systems to talk to 3-D rendering systems for computing an accurate rendition of that scene. Pixar has introduced RenderMan to serve as that common language. RenderMan, specifically the extensibility it offers in shading calculations, is discussed.

  2. Performance Assessment of Three Rendering Engines in 3D Computer Graphics Software

    Directory of Open Access Journals (Sweden)

    Žan Vidmar

    2015-03-01

    Full Text Available The aim of the research was the determination of testing conditions and visual and numerical evaluation of renderings made with three different rendering engines in Maya software, which is widely used for educational and computer art purposes. In the theoretical part the overview of light phenomena and their simulation in virtual space is presented. This is followed by a detailed presentation of the main rendering methods and the results and limitations of their applications to 3D objects. At the end of the theoretical part the importance of a proper testing scene and especially the role of Cornell box are explained. In the experimental part the terms and conditions as well as hardware and software used for the research are presented. This is followed by a description of the procedures, where we focused on the rendering quality and time, which enabled the comparison of settings of different render engines and determination of conditions for further rendering of testing scenes. The experimental part continued with rendering a variety of simple virtual scenes including Cornell box and virtual object with different materials and colours. Apart from visual evaluation, which was the starting point for comparison of renderings, a procedure for numerical estimation and colour deviations of renderings using the selected regions of interest in the final images is presented.

  3. Exposure Render: An Interactive Photo-Realistic Volume Rendering Framework

    NARCIS (Netherlands)

    Kroes, T.; Post, F.H.; Botha, C.P.

    2012-01-01

    The field of volume visualization has undergone rapid development during the past years, both due to advances in suitable computing hardware and due to the increasing availability of large volume datasets. Recent work has focused on increasing the visual realism in Direct Volume Rendering (DVR) by i

  4. Viewpoint Manifolds for Action Recognition

    Directory of Open Access Journals (Sweden)

    Souvenir Richard

    2009-01-01

    Full Text Available Abstract Action recognition from video is a problem that has many important applications to human motion analysis. In real-world settings, the viewpoint of the camera cannot always be fixed relative to the subject, so view-invariant action recognition methods are needed. Previous view-invariant methods use multiple cameras in both the training and testing phases of action recognition or require storing many examples of a single action from multiple viewpoints. In this paper, we present a framework for learning a compact representation of primitive actions (e.g., walk, punch, kick, sit that can be used for video obtained from a single camera for simultaneous action recognition and viewpoint estimation. Using our method, which models the low-dimensional structure of these actions relative to viewpoint, we show recognition rates on a publicly available dataset previously only achieved using multiple simultaneous views.

  5. Viewpoint Manifolds for Action Recognition

    Directory of Open Access Journals (Sweden)

    Richard Souvenir

    2009-01-01

    Full Text Available Action recognition from video is a problem that has many important applications to human motion analysis. In real-world settings, the viewpoint of the camera cannot always be fixed relative to the subject, so view-invariant action recognition methods are needed. Previous view-invariant methods use multiple cameras in both the training and testing phases of action recognition or require storing many examples of a single action from multiple viewpoints. In this paper, we present a framework for learning a compact representation of primitive actions (e.g., walk, punch, kick, sit that can be used for video obtained from a single camera for simultaneous action recognition and viewpoint estimation. Using our method, which models the low-dimensional structure of these actions relative to viewpoint, we show recognition rates on a publicly available dataset previously only achieved using multiple simultaneous views.

  6. Spatial sound rendering of a playing xylophone for the telepresence application

    DEFF Research Database (Denmark)

    Markovic, Milos; Madsen, Esben; Hoffmann, Pablo F.

    2013-01-01

    xylophone sound rendering is proposed. The recorded signal is processed in order to define multiple virtual sources which are spatially distributed for the auditory width representation of the virtual xylophone. The results of the analyzed recording and rendering techniques are compared in terms...... played at the student's location is required at the teacher’s site. This paper presents a comparison of different recording techniques for a spatial xylophone sound rendering, focusing on the horizontal width of the xylophone auditory image. The directivity pattern of the xylophone was measured...

  7. Democratizing rendering for multiple viewers in surround VR systems

    KAUST Repository

    Schulze, Jürgen P.

    2012-03-01

    We present a new approach for how multiple users\\' views can be rendered in a surround virtual environment without using special multi-view hardware. It is based on the idea that different parts of the screen are often viewed by different users, so that they can be rendered from their own view point, or at least from a point closer to their view point than traditionally expected. The vast majority of 3D virtual reality systems are designed for one head-tracked user, and a number of passive viewers. Only the head tracked user gets to see the correct view of the scene, everybody else sees a distorted image. We reduce this problem by algorithmically democratizing the rendering view point among all tracked users. Researchers have proposed solutions for multiple tracked users, but most of them require major changes to the display hardware of the VR system, such as additional projectors or custom VR glasses. Our approach does not require additional hardware, except the ability to track each participating user. We propose three versions of our multi-viewer algorithm. Each of them balances image distortion and frame rate in different ways, making them more or less suitable for certain application scenarios. Our most sophisticated algorithm renders each pixel from its own, optimized camera perspective, which depends on all tracked users\\' head positions and orientations. © 2012 IEEE.

  8. Study on Human-Computer Interaction in Immersive Virtual Environment

    Institute of Scientific and Technical Information of China (English)

    段红; 黄柯棣

    2002-01-01

    Human-computer interaction is one of the most important issues in research of Virtual Environments. This paper introduces interaction software developed for a virtual operating environment for space experiments. Core components of the interaction software are: an object-oriented database for behavior management of virtual objects, a software agent called virtual eye for viewpoint control, and a software agent called virtual hand for object manipulation. Based on the above components, some instance programs for object manipulation have been developed. The user can observe the virtual environment through head-mounted display system, control viewpoint by head tracker and/or keyboard, and select and manipulate virtual objects by 3D mouse.

  9. A virtual universe utilizing haptic display

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, T. [Sandia National Labs., Albuquerque, NM (United States)][New Mexico Univ., Albuquerque, NM (United States). Dept. of Electrical and Computer Engineering

    1996-12-31

    This paper summarizes a virtual reality universe application in which a user can travel between four virtual worlds through the use of haptic buttons. Each of the worlds demonstrates different aspects of haptic rendering which together create a wide base for force feedback effects. Specifics of the rendering algorithms will be discussed along with possible uses and modifications for other real-life applications.

  10. Direct Visuo-Haptic 4D Volume Rendering Using Respiratory Motion Models.

    Science.gov (United States)

    Fortmeier, Dirk; Wilms, Matthias; Mastmeyer, Andre; Handels, Heinz

    2015-01-01

    This article presents methods for direct visuo-haptic 4D volume rendering of virtual patient models under respiratory motion. Breathing models are computed based on patient-specific 4D CT image data sequences. Virtual patient models are visualized in real-time by ray casting based rendering of a reference CT image warped by a time-variant displacement field, which is computed using the motion models at run-time. Furthermore, haptic interaction with the animated virtual patient models is provided by using the displacements computed at high rendering rates to translate the position of the haptic device into the space of the reference CT image. This concept is applied to virtual palpation and the haptic simulation of insertion of a virtual bendable needle. To this aim, different motion models that are applicable in real-time are presented and the methods are integrated into a needle puncture training simulation framework, which can be used for simulated biopsy or vessel puncture in the liver. To confirm real-time applicability, a performance analysis of the resulting framework is given. It is shown that the presented methods achieve mean update rates around 2,000 Hz for haptic simulation and interactive frame rates for volume rendering and thus are well suited for visuo-haptic rendering of virtual patients under respiratory motion.

  11. MULTI-EPIPOLAR LINES MATCHING-BASED RAY-SPACE INTERPOLATION FOR FREE VIEWPOINT VIDEO SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Fan Liangzhong; Jiang Gangyi; Yu Mei; Yong-deak Kim

    2008-01-01

    Ray-space based arbitrary viewpoint rendering without complex object segmentation or model construction is the main technology to realize Free Viewpoint Video(FVV) system for complex scenes.Ray-space interpolation and compression are two key techniques for the solution.In this paper,correlation among multiple epipolar lines in ray-space data is analyzed,and a new method of ray-space interpolation with multi-epipolar lines matching is proposed.Comparing with the pixel-based matching interpolation method and the block-based matching interpolation method,the proposed method can achieve higher Peak Signal to Noise Ratio(PSNR)in interpolating rayspace data and rendering arbitrary viewpoint images.

  12. GPU Pro advanced rendering techniques

    CERN Document Server

    Engel, Wolfgang

    2010-01-01

    This book covers essential tools and techniques for programming the graphics processing unit. Brought to you by Wolfgang Engel and the same team of editors who made the ShaderX series a success, this volume covers advanced rendering techniques, engine design, GPGPU techniques, related mathematical techniques, and game postmortems. A special emphasis is placed on handheld programming to account for the increased importance of graphics on mobile devices, especially the iPhone and iPod touch.Example programs and source code can be downloaded from the book's CRC Press web page. 

  13. Illegal Immigration. Opposing Viewpoints Series.

    Science.gov (United States)

    Cozic, Charles P., Ed.

    Books in the Opposing Viewpoints Series present debates about current issues that can be used to teach critical reading and thinking skills. The variety of opinions expressed in this collection of articles and book excerpts explore many aspects of illegal immigration. Contrary depictions of the aspirations and attitudes of illegal immigrants fuel…

  14. Age, Health and Attractiveness Perception of Virtual (Rendered) Human Hair

    OpenAIRE

    Fink, Bernhard; Hufschmidt, Carla; Hirn, Thomas; Will, Susanne; McKelvey, Graham; Lankhof, John

    2016-01-01

    The social significance of physical appearance and beauty has been documented in many studies. It is known that even subtle manipulations of facial morphology and skin condition can alter people’s perception of a person’s age, health and attractiveness. While the variation in facial morphology and skin condition cues has been studied quite extensively, comparably little is known on the effect of hair on social perception. This has been partly caused by the technical difficulty of creating app...

  15. Real-time graphics rendering engine

    CERN Document Server

    Bao, Hujun

    2011-01-01

    ""Real-Time Graphics Rendering Engine"" reveals the software architecture of the modern real-time 3D graphics rendering engine and the relevant technologies based on the authors' experience developing this high-performance, real-time system. The relevant knowledge about real-time graphics rendering such as the rendering pipeline, the visual appearance and shading and lighting models are also introduced. This book is intended to offer well-founded guidance for researchers and developers who are interested in building their own rendering engines. Hujun Bao is a professor at the State Key Lab of

  16. Hardware Accelerated Point Rendering of Isosurfaces

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas; Christensen, Niels Jørgen

    2003-01-01

    an approximate technique for point scaling using distance attenuation which makes it possible to render points stored in display lists or vertex arrays. This enables us to render points quickly using OpenGL. Our comparisons show that point generation is significantly faster than triangle generation...... and that the advantage of rendering points as opposed to triangles increases with the size and complexity of the volumes. To gauge the visual quality of future hardware accelerated point rendering schemes, we have implemented a software based point rendering method and compare the quality to both MC and our OpenGL based...

  17. Consistency in multi-viewpoint architectural design

    NARCIS (Netherlands)

    Dijkman, R.M.; Dijkman, Remco Matthijs

    2006-01-01

    This thesis presents a framework that aids in preserving consistency in multi-viewpoint designs. In a multi-viewpoint design each stakeholder constructs his own design part. We call each stakeholder’s design part the view of that stakeholder. To construct his view, a stakeholder has a viewpoint.

  18. Consistency in multi-viewpoint architectural design

    NARCIS (Netherlands)

    Dijkman, Remco Matthijs

    2006-01-01

    This thesis presents a framework that aids in preserving consistency in multi-viewpoint designs. In a multi-viewpoint design each stakeholder constructs his own design part. We call each stakeholder¿s design part the view of that stakeholder. To construct his view, a stakeholder has a viewpoint. Thi

  19. Viewpoint

    African Journals Online (AJOL)

    4carolinebell@gmail.com

    Natural resource management (NRM) education has the potential to improve ... Using Bernstein's concepts of classification and his theories on recontextualisation, ... overall only 9% of all the knowledge statements analysed had a strong link ...

  20. Viewpoint

    African Journals Online (AJOL)

    4carolinebell@gmail.com

    feminist writing was employing 'environment' matter-of-factly in the sense of ... One wonders at the strength of the cultural stranglehold that leads states ... Advancing gender equity, through reversing the various social and economic handicaps ... An extreme example of this is the system of gender quotas in certain 'job ...

  1. Viewpoint

    African Journals Online (AJOL)

    4carolinebell@gmail.com

    There are problems with seeing the discourse and practice of educators as .... reality, the truth of transformative teaching methodologies would largely have been ignored. .... inspired by Norman Fairclough's critical realist discourse analysis.

  2. Viewpoint

    African Journals Online (AJOL)

    new capacities for adaptation and resilience in southern African. There is .... women affairs for which affirmative action is required. • It is rigorous in ... Life is not a race, it's a journey Life is a journey to be taken one step at a time and not to be.

  3. Viewpoint

    African Journals Online (AJOL)

    have to be strategic and, if it is your first time, you need to give at least three days to get your bearings'. He also ... The day was volcanic. you might have heard about the Danish proposal. ...... There were beautiful slide exhibitions and tastings ...

  4. Viewpoint

    African Journals Online (AJOL)

    economy, urbanisation and our ecological life support systems. ... for interdisciplinary approaches and for building bridges that link the university's fragmented .... In this context the term 'resilience' is appearing more frequently ... Adaptation planning for climate change will need to rely on an emerging interdisciplinary.

  5. Viewpoint

    African Journals Online (AJOL)

    Jannie Pretorius and Okkie Combrinck, University of the Free State; and Stephan du Toit, ..... pleasures of playing video games or listening to fugues derive from instinctive processes that were in place tens of ... to our teenagers today? Note.

  6. Viewpoint

    African Journals Online (AJOL)

    Jenny

    We explore, more specifically, the public relations strategies used by large corporations, and the .... Corporate PR Strategies, Richter cites an opinion on the role of public relations, made by ..... Website address: http://www.thecornerhouse.

  7. Viewpoint

    African Journals Online (AJOL)

    be to actively involve learners and to guide them in developing a deep ... opportunity which LO policy statements provide to include real-life contextual environmental .... There are given time frames in which to cover the course material on social and .... The South African schooling system is divided into four phases: the ...

  8. Viewpoint

    African Journals Online (AJOL)

    Sustainable Development: A Cross-cultural Approach for ... whilst at the same time projecting a globally shared perspective on the topic. ... the school and consider its impact on the quality of soil and water in the surrounding area, and.

  9. Viewpoint

    African Journals Online (AJOL)

    Jenny

    2004 Environmental Education Association of Southern Africa. There seems to be an emerging dislocation in views on environment. This is manifesting in a tendency to separate out the social from the biophysical and ... initiatives which taught about nature and ecosystems as if people and ..... ultimate route to happiness.

  10. Viewpoint

    African Journals Online (AJOL)

    diversity such as poverty, inequality, race, gender, language, age, disability and other ... protecting non-union immigrants and undocumented workers; .... inclusion of environmental justice into one of these key principles of the ... 120 publications to his credit and serves on several editorial boards of peer-reviewed journals.

  11. Viewpoint

    African Journals Online (AJOL)

    in the study were 36 first-year students registered for a module on Ecology. ... The methodological approach to this study was interpretive as it attempted to interpret ..... Analysis of the students' responses show that the majority of students ... 5%. 95%. Would your marks have been higher if you had done fieldwork at school?

  12. Viewpoint

    African Journals Online (AJOL)

    Sheperd Urenje, University of London, Uk ... study design employed a qualitative methodology using a mixed methods approach of document ... which comprise a learning space for sustainable development by enabling social learning in the.

  13. The diagnostic contribution of CT volumetric rendering techniques in routine practice

    OpenAIRE

    Perandini Simone; Faccioli N; Zaccarella A; Re T; Mucelli R

    2010-01-01

    Computed tomography (CT) volumetric rendering techniques such as maximum intensity projection (MIP), minimum intensity projection (MinIP), shaded surface display (SSD), volume rendering (VR), and virtual endoscopy (VE) provide added diagnostic capabilities. The diagnostic value of such reconstruction techniques is well documented in literature. These techniques permit the exploration of fine anatomical detail that would be difficult to evaluate using axial reconstructions alone. Although thes...

  14. Cluster parallel rendering based on encoded mesh

    Institute of Scientific and Technical Information of China (English)

    QIN Ai-hong; XIONG Hua; PENG Hao-yu; LIU Zhen; SHI Jiao-ying

    2006-01-01

    Use of compressed mesh in parallel rendering architecture is still an unexplored area, the main challenge of which is to partition and sort the encoded mesh in compression-domain. This paper presents a mesh compression scheme PRMC (Parallel Rendering based Mesh Compression) supplying encoded meshes that can be partitioned and sorted in parallel rendering system even in encoded-domain. First, we segment the mesh into submeshes and clip the submeshes' boundary into Runs, and then piecewise compress the submeshes and Runs respectively. With the help of several auxiliary index tables, compressed submeshes and Runs can serve as rendering primitives in parallel rendering system. Based on PRMC, we design and implement a parallel rendering architecture. Compared with uncompressed representation, experimental results showed that PRMC meshes applied in cluster parallel rendering system can dramatically reduce the communication requirement.

  15. A survey on hair modeling: styling, simulation, and rendering.

    Science.gov (United States)

    Ward, Kelly; Bertails, Florence; Kim, Tae-Yong; Marschner, Stephen R; Cani, Marie-Paule; Lin, Ming C

    2007-01-01

    Realistic hair modeling is a fundamental part of creating virtual humans in computer graphics. This paper surveys the state of the art in the major topics of hair modeling: hairstyling, hair simulation, and hair rendering. Because of the difficult, often unsolved problems that arise in all these areas, a broad diversity of approaches are used, each with strengths that make it appropriate for particular applications. We discuss each of these major topics in turn, presenting the unique challenges facing each area and describing solutions that have been presented over the years to handle these complex issues. Finally, we outline some of the remaining computational challenges in hair modeling.

  16. Those are your legs: The effect of visuo-spatial viewpoint on visuo-tactile integration and body ownership

    Directory of Open Access Journals (Sweden)

    Polona ePozeg

    2015-11-01

    Full Text Available Experiencing a body part as one’s own, i.e. body ownership, depends on the integration of multisensory bodily signals (including visual, tactile, and proprioceptive information with the visual top-down signals from peripersonal space. Although it has been shown that the visuo-spatial viewpoint from where the body is seen is an important visual top-down factor for body ownership, different studies have reported diverging results. Furthermore, the role of visuo-spatial viewpoint (sometime also called first-person perspective has only been studied for hands or the whole body, but not for the lower limbs. We thus investigated whether and how leg visuo-tactile integration and leg ownership depended on the visuo-spatial viewpoint from which the legs were seen and the anatomical similarity of the visual leg stimuli. Using a virtual leg illusion, we tested the strength of visuo-tactile integration of leg stimuli using the cross-modal congruency effect (CCE as well as the subjective sense of leg ownership (assessed by a questionnaire. Fifteen participants viewed virtual legs or non-corporeal control objects, presented either from their habitual first-person viewpoint or from a viewpoint that was rotated by 90° (third-person viewpoint, while applying visuo-tactile stroking between the participants legs and the virtual legs shown on a head-mounted display. The data show that the first-person visuo-spatial viewpoint significantly boosts the visuo-tactile integration as well as the sense of leg ownership. Moreover, the viewpoint-dependent increment of the visuo-tactile integration was only found in the conditions when participants viewed the virtual legs (absent for control objects. These results confirm the importance of first person visuo-spatial viewpoint for the integration of visuo-tactile stimuli and extend findings from the upper extremity and the trunk to visuo-tactile integration and ownership for the legs.

  17. Rendering Caustics on Non-Lambertian Surfaces

    DEFF Research Database (Denmark)

    Jensen, Henrik Wann

    1997-01-01

    This paper presents a new technique for rendering caustics on non-Lambertian surfaces. The method is based on an extension of the photon map which removes previous restrictions limiting the usage to Lambertian surfaces. We add information about the incoming direction to the photons and this allow...... reduces the rendering time. We have used the method to render caustics on surfaces with reflectance functions varying from Lambertian to glossy specular....

  18. Building Interstellar's black hole: the gravitational renderer

    OpenAIRE

    James, Oliver; Dieckmann, Sylvan; Pabst, Simon; Roberts, Paul-George H.; Thorne, Kip S.

    2015-01-01

    Interstellar is the first feature film to attempt depicting a black hole as it would actually be seen by somebody nearby. A close collaboration between the production's Scientific Advisor and the Visual Effects team led to the development of a new renderer, DNGR (Double Negative Gravitational Renderer) which uses novel techniques for rendering in curved space-time. Following the completion of the movie, the code was adapted for scientific research, leading to new insights into gravitational l...

  19. Image Based Rendering under Varying Illumination

    Institute of Scientific and Technical Information of China (English)

    Wang Chengfeng (王城峰); Hu Zhanyi

    2003-01-01

    A new approach for photorealistic rendering of a class of objects at arbitrary illumination is presented. The approach of the authors relies entirely on image based rendering techniques. A scheme is utilized for re-illumination of objects based on linear combination of low dimensional image representations. The minimum rendering condition of technique of the authors is three sample images under varying illumination of a reference object and a single input image of an interested object. Important properties of this approach are its simplicity, robustness and speediness. Experimental results validate the proposed rendering approach.

  20. RenderToolbox3: MATLAB tools that facilitate physically based stimulus rendering for vision research.

    Science.gov (United States)

    Heasly, Benjamin S; Cottaris, Nicolas P; Lichtman, Daniel P; Xiao, Bei; Brainard, David H

    2014-02-07

    RenderToolbox3 provides MATLAB utilities and prescribes a workflow that should be useful to researchers who want to employ graphics in the study of vision and perhaps in other endeavors as well. In particular, RenderToolbox3 facilitates rendering scene families in which various scene attributes and renderer behaviors are manipulated parametrically, enables spectral specification of object reflectance and illuminant spectra, enables the use of physically based material specifications, helps validate renderer output, and converts renderer output to physical units of radiance. This paper describes the design and functionality of the toolbox and discusses several examples that demonstrate its use. We have designed RenderToolbox3 to be portable across computer hardware and operating systems and to be free and open source (except for MATLAB itself). RenderToolbox3 is available at https://github.com/DavidBrainard/RenderToolbox3.

  1. Black Holes: The Membrane Viewpoint

    Science.gov (United States)

    Thorne, Kip S.

    Contents: I. Introduction: 1. Overview of the membrane viewpoint. 2. History of research on the membrane viewpoint. II. The 3+1 split of spacetime: 1. ZAMOs and the 3+1 split of the metric. 2. Gravitoelectric and gravitomagnetic fields. 3. 3+1 split of electrodynamics. III. Stretching the horizon and black-hole thermodynamics: 1. Macdonald's vibrating magnetic field problem. 2. Stretching the horizon. 3. The entropy of a black hole. 4. The thermodynamics and mechanics of a black hole. IV. Electrodynamics of the stretched horizon: 1. The laws of Gauss, Ampere, Ohm, and charge conservation. 2. Lorentz force and ohmic dissipation in the stretched horizon. V. Some electromagnetic model problems: 1. Charge separation in the stretched horizon. 2. Black hole as a resistor in an electric circuit. 3. Black hole as the rotor in an electric motor. 4. Rotating hole immersed in a time-independent, vacuum magnetic field. 5. Magnetized, rotating hole as a battery for an external circuit. VI. Astrophysical applications of the membrane formalism. VII. Conclusion.

  2. Physically based rendering: from theory to implementation

    National Research Council Canada - National Science Library

    Pharr, Matt; Humphreys, Greg, Ph. D

    2010-01-01

    ... rendering algorithm variations. This book is not only a textbook for students, but also a useful reference book for practitioners in the field. The second edition has been extended with sections on Metropolis light transport, subsurface scattering, precomputed light transport, and more. Per Christensen Senior Software Developer, RenderMan Products,...

  3. Multiple Viewpoints System/ Software Engineering for Space

    Science.gov (United States)

    Blondelle, Gael; Panunzio, Marco; Pequery, Jerome; Bats, Melanie; Garcia, Gerald; Brun, Cedric

    2013-08-01

    This paper presents a return of experience on using viewpoint-oriented modeling to design on-board software for satellites. First, we demonstrate the interest of integrating heterogeneous viewpoints in a tool to cover the development process of an embedded system. Then, we recall the Space Component Model, its implementation with Obeo Designer, and the capability to extend it with specific purpose Domain Specific Languages. Last, we expose further viewpoints that could be implemented to address new aspects like safety or interoperability.

  4. Moisture movements in render on brick wall

    DEFF Research Database (Denmark)

    Hansen, Kurt Kielsgaard; Munch, Thomas Astrup; Thorsen, Peter Schjørmann

    2003-01-01

    A three-layer render on brick wall used for building facades is studied in the laboratory. The vertical render surface is held in contact with water for 24 hours simulating driving rain while it is measured with non-destructive X-ray equipment every hour in order to follow the moisture front...... through the render and into the brick. The test specimen is placed between the source and the detector. The test specimens are all scanned before they are exposed to water. In that way the loss of counts from the dry scan to the wet scan qualitatively shows the presence of water. The results show nearly...... no penetration of water through the render and into the brick, and the results are independent of the start condition of the test specimens. Also drying experiments are performed. The results show a small difference in the rate of drying, in favour of the bricks without render....

  5. Physically based rendering from theory to implementation

    CERN Document Server

    Pharr, Matt

    2010-01-01

    "Physically Based Rendering, 2nd Edition" describes both the mathematical theory behind a modern photorealistic rendering system as well as its practical implementation. A method - known as 'literate programming'- combines human-readable documentation and source code into a single reference that is specifically designed to aid comprehension. The result is a stunning achievement in graphics education. Through the ideas and software in this book, you will learn to design and employ a full-featured rendering system for creating stunning imagery. This book features new sections on subsurface scattering, Metropolis light transport, precomputed light transport, multispectral rendering, and much more. It includes a companion site complete with source code for the rendering system described in the book, with support for Windows, OS X, and Linux. Code and text are tightly woven together through a unique indexing feature that lists each function, variable, and method on the page that they are first described.

  6. Spatial sound rendering of a playing xylophone for the telepresence application

    DEFF Research Database (Denmark)

    Markovic, Milos; Madsen, Esben; Hoffmann, Pablo F.

    2013-01-01

    and spatial properties of the sound field created by a xylophone as a distributed sound source were analyzed. Xylophone recordings were performed using different microphone configurations: one and two-channel recording setups are implemented. One-channel recording technique with binaural synthesis for spatial...... played at the student's location is required at the teacher’s site. This paper presents a comparison of different recording techniques for a spatial xylophone sound rendering, focusing on the horizontal width of the xylophone auditory image. The directivity pattern of the xylophone was measured...... xylophone sound rendering is proposed. The recorded signal is processed in order to define multiple virtual sources which are spatially distributed for the auditory width representation of the virtual xylophone. The results of the analyzed recording and rendering techniques are compared in terms...

  7. Construction and Evaluation of an Ultra Low Latency Frameless Renderer for VR.

    Science.gov (United States)

    Friston, Sebastian; Steed, Anthony; Tilbury, Simon; Gaydadjiev, Georgi

    2016-04-01

    Latency - the delay between a user's action and the response to this action - is known to be detrimental to virtual reality. Latency is typically considered to be a discrete value characterising a delay, constant in time and space - but this characterisation is incomplete. Latency changes across the display during scan-out, and how it does so is dependent on the rendering approach used. In this study, we present an ultra-low latency real-time ray-casting renderer for virtual reality, implemented on an FPGA. Our renderer has a latency of ~1 ms from 'tracker to pixel'. Its frameless nature means that the region of the display with the lowest latency immediately follows the scan-beam. This is in contrast to frame-based systems such as those using typical GPUs, for which the latency increases as scan-out proceeds. Using a series of high and low speed videos of our system in use, we confirm its latency of ~1 ms. We examine how the renderer performs when driving a traditional sequential scan-out display on a readily available HMO, the Oculus Rift OK2. We contrast this with an equivalent apparatus built using a GPU. Using captured human head motion and a set of image quality measures, we assess the ability of these systems to faithfully recreate the stimuli of an ideal virtual reality system - one with a zero latency tracker, renderer and display running at 1 kHz. Finally, we examine the results of these quality measures, and how each rendering approach is affected by velocity of movement and display persistence. We find that our system, with a lower average latency, can more faithfully draw what the ideal virtual reality system would. Further, we find that with low display persistence, the sensitivity to velocity of both systems is lowered, but that it is much lower for ours.

  8. 3D Rendering - Techniques and Challenges

    Directory of Open Access Journals (Sweden)

    Ekta Walia

    2010-04-01

    Full Text Available Computer generated images and animations are getting more and more common. They are used in many different contexts such as movies,mobiles, medical visualization, architectural visualization and CAD. Advanced ways of describing surface and light source properties are important to ensure that artists are able to create realistic and stylish looking images. Even when using advanced rendering algorithms such as ray tracing, time required for shading may contribute towards a large part of the image creation time. Therefore both performance and flexibility is important in a rendering system. This paper gives a comparative study of various 3D Rendering techniques and their challenges in a complete and systematic manner.

  9. A point-based rendering approach for real-time interaction on mobile devices

    Institute of Scientific and Technical Information of China (English)

    LIANG XiaoHui; ZHAO QinPing; HE ZhiYing; XIE Ke; LIU YuBo

    2009-01-01

    Mobile device is an Important interactive platform. Due to the limitation of computation, memory, display area and energy, how to realize the efficient and real-time interaction of 3D models based on mobile devices is an important research topic. Considering features of mobile devices, this paper adopts remote rendering mode and point models, and then, proposes a transmission and rendering approach that could interact in real time. First, improved simplification algorithm based on MLS and display resolution of mobile devices is proposed. Then, a hierarchy selection of point models and a QoS transmission control strategy are given based on interest area of operator, interest degree of object in the virtual environment and rendering error. They can save the energy consumption. Finally, the rendering and interaction of point models are completed on mobile devices. The experiments show that our method is efficient.

  10. On Abstraction Levels For Software Architecture Viewpoints

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun

    2005-01-01

    abstraction levels defined in this paper, viewpoints can be described more accurately and applied more consistently. This can help developers easier gain proficiency in the use of viewpoints to describe software architectures of systems. In this paper concepts which clarify the relation between the defined......In the field of software architecture the abstraction level of a viewpoint has often been defined on a scale from low to high. However, the definition of abstraction levels on a scale from low to high makes it very subjective what is at each level. This makes it difficult to apply the different...... existing viewpoints in practice, because each viewpoint can be applied at many different levels of abstraction which the architect has to consider. This also makes it hard for people to enter the field of software architecture and become proficient in using its techniques and methods. By using the three...

  11. FAST CROWD RENDERING IN COMPUTER GAMES

    Directory of Open Access Journals (Sweden)

    Kaya OĞUZ

    2010-06-01

    Full Text Available Computer games, with the speed advancements of graphical processors, are coming closer to the quality of cinema industry. Contrary to offline rendering of the scenes in a motion picture, computer games should be able to render at 30 frames per second. Therefore, CPU and memory performance are sought by using various techniques. This paper is about using instancing feature of contemporary graphical processors along with level of detail techniques which has been in use for a very long time. Using instancing, 15,000 instances were successfully rendered at 30 frames per second using a very low %10 CPU usage. The application can render 40,000 instances at 13 frames per second.

  12. Visibility-Aware Direct Volume Rendering

    Institute of Scientific and Technical Information of China (English)

    Wai-Ho Mak; Yingcai Wu; Ming-Yuen Chan; Huamin Qu

    2011-01-01

    Direct volume rendering (DVR) is a powerful visualization technique which allows users to effectively explore and study volumetric datasets. Different transparency settings can be flexibly assigned to different structures such that some valuable information can be revealed in direct volume rendered images (DVRIs). However, end-users often feel that some risks are always associated with DVR because they do not know whether any important information is missing from the transparent regions of DVRIs. In this paper, we investigate how to semi-automatically generate a set of DVRIs and also an animation which can reveal information missed in the original DVRIs and meanwhile satisfy some image quality criteria such as coherence. A complete framework is developed to tackle various problems related to the generation and quality evaluation of visibility-aware DVRIs and animations. Our technique can reduce the risk of using direct volume rendering and thus boost the confidence of users in volume rendering systems.

  13. Layered Textures for Image-Based Rendering

    Institute of Scientific and Technical Information of China (English)

    en-Cheng Wang; ui-Yu Li; in Zheng; n-Hua Wu

    2004-01-01

    An extension to texture mapping is given in this paper for improving the efficiency of image-based rendering. For a depth image with an orthogonal displacement at each pixel, it is decomposed by the displacement into a series of layered textures (LTs) with each one having the same displacement for all its texels. Meanwhile,some texels of the layered textures are interpolated for obtaining a continuous 3D approximation of the model represented in the depth image. Thus, the plane-to-plane texture mapping can be used to map these layered textures to produce novel views and the advantages can be obtained as follows: accelerating the rendering speed,supporting the 3D surface details and view motion parallax, and avoiding the expensive task of hole-filling in the rendering stage. Experimental results show the new method can produce high-quality images and run faster than many famous image-based rendering techniques.

  14. Composed Scattering Model for Direct Volume Rendering

    Institute of Scientific and Technical Information of China (English)

    蔡文立; 石教英

    1996-01-01

    Based on the equation of transfer in transport theory of optical physics,a new volume rendering model,called composed scattering model(CSM),is presented.In calculating the scattering term of the equation,it is decomposed into volume scattering intensity and surface scattering intensity,and they are composed with the boundary detection operator as the weight function.This proposed model differs from the most current volume rendering models in the aspect that in CSM segmentation and illumination intensity calculation are taken as two coherent parts while in existing models they are regarded as two separate ones.This model has been applied to the direct volume rendering of 3D data sets obtained by CT and MRI.The resultant images show not only rich details but also clear boundary surfaces.CSM is demonstrated to be an accurate volume rendering model suitable for CT and MRI data sets.

  15. Latency in Distributed Acquisition and Rendering for Telepresence Systems.

    Science.gov (United States)

    Ohl, Stephan; Willert, Malte; Staadt, Oliver

    2015-12-01

    Telepresence systems use 3D techniques to create a more natural human-centered communication over long distances. This work concentrates on the analysis of latency in telepresence systems where acquisition and rendering are distributed. Keeping latency low is important to immerse users in the virtual environment. To better understand latency problems and to identify the source of such latency, we focus on the decomposition of system latency into sub-latencies. We contribute a model of latency and show how it can be used to estimate latencies in a complex telepresence dataflow network. To compare the estimates with real latencies in our prototype, we modify two common latency measurement methods. This presented methodology enables the developer to optimize the design, find implementation issues and gain deeper knowledge about specific sources of latency.

  16. Organizaciones Virtuales Organizaciones Virtuales

    Directory of Open Access Journals (Sweden)

    Gladis Cecilia Villegas Arias

    2003-06-01

    Full Text Available Virtual Organizations are new organizational forms originated from both the replacementof face to face communications by remote communications supported by electronic means,and from the accesibility of real time information about the operation of the company, forall employees.This article pursues the following goals: 1 To define virtual organization, review its sociotechnical antecedents and propose a preliminary classification into inter-organizationaland intra-organizational forms.  2 To discuss the characteristics of virtual organizationsand their impact on organizational design, and 3 To compare virtual organizations toother organizational forms.Las organizaciones virtuales son formas organizativas nuevas, que resultan de: primero, reemplazar las interacciones cara a cara con interacciones remotas, soportadas por comunicaciones electrónicas y segundo,  proveer acceso en tiempo real a toda la información de la empresa para todos los trabajadores.En este artículo se busca: 1 Definir organización virtual, revisar sus antecedentes y proponeruna clasificación básica preliminar de las mismas  2 Discutir las características de las organizaciones virtuales y sus implicaciones para el diseño organizativo 3 Comparar estaforma organizativa a las formas organizativas no virtuales.

  17. Virtually teaching virtual leadership

    DEFF Research Database (Denmark)

    Henriksen, Thomas Duus; Nielsen, Rikke Kristine; Børgesen, Kenneth

    2017-01-01

    This paper seeks to investigate the challenges to virtual collaboration and leadership on basis of findings from a virtual course on collaboration and leadership. The course used for this experiment was designed as a practical approach, which allowed participants to experience curriculum phenomen...

  18. Three-dimensional rendering of segmented object using matlab - biomed 2010.

    Science.gov (United States)

    Anderson, Jeffrey R; Barrett, Steven F

    2010-01-01

    The three-dimensional rendering of microscopic objects is a difficult and challenging task that often requires specialized image processing techniques. Previous work has been described of a semi-automatic segmentation process of fluorescently stained neurons collected as a sequence of slice images with a confocal laser scanning microscope. Once properly segmented, each individual object can be rendered and studied as a three-dimensional virtual object. This paper describes the work associated with the design and development of Matlab files to create three-dimensional images from the segmented object data previously mentioned. Part of the motivation for this work is to integrate both the segmentation and rendering processes into one software application, providing a seamless transition from the segmentation tasks to the rendering and visualization tasks. Previously these tasks were accomplished on two different computer systems, windows and Linux. This transition basically limits the usefulness of the segmentation and rendering applications to those who have both computer systems readily available. The focus of this work is to create custom Matlab image processing algorithms for object rendering and visualization, and merge these capabilities to the Matlab files that were developed especially for the image segmentation task. The completed Matlab application will contain both the segmentation and rendering processes in a single graphical user interface, or GUI. This process for rendering three-dimensional images in Matlab requires that a sequence of two-dimensional binary images, representing a cross-sectional slice of the object, be reassembled in a 3D space, and covered with a surface. Additional segmented objects can be rendered in the same 3D space. The surface properties of each object can be varied by the user to aid in the study and analysis of the objects. This inter-active process becomes a powerful visual tool to study and understand microscopic objects.

  19. Rendering and Compositing Infrastructure Improvements to VisIt for Insitu Rendering

    Energy Technology Data Exchange (ETDEWEB)

    Loring, Burlen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ruebel, Oliver [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-01-28

    Compared to posthoc rendering, insitu rendering often generates larger numbers of images, as a result rendering performance and scalability are critical in the insitu setting. In this work we present improvements to VisIt's rendering and compositing infrastructure that deliver increased performance and scalability in both posthoc and insitu settings. We added the capability for alpha blend compositing and use it with ordered compositing when datasets have disjoint block domain decomposition to optimize the rendering of transparent geometry. We also made improvements that increase overall efficiency by reducing communication and data movement and have addressed a number of performance issues. We structured our code to take advantage of SIMD parallelization and use threads to overlap communication and compositing. We tested our improvements on a 20 core workstation using 8 cores to render geometry generated from a $256^3$ cosmology dataset and on a Cray XC31 using 512 cores to render geometry generated from a $2000^2 \\times 800$ plasma dataset. Our results show that ordered compositing provides a speed up of up to $4 \\times$ over the current sort first strategy. The other improvements resulted in modest speed up with one notable exception where we achieve up to $40 \\times$ speed up of rendering and compositing of opaque geometry when both opaque and transparent geometry are rendered together. We also investigated the use of depth peeling, but found that the implementation provided by VTK is substantially slower,both with and without GPU acceleration, than a local camera order sort.

  20. Brain Image Representation and Rendering: A Survey

    Directory of Open Access Journals (Sweden)

    Mudassar Raza

    2012-09-01

    Full Text Available Brain image representation and rendering processes are basically used for evaluation, development and investigation consent experimental examination and formation of brain images of a variety of modalities that includes the major brain types like MEG, EEG, PET, MRI, CT or microscopy. So, there is a need to conduct a study to review the existing work in this area. This paper provides a review of different existing techniques and methods regarding the brain image representation and rendering. Image Rendering is the method of generating an image by means of a model, through computer programs. The basic purpose of brain image representation and rendering processes is to analyze the brain images precisely in order to effectively diagnose and examine the diseases and problems. The basic objective of this study is to evaluate and discuss different techniques and approaches proposed in order to handle different brain imaging types. The paper provides a short overview of different methods, in the form of advantages and limitations, presented in the prospect of brain image representation and rendering along with their sub categories proposed by different authors.

  1. Equalizer: a scalable parallel rendering framework.

    Science.gov (United States)

    Eilemann, Stefan; Makhinya, Maxim; Pajarola, Renato

    2009-01-01

    Continuing improvements in CPU and GPU performances as well as increasing multi-core processor and cluster-based parallelism demand for flexible and scalable parallel rendering solutions that can exploit multipipe hardware accelerated graphics. In fact, to achieve interactive visualization, scalable rendering systems are essential to cope with the rapid growth of data sets. However, parallel rendering systems are non-trivial to develop and often only application specific implementations have been proposed. The task of developing a scalable parallel rendering framework is even more difficult if it should be generic to support various types of data and visualization applications, and at the same time work efficiently on a cluster with distributed graphics cards. In this paper we introduce a novel system called Equalizer, a toolkit for scalable parallel rendering based on OpenGL which provides an application programming interface (API) to develop scalable graphics applications for a wide range of systems ranging from large distributed visualization clusters and multi-processor multipipe graphics systems to single-processor single-pipe desktop machines. We describe the system architecture, the basic API, discuss its advantages over previous approaches, present example configurations and usage scenarios as well as scalability results.

  2. Standardized rendering from IR surveillance motion imagery

    Science.gov (United States)

    Prokoski, F. J.

    2014-06-01

    Government agencies, including defense and law enforcement, increasingly make use of video from surveillance systems and camera phones owned by non-government entities.Making advanced and standardized motion imaging technology available to private and commercial users at cost-effective prices would benefit all parties. In particular, incorporating thermal infrared into commercial surveillance systems offers substantial benefits beyond night vision capability. Face rendering is a process to facilitate exploitation of thermal infrared surveillance imagery from the general area of a crime scene, to assist investigations with and without cooperating eyewitnesses. Face rendering automatically generates greyscale representations similar to police artist sketches for faces in surveillance imagery collected from proximate locations and times to a crime under investigation. Near-realtime generation of face renderings can provide law enforcement with an investigation tool to assess witness memory and credibility, and integrate reports from multiple eyewitnesses, Renderings can be quickly disseminated through social media to warn of a person who may pose an immediate threat, and to solicit the public's help in identifying possible suspects and witnesses. Renderings are pose-standardized so as to not divulge the presence and location of eyewitnesses and surveillance cameras. Incorporation of thermal infrared imaging into commercial surveillance systems will significantly improve system performance, and reduce manual review times, at an incremental cost that will continue to decrease. Benefits to criminal justice would include improved reliability of eyewitness testimony and improved accuracy of distinguishing among minority groups in eyewitness and surveillance identifications.

  3. An Image—Based Virtual Reality Prototype System

    Institute of Scientific and Technical Information of China (English)

    蔡勇; 王平安; 等

    1998-01-01

    The most important goal of virtual reality is to create a virtual world computers where users are allowed to view the environment and control the virtual objects interactively.Traditionally,virtual reality systems use 3D computer graphics to model and render a virtual environment in real time.However,this approach usually requires laborious modeling and expensive special-purpose rendering hardware.Image-based rendering is a new approach in composing a virtual environment in which a set of panoramic images is used to compose the virtual environment and walking in the space is accomplished by “hopping”to different panoramic points.This paper introduces an experimental image-based VR system.The techniques utilized in the system,in particular the authoring and interactive control tools of the system,are described in detail.

  4. Software Architecture Viewpoint Models: A Short Survey

    Directory of Open Access Journals (Sweden)

    Seyyed Ali Razavi Ebrahimi

    2013-11-01

    Full Text Available A software architecture is a complex entity that cannot be described in a simple one-dimensional fashion. The architecture views used to describe software provide the architect with a means of explaining the architecture to stakeholders. Each view presents different aspects of the system that fulfill functional and non-functional requirements. A view of a system is a representation of the system from the perspective of a viewpoint. Architecture viewpoints in software products provide guidelines to describe uniformly the total system and its subsystems. It defines the stakeholders whose concerns are reflected in the viewpoint and the guidelines, principles, and template models for constructing its views. The results of this study may serve as a roadmap to the software developers and architects in helping them select the appropriate viewpoint model based on the stakeholders and concerns that need to be covered by views.

  5. Rendering Falling Leaves on Graphics Hardware

    Directory of Open Access Journals (Sweden)

    Marcos Balsa

    2008-04-01

    Full Text Available There is a growing interest in simulating natural phenomena in computer graphics applications. Animating natural scenes in real time is one of the most challenging problems due to the inherent complexity of their structure, formed by millions of geometric entities, and the interactions that happen within. An example of natural scenario that is needed for games or simulation programs are forests. Forests are difficult to render because the huge amount of geometric entities and the large amount of detail to be represented. Moreover, the interactions between the objects (grass, leaves and external forces such as wind are complex to model. In this paper we concentrate in the rendering of falling leaves at low cost. We present a technique that exploits graphics hardware in order to render thousands of leaves with different falling paths in real time and low memory requirements.

  6. A hitchhiker's guide to virtual reality

    CERN Document Server

    McMenemy , Karen

    2007-01-01

    A Hitchhiker's Guide to Virtual Reality brings together under one cover all the aspects of graphics, video, audio, and haptics that have to work together to make virtual reality a reality. Like any good guide, it reveals the practical things you need to know, from the viewpoint of authors who have been there. This two-part guide covers the science, technology, and mathematics of virtual reality and then details its practical implementation. The first part looks at how the interface between human senses and technology works to create virtual reality, with a focus on vision, the most important s

  7. Blender cycles lighting and rendering cookbook

    CERN Document Server

    Iraci, Bernardo

    2013-01-01

    An in-depth guide full of step-by-step recipes to explore the concepts behind the usage of Cycles. Packed with illustrations, and lots of tips and tricks; the easy-to-understand nature of the book will help the reader understand even the most complex concepts with ease.If you are a digital artist who already knows your way around Blender, and you want to learn about the new Cycles' rendering engine, this is the book for you. Even experts will be able to pick up new tips and tricks to make the most of the rendering capabilities of Cycles.

  8. Volume Rendering for Curvilinear and Unstructured Grids

    Energy Technology Data Exchange (ETDEWEB)

    Max, N; Williams, P; Silva, C; Cook, R

    2003-03-05

    We discuss two volume rendering methods developed at Lawrence Livermore National Laboratory. The first, cell projection, renders the polygons in the projection of each cell. It requires a global visibility sort in order to composite the cells in back to front order, and we discuss several different algorithms for this sort. The second method uses regularly spaced slice planes perpendicular to the X, Y, or Z axes, which slice the cells into polygons. Both methods are supplemented with anti-aliasing techniques to deal with small cells that might fall between pixel samples or slice planes, and both have been parallelized.

  9. GPU Pro 5 advanced rendering techniques

    CERN Document Server

    Engel, Wolfgang

    2014-01-01

    In GPU Pro5: Advanced Rendering Techniques, section editors Wolfgang Engel, Christopher Oat, Carsten Dachsbacher, Michal Valient, Wessam Bahnassi, and Marius Bjorge have once again assembled a high-quality collection of cutting-edge techniques for advanced graphics processing unit (GPU) programming. Divided into six sections, the book covers rendering, lighting, effects in image space, mobile devices, 3D engine design, and compute. It explores rasterization of liquids, ray tracing of art assets that would otherwise be used in a rasterized engine, physically based area lights, volumetric light

  10. Digital color acquisition, perception, coding and rendering

    CERN Document Server

    Fernandez-Maloigne, Christine; Macaire, Ludovic

    2013-01-01

    In this book the authors identify the basic concepts and recent advances in the acquisition, perception, coding and rendering of color. The fundamental aspects related to the science of colorimetry in relation to physiology (the human visual system) are addressed, as are constancy and color appearance. It also addresses the more technical aspects related to sensors and the color management screen. Particular attention is paid to the notion of color rendering in computer graphics. Beyond color, the authors also look at coding, compression, protection and quality of color images and videos.

  11. Haptic rendering for simulation of fine manipulation

    CERN Document Server

    Wang, Dangxiao; Zhang, Yuru

    2014-01-01

    This book introduces the latest progress in six degrees of freedom (6-DoF) haptic rendering with the focus on a new approach for simulating force/torque feedback in performing tasks that require dexterous manipulation skills. One of the major challenges in 6-DoF haptic rendering is to resolve the conflict between high speed and high fidelity requirements, especially in simulating a tool interacting with both rigid and deformable objects in a narrow space and with fine features. The book presents a configuration-based optimization approach to tackle this challenge. Addressing a key issue in man

  12. VITRAIL: Acquisition, Modeling, and Rendering of Stained Glass.

    Science.gov (United States)

    Thanikachalam, Niranjan; Baboulaz, Loic; Prandoni, Paolo; Trumpler, Stefan; Wolf, Sophie; Vetterli, Martin

    2016-10-01

    Stained glass windows are designed to reveal their powerful artistry under diverse and time-varying lighting conditions; virtual relighting of stained glass, therefore, represents an exceptional tool for the appreciation of this age old art form. However, as opposed to most other artifacts, stained glass windows are extremely difficult if not impossible to analyze using controlled illumination because of their size and position. In this paper, we present novel methods built upon image based priors to perform virtual relighting of stained glass artwork by acquiring the actual light transport properties of a given artifact. In a preprocessing step, we build a material-dependent dictionary for light transport by studying the scattering properties of glass samples in a laboratory setup. We can now use the dictionary to recover a light transport matrix in two ways: under controlled illuminations the dictionary constitutes a sparsifying basis for a compressive sensing acquisition, while in the case of uncontrolled illuminations the dictionary is used to perform sparse regularization. The proposed basis preserves volume impurities and we show that the retrieved light transport matrix is heterogeneous, as in the case of real world objects. We present the rendering results of several stained glass artifacts, including the Rose Window of the Cathedral of Lausanne, digitized using the presented methods.

  13. Rendering Visible: Painting and Sexuate Subjectivity

    Science.gov (United States)

    Daley, Linda

    2015-01-01

    In this essay, I examine Luce Irigaray's aesthetic of sexual difference, which she develops by extrapolating from Paul Klee's idea that the role of painting is to render the non-visible rather than represent the visible. This idea is the premise of her analyses of phenomenology and psychoanalysis and their respective contributions to understanding…

  14. ProteinShader: illustrative rendering of macromolecules

    Directory of Open Access Journals (Sweden)

    Weber Joseph R

    2009-03-01

    Full Text Available Abstract Background Cartoon-style illustrative renderings of proteins can help clarify structural features that are obscured by space filling or balls and sticks style models, and recent advances in programmable graphics cards offer many new opportunities for improving illustrative renderings. Results The ProteinShader program, a new tool for macromolecular visualization, uses information from Protein Data Bank files to produce illustrative renderings of proteins that approximate what an artist might create by hand using pen and ink. A combination of Hermite and spherical linear interpolation is used to draw smooth, gradually rotating three-dimensional tubes and ribbons with a repeating pattern of texture coordinates, which allows the application of texture mapping, real-time halftoning, and smooth edge lines. This free platform-independent open-source program is written primarily in Java, but also makes extensive use of the OpenGL Shading Language to modify the graphics pipeline. Conclusion By programming to the graphics processor unit, ProteinShader is able to produce high quality images and illustrative rendering effects in real-time. The main feature that distinguishes ProteinShader from other free molecular visualization tools is its use of texture mapping techniques that allow two-dimensional images to be mapped onto the curved three-dimensional surfaces of ribbons and tubes with minimum distortion of the images.

  15. Rendering Visible: Painting and Sexuate Subjectivity

    Science.gov (United States)

    Daley, Linda

    2015-01-01

    In this essay, I examine Luce Irigaray's aesthetic of sexual difference, which she develops by extrapolating from Paul Klee's idea that the role of painting is to render the non-visible rather than represent the visible. This idea is the premise of her analyses of phenomenology and psychoanalysis and their respective contributions to understanding…

  16. New light field camera based on physical based rendering tracing

    Science.gov (United States)

    Chung, Ming-Han; Chang, Shan-Ching; Lee, Chih-Kung

    2014-03-01

    Even though light field technology was first invented more than 50 years ago, it did not gain popularity due to the limitation imposed by the computation technology. With the rapid advancement of computer technology over the last decade, the limitation has been uplifted and the light field technology quickly returns to the spotlight of the research stage. In this paper, PBRT (Physical Based Rendering Tracing) was introduced to overcome the limitation of using traditional optical simulation approach to study the light field camera technology. More specifically, traditional optical simulation approach can only present light energy distribution but typically lack the capability to present the pictures in realistic scenes. By using PBRT, which was developed to create virtual scenes, 4D light field information was obtained to conduct initial data analysis and calculation. This PBRT approach was also used to explore the light field data calculation potential in creating realistic photos. Furthermore, we integrated the optical experimental measurement results with PBRT in order to place the real measurement results into the virtually created scenes. In other words, our approach provided us with a way to establish a link of virtual scene with the real measurement results. Several images developed based on the above-mentioned approaches were analyzed and discussed to verify the pros and cons of the newly developed PBRT based light field camera technology. It will be shown that this newly developed light field camera approach can circumvent the loss of spatial resolution associated with adopting a micro-lens array in front of the image sensors. Detailed operational constraint, performance metrics, computation resources needed, etc. associated with this newly developed light field camera technique were presented in detail.

  17. Virtual colonoscopy

    Science.gov (United States)

    Colonoscopy - virtual; CT colonography; Computed tomographic colonography; Colography - virtual ... Differences between virtual and conventional colonoscopy include: VC can view the colon from many different angles. This is not as easy ...

  18. Effects of Viewpoint Jitters Onf Roll Vection

    Directory of Open Access Journals (Sweden)

    Shinji Nakamura

    2011-05-01

    Full Text Available It has been revealed that random viewpoint jitters or periodical viewpoint oscillation superimposed in visual stimulus which simulates the observer's self-motion can enhance visually induced self-motion perception (vection, even if there are sustained conflicts between visual and vestibular information. The effects of jitter/oscillation have been confirmed both using forward self-motion induced by expanding display and horizontal linear self-motion induced laterally moving visual pattern. In the present investigation, we examined whether jitter/oscillation advantage would affect visually induced self-rotation (roll vection induced by rotating visual pattern. In psychophysical experiments with 12 undergraduate participants, we compared perceived strength of roll vection between the stimulus conditions where simulated viewpoint jitters were superimposed or not. The results indicated that viewpoint jitters significantly weakened strength of perceived self-rotation. On the other hand, random roll component superimposed in pure radial expanding pattern can enhance illusory forward self-motion. These results suggest that the effects of viewpoint jitter would affect differently on linear vection induced by expanding optical flow and circular vection induced by visual rotation.

  19. Multi-layer 3D imaging using a few viewpoint images and depth map

    Science.gov (United States)

    Suginohara, Hidetsugu; Sakamoto, Hirotaka; Yamanaka, Satoshi; Suyama, Shiro; Yamamoto, Hirotsugu

    2015-03-01

    In this paper, we propose a new method that makes multi-layer images from a few viewpoint images to display a 3D image by the autostereoscopic display that has multiple display screens in the depth direction. We iterate simple "Shift and Subtraction" processes to make each layer image alternately. The image made in accordance with depth map like a volume slicing by gradations is used as the initial solution of iteration process. Through the experiments using the prototype stacked two LCDs, we confirmed that it was enough to make multi-layer images from three viewpoint images to display a 3D image. Limiting the number of viewpoint images, the viewing area that allows stereoscopic view becomes narrow. To broaden the viewing area, we track the head motion of the viewer and update screen images in real time so that the viewer can maintain correct stereoscopic view within +/- 20 degrees area. In addition, we render pseudo multiple viewpoint images using depth map, then we can generate motion parallax at the same time.

  20. RAY TRACING RENDER MENGGUNAKAN FRAGMENT ANTI ALIASING

    Directory of Open Access Journals (Sweden)

    Febriliyan Samopa

    2008-07-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Rendering is generating surface and three-dimensional effects on an object displayed on a monitor screen. Ray tracing as a rendering method that traces ray for each image pixel has a drawback, that is, aliasing (jaggies effect. There are some methods for executing anti aliasing. One of those methods is OGSS (Ordered Grid Super Sampling. OGSS is able to perform aliasing well. However, this method requires more computation time since sampling of all pixels in the image will be increased. Fragment Anti Aliasing (FAA is a new alternative method that can cope with the drawback. FAA will check the image when performing rendering to a scene. Jaggies effect is only happened at curve and gradient object. Therefore, only this part of object that will experience sampling magnification. After this sampling magnification and the pixel values are computed, then downsample is performed to retrieve the original pixel values. Experimental results show that the software can implement ray tracing well in order to form images, and it can implement FAA and OGSS technique to perform anti aliasing. In general, rendering using FAA is faster than using OGSS

  1. Precise perception of virtual object position in real world

    Institute of Scientific and Technical Information of China (English)

    Lin Liping; Wu Pingdong; Huang Jie; Li Jian

    2009-01-01

    There is a deviation between actual and theoretical perceived positions of virtual object in stereoscopic display. Therefore, methods for precise position perception in real world are proposed in this paper. The causes for the deviation are analyzed on the basis of geometrical optics. Then deviation corrections are performed by error compensation with mathematic method and by remodeling virtual viewpoint dynamically with the movement of physical viewpoint. Experimental results show that these methods can reduce the position deviation to less than 10 millimeter, meeting the requirements for direct manipulation in multi-sensory virtual environment.

  2. Fast computer-generated hologram computation using rendered depth map image

    Science.gov (United States)

    Kazempourradi, Seyedmahdi; Ulusoy, Erdem; Urey, Hakan

    2017-03-01

    We propose a method for computing realistic computer-generated holograms (CGHs) of three-dimensional (3D) objects, where we benefit from well-established graphical processing units (GPUs) and computer graphics techniques to handle occlusion, shading and parallax effects. The graphics render provides a 2D perspective image including occlusion and shading effects. We also extract the depth map data of the scene. The intensity values and 3D positions of object points are extracted by combining the rendered intensity image and the depth map (Z-buffer) image. We divide the depth range into several planes and quantize the depth value of 3D image points to the nearest plane. In the CGH computation part, we perform proper Fresnel transformations of these planar objects and sum them up to create the hologram corresponding to the particular viewpoint. We then repeat the entire procedure for all possible viewpoints and cover the hologram area. The experimental results show that the technique is capable of performing high quality reconstructions in a fast manner.

  3. Automatic Image-Based Pencil Sketch Rendering

    Institute of Scientific and Technical Information of China (English)

    王进; 鲍虎军; 周伟华; 彭群生; 徐迎庆

    2002-01-01

    This paper presents an automatic image-based approach for converting greyscale images to pencil sketches, in which strokes follow the image features. The algorithm first extracts a dense direction field automatically using Logical/Linear operators which embody the drawing mechanism. Next, a reconstruction approach based on a sampling-and-interpolation scheme is introduced to generate stroke paths from the direction field. Finally, pencil strokes are rendered along the specified paths with consideration of image tone and artificial illumination.As an important application, the technique is applied to render portraits from images with little user interaction. The experimental results demonstrate that the approach can automatically achieve compelling pencil sketches from reference images.

  4. Optimization techniques for computationally expensive rendering algorithms

    OpenAIRE

    Navarro Gil, Fernando; Gutiérrez Pérez, Diego; Serón Arbeloa, Francisco José

    2012-01-01

    Realistic rendering in computer graphics simulates the interactions of light and surfaces. While many accurate models for surface reflection and lighting, including solid surfaces and participating media have been described; most of them rely on intensive computation. Common practices such as adding constraints and assumptions can increase performance. However, they may compromise the quality of the resulting images or the variety of phenomena that can be accurately represented. In this thesi...

  5. The Malvinas War from the Argentinian Viewpoint

    Science.gov (United States)

    1988-05-01

    Guerra Aerea. Buenos Aires, October 1982. - Malvinas . Testiaco de Batallas. J. Romero and S. Mate --Ed. Federico Domenech. Valencia, 1984. -The Falklands...DTI( -FI)AC OTIC FORm 70A DOCUMENT PROCESSING SHEET 5.. 5’A1 BE USE MAR 86 I’ M "THE MALVINAS WAR FROM THE ARGENTINIAN VIEWPOINTŔ LT COL RICARDO...UNIVERSITY "THE MALVINAS WAR FROM THE ARGENTINIAN VIEWPOINT" by Ricardo Albert Puche .Lt. Col, SPANISH AIR FORCE A RESEARCH REPORT SUBMITTED TO THE FACULTY

  6. Visualization of Medpor implants using surface rendering

    Institute of Scientific and Technical Information of China (English)

    WANG Meng; GUI Lai; LIU Xiao-jing

    2011-01-01

    Background The Medpor surgical implant is one of the easiest implants in clinical practice, especially in craniomaxillofacial surgery. It is often used as a bone substitute material for the repair of skull defects and facial deformities. The Medpor implant has several advantages but its use is limited because it is radiolucent in both direct radiography and conventional computed tomography, causing serious problems with visualization.Methods In this study, a new technique for visualizing Medpor implants was evaluated in 10 patients who had undergone facial reconstruction using the material. Continuous volume scans were made using a 16-channel tomographic scanner and 3D reconstruction software was used to create surface renderings. The threshold values for surface renderings of the implant ranged from -70 HU to -20 HU, with bone as the default.Results The shape of the implants and the spatial relationship between bone and implant could both be displayed.Conclusion Surface rendering can allow successful visualization of Medpor implants in the body.

  7. Image-based haptic roughness estimation and rendering for haptic palpation from in vivo skin image.

    Science.gov (United States)

    Kim, Kwangtaek

    2017-08-08

    Despite the advancement of measuring technologies, there was a need for palpation by hands to be able to better diagnose skin diseases and to learn about the tactile properties of in vivo skin surface. However, directly touching in vivo skin surface can cause secondary infections or damages. Therefore, a technology providing infection- and damage-free skin palpations and precise haptic skin roughness rendering is needed. A multidimensional (2D and 3D) rendering system was developed for multimodal (visual and haptic) rendering that can run with any given in vivo input skin images. For haptic rendering, a commercial haptic device with 3 degrees of freedom (3DOF), Geomagic Touch X, was used. To improve haptic roughness rendering, a force shading algorithm that reduces force discontinuity on rough surface patches but preserves the original roughness values was implemented and applied. In addition, a new image-based roughness estimation method was introduced and the results were compared with haptic roughness results to verify roughness rendering in the system. The developed haptic roughness rendering system will help to diagnose abnormalities on in vivo skin surfaces by virtual haptic palpation with no concern about secondary infections or damages (caused by touch interactions) especially in case of psoriasis, atopic dermatitis, or aging, which results in significant changes of skin roughness. Besides, the system can also be a good tool to examine skin condition changes before and after the use of skin care products (cosmetics). In addition, the proposed 2D skin roughness estimation method can be applied for mobile applications to provide an online roughness estimation tool with a simple phone camera.

  8. Virtual Worlds

    OpenAIRE

    Novák, František

    2009-01-01

    The bachelor's thesis is focused on highlighting the development of virtual worlds. The paper summarizes the evolution of virtual reality. Current virtual worlds are compared in fundamental aspects, such as sociology, economics and education. Social sphere describes the interaction in virtual reality and its specialities. Economical sphere is focused on comparison of real and virtual economies, including their economic indicators. Educational sphere describes the sciences, which are best usea...

  9. Visible Quotation : The multimodal expression of viewpoint

    NARCIS (Netherlands)

    Stec, Kashmiri Kristina Mukti

    2016-01-01

    The central theme of this dissertation is multimodal viewpoint – that is, the way that bodily actions work together with spoken language to express the perspective of characters within a narrative. Drawing on research in cognitive linguistics, conversation analysis, gesture studies, and signed langu

  10. Newborns' Face Recognition over Changes in Viewpoint

    Science.gov (United States)

    Turati, Chiara; Bulf, Hermann; Simion, Francesca

    2008-01-01

    The study investigated the origins of the ability to recognize faces despite rotations in depth. Four experiments are reported that tested, using the habituation technique, whether 1-to-3-day-old infants are able to recognize the invariant aspects of a face over changes in viewpoint. Newborns failed to recognize facial perceptual invariances…

  11. GPU Pro 4 advanced rendering techniques

    CERN Document Server

    Engel, Wolfgang

    2013-01-01

    GPU Pro4: Advanced Rendering Techniques presents ready-to-use ideas and procedures that can help solve many of your day-to-day graphics programming challenges. Focusing on interactive media and games, the book covers up-to-date methods producing real-time graphics. Section editors Wolfgang Engel, Christopher Oat, Carsten Dachsbacher, Michal Valient, Wessam Bahnassi, and Sebastien St-Laurent have once again assembled a high-quality collection of cutting-edge techniques for advanced graphics processing unit (GPU) programming. Divided into six sections, the book begins with discussions on the abi

  12. GPU PRO 3 Advanced rendering techniques

    CERN Document Server

    Engel, Wolfgang

    2012-01-01

    GPU Pro3, the third volume in the GPU Pro book series, offers practical tips and techniques for creating real-time graphics that are useful to beginners and seasoned game and graphics programmers alike. Section editors Wolfgang Engel, Christopher Oat, Carsten Dachsbacher, Wessam Bahnassi, and Sebastien St-Laurent have once again brought together a high-quality collection of cutting-edge techniques for advanced GPU programming. With contributions by more than 50 experts, GPU Pro3: Advanced Rendering Techniques covers battle-tested tips and tricks for creating interesting geometry, realistic sha

  13. Defects of organization in rendering medical aid

    Directory of Open Access Journals (Sweden)

    Shavkat Islamov

    2010-09-01

    Full Text Available The defects of organization at the medical institution mean disturbance of rules, norms and order of rendering of medical aid. The number of organization defects in Uzbekistan increased from 20.42%, in 1999 to 25.46% in 2001 with gradual decrease to 19.9% in 2003 and 16.66%, in 2006 and gradual increase to 21.95% and 28.28% (P<0.05 in 2005 and 2008. Among the groups of essential defects of organization there were following: disturbance of transportation rules, lack of dispensary care, shortcomings in keeping medical documentation.

  14. Realistic Visualization of Virtual Views

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    Computer Graphics allows us today to visualize in real-time innumerable and amazing scenarios with no limits on viewpoint and viewing direction. However, to design accurate object models and to simulate all the physical phenomena occurring in analogous real situations often represents a job...... that can be impractical and sometime impossible. In addition, the artificial nature of data often makes visualized virtual scenarios not realistic enough. Not realistic in the sense that a synthetic scene is easy to discriminate visually from a natural scene. A new field of research has consequently...... developed and received much attention in recent years: Realistic Virtual View Synthesis. The main goal is a high fidelity representation of virtual scenarios while easing modeling and physical phenomena simulation. In particular, realism is achieved by the transfer to the novel view of all the physical...

  15. Real-Time Massive Model Rendering

    CERN Document Server

    Yoon, Sung-eui; Kasik, David

    2008-01-01

    Interactive display and visualization of large geometric and textured models is becoming a fundamental capability. There are numerous application areas, including games, movies, CAD, virtual prototyping, and scientific visualization. One of observations about geometric models used in interactive applications is that their model complexity continues to increase because of fundamental advances in 3D modeling, simulation, and data capture technologies. As computing power increases, users take advantage of the algorithmic advances and generate even more complex models and data sets. Therefore, the

  16. Overview of Free-viewpoint TV (FTV)

    Science.gov (United States)

    Tanimoto, Masayuki

    We have developed a new type of television named Free-viewpoint TV (FTV). FTV is an innovative visual medium that enables us to view a 3D scene by freely changing our viewpoints. FTV is based on the ray-space method that represents one ray in real space with one point in the ray space. We have also developed new type of ray capture and display technologies such as a 360∘ mirror-scan ray capturing system and a 360∘ ray-reproducing display. The international standardization of FTV has been made in MPEG. The first phase of FTV is Multiview Video Coding (MVC), and the second phase is 3D Video (3DV).

  17. Simulation and training of lumbar punctures using haptic volume rendering and a 6DOF haptic device

    Science.gov (United States)

    Färber, Matthias; Heller, Julika; Handels, Heinz

    2007-03-01

    The lumbar puncture is performed by inserting a needle into the spinal chord of the patient to inject medicaments or to extract liquor. The training of this procedure is usually done on the patient guided by experienced supervisors. A virtual reality lumbar puncture simulator has been developed in order to minimize the training costs and the patient's risk. We use a haptic device with six degrees of freedom (6DOF) to feedback forces that resist needle insertion and rotation. An improved haptic volume rendering approach is used to calculate the forces. This approach makes use of label data of relevant structures like skin, bone, muscles or fat and original CT data that contributes information about image structures that can not be segmented. A real-time 3D visualization with optional stereo view shows the punctured region. 2D visualizations of orthogonal slices enable a detailed impression of the anatomical context. The input data consisting of CT and label data and surface models of relevant structures is defined in an XML file together with haptic rendering and visualization parameters. In a first evaluation the visible human male data has been used to generate a virtual training body. Several users with different medical experience tested the lumbar puncture trainer. The simulator gives a good haptic and visual impression of the needle insertion and the haptic volume rendering technique enables the feeling of unsegmented structures. Especially, the restriction of transversal needle movement together with rotation constraints enabled by the 6DOF device facilitate a realistic puncture simulation.

  18. Nonintrusive viewpoint tracking for 3D for perception in smart video conference

    Science.gov (United States)

    Desurmont, Xavier; Martinez-Ponte, Isabel; Meessen, Jerome; Delaigle, Jean-François

    2006-02-01

    Globalisation of people's interaction in the industrial world and ecological cost of transport make video-conference an interesting solution for collaborative work. However, the lack of immersive perception makes video-conference not appealing. TIFANIS tele-immersion system was conceived to let users interact as if they were physically together. In this paper, we focus on an important feature of the immersive system: the automatic tracking of the user's point of view in order to render correctly in his display the scene from the ther site. Viewpoint information has to be computed in a very short time and the detection system should be no intrusive, otherwise it would become cumbersome for the user, i.e. he would lose the feeling of "being there". The viewpoint detection system consists of several modules. First, an analysis module identifies and follows regions of interest (ROI) where faces are detected. We will show the cooperative approach between spatial detection and temporal tracking. Secondly, an eye detector finds the position of the eyes within faces. Then, the 3D positions of the eyes are deduced using stereoscopic images from a binocular camera. Finally, the 3D scene is rendered in real-time according to the new point of view.

  19. Viewpoint-independent contextual cueing effect

    Directory of Open Access Journals (Sweden)

    taiga etsuchiai

    2012-06-01

    Full Text Available We usually perceive things in our surroundings as unchanged despite viewpoint changes caused by self-motion. The visual system therefore must have a function to process objects independently of viewpoint. In this study, we examined whether viewpoint-independent spatial layout can be obtained implicitly. For this purpose, we used a contextual cueing effect, a learning effect of spatial layout in visual search displays known to be an implicit effect. We compared the transfer of the contextual cueing effect between cases with and without self-motion by using visual search displays for 3D objects, which changed according to the participant’s assumed location for viewing the stimuli. The contextual cueing effect was obtained with self-motion but disappeared when the display changed without self-motion. This indicates that there is an implicit learning effect in spatial coordinates and suggests that the spatial representation of object layouts or scenes can be obtained and updated implicitly. We also showed that binocular disparity play an important role in the layout representations.

  20. Free viewpoint video generation based on coding information of H.264/AVC

    Science.gov (United States)

    Lin, Chi-Kun; Hung, Yu-Chen; Tang, Chia-Tong; Hwang, Jenq-Neng; Yang, Jar-Ferr

    2010-07-01

    Free viewpoint television (FTV) is a new technology that allows viewers to change view angles freely while watching TV programs. FTV requires a strong support of multi-view video codec (MVC), such as H.264/MVC defined by Joint Video Team(JVT). In this paper, we propose an FTV system which can produce videos as perceived in any view angles based on limited number of viewpoint videos decoded from H.264/MVC bitstreams. In this system, the decoded disparity vectors and motion vectors are diffused to produce smooth disparity fields for virtual view reconstruction. Decoded residue data under motion compensation are used as a match criterion. The proposed system not only greatly reduces the computation burden in creating FTV, but also improve the synthesized viewing quality due to the use of quarter pixel precision of H.264.

  1. Application of Virtual and Augmented reality to geoscientific teaching and research.

    Science.gov (United States)

    Hodgetts, David

    2017-04-01

    The geological sciences are the ideal candidate for the application of Virtual Reality (VR) and Augmented Reality (AR). Digital data collection techniques such as laser scanning, digital photogrammetry and the increasing use of Unmanned Aerial Vehicles (UAV) or Small Unmanned Aircraft (SUA) technology allow us to collect large datasets efficiently and evermore affordably. This linked with the recent resurgence in VR and AR technologies make these 3D digital datasets even more valuable. These advances in VR and AR have been further supported by rapid improvements in graphics card technologies, and by development of high performance software applications to support them. Visualising data in VR is more complex than normal 3D rendering, consideration needs to be given to latency, frame-rate and the comfort of the viewer to enable reasonably long immersion time. Each frame has to be rendered from 2 viewpoints (one for each eye) requiring twice the rendering than for normal monoscopic views. Any unnatural effects (e.g. incorrect lighting) can lead to an uncomfortable VR experience so these have to be minimised. With large digital outcrop datasets comprising 10's-100's of millions of triangles this is challenging but achievable. Apart from the obvious "wow factor" of VR there are some serious applications. It is often the case that users of digital outcrop data do not appreciate the size of features they are dealing with. This is not the case when using correctly scaled VR, and a true sense of scale can be achieved. In addition VR provides an excellent way of performing quality control on 3D models and interpretations and errors are much more easily visible. VR models can then be used to create content that can then be used in AR applications closing the loop and taking interpretations back into the field.

  2. Photon Differential Splatting for Rendering Caustics

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall; Schjøth, Lars; Erleben, Kenny;

    2014-01-01

    We present a photon splatting technique which reduces noise and blur in the rendering of caustics. Blurring of illumination edges is an inherent problem in photon splatting, as each photon is unaware of its neighbours when being splatted. This means that the splat size is usually based...... on heuristics rather than knowledge of the local flux density. We use photon differentials to determine the size and shape of the splats such that we achieve adaptive anisotropic flux density estimation in photon splatting. As compared to previous work that uses photon differentials, we present the first method...... where no photons or beams or differentials need to be stored in a map. We also present improvements in the theory of photon differentials, which give more accurate results and a faster implementation. Our technique has good potential for GPU acceleration, and we limit the number of parameters requiring...

  3. Constructing And Rendering Vectorised Photographic Images

    Directory of Open Access Journals (Sweden)

    P. J. Willis

    2013-06-01

    Full Text Available We address the problem of representing captured images in the continuous mathematical space more usually associated with certain forms of drawn ('vector' images. Such an image is resolution-independent so can be used as a master for varying resolution-specific formats. We briefly describe the main features of a vectorising codec for photographic images, whose significance is that drawing programs can access images and image components as first-class vector objects. This paper focuses on the problem of rendering from the isochromic contour form of a vectorised image and demonstrates a new fill algorithm which could also be used in drawing generally. The fill method is described in terms of level set diffusion equations for clarity. Finally we show that image warping is both simplified and enhanced in the vector form and that we can demonstrate real histogram equalisation with genuinely rectangular histograms straightforwardly.

  4. Virtual box

    DEFF Research Database (Denmark)

    Stougaard, Malthe Kirkhoff

    2007-01-01

    . This paper reports on the design, implementation and initial evaluation of Virtual Box. Virtual Box attempts to create a physical and engaging context in order to support reciprocal interactions with expressive content. An implemented version of Virtual Box is evaluated in a location-aware environment...

  5. Synthesizing wide-angle and arbitrary view-point images from a circular camera array

    Science.gov (United States)

    Fukushima, Norishige; Yendo, Tomohiro; Fujii, Toshiaki; Tanimoto, Masayuki

    2006-02-01

    We propose a technique of Imaged-Based Rendering(IBR) using a circular camera array. By the result of having recorded the scene as surrounding the surroundings, we can synthesize a more dynamic arbitrary viewpoint images and a wide angle images like a panorama . This method is based on Ray- Space, one of the image-based rendering, like Light Field. Ray-Space is described by the position (x, y) and a direction (θ, φ) of the ray's parameter which passes a reference plane. All over this space, when the camera has been arranged circularly, the orbit of the point equivalent to an Epipor Plane Image(EPI) at the time of straight line arrangement draws a sin curve. Although described in a very clear form, in case a rendering is performed, pixel of which position of which camera being used and the work for which it asks become complicated. Therefore, the position (u, v) of the position (s, t) pixel of a camera like Light Filed redescribes space expression. It makes the position of a camera a polar-coordinates system (r, theta), and is making it close to description of Ray-Space. Thereby, although the orbit of a point serves as a complicated periodic function of periodic 2pi, the handling of a rendering becomes easy. From such space, the same as straight line arrangement, arbitrary viewpoint picture synthesizing is performed only due to a geometric relationship between cameras. Moreover, taking advantage of the characteristic of concentrating on one circular point, we propose the technique of generating a wide-angle picture like a panorama. When synthesizing a viewpoint, since it is overlapped and is recording the ray of all the directions of the same position, this becomes possible. Having stated until now is the case where it is a time of the camera fully having been arranged and a plenoptic sampling being filled. The discrete thing which does not fill a sampling is described from here. When arranging a camera in a straight line and compounding a picture, in spite of

  6. See-through techniques for referential awareness in collaborative virtual reality

    OpenAIRE

    Argelaguet Sanz, Fernando; Kulik, Alexander; Kunert, André; Andújar Gran, Carlos Antonio; Froehlich, Bernd

    2011-01-01

    Multi-user virtual reality systems enable natural collaboration in share virtual worlds. Users can talk to each other, gesture and point into the virtual scenery as if it were real. As in reality, refer ring to objects by pointing results often in a situation whereon objects are occluded from the other users’ viewpoints. While in reality this problem can only be solved by adapting the viewing position, specialized individual views of the shared virtual scene enable various other so...

  7. Resolution-independent surface rendering using programmable graphics hardware

    Science.gov (United States)

    Loop, Charles T.; Blinn, James Frederick

    2008-12-16

    Surfaces defined by a Bezier tetrahedron, and in particular quadric surfaces, are rendered on programmable graphics hardware. Pixels are rendered through triangular sides of the tetrahedra and locations on the shapes, as well as surface normals for lighting evaluations, are computed using pixel shader computations. Additionally, vertex shaders are used to aid interpolation over a small number of values as input to the pixel shaders. Through this, rendering of the surfaces is performed independently of viewing resolution, allowing for advanced level-of-detail management. By individually rendering tetrahedrally-defined surfaces which together form complex shapes, the complex shapes can be rendered in their entirety.

  8. Wireless virtualization

    CERN Document Server

    Wen, Heming; Le-Ngoc, Tho

    2013-01-01

    This SpringerBriefs is an overview of the emerging field of wireless access and mobile network virtualization. It provides a clear and relevant picture of the current virtualization trends in wireless technologies by summarizing and comparing different architectures, techniques and technologies applicable to a future virtualized wireless network infrastructure. The readers are exposed to a short walkthrough of the future Internet initiative and network virtualization technologies in order to understand the potential role of wireless virtualization in the broader context of next-generation ubiq

  9. The Potential for Scientific Collaboration in Virtual Ecosystems

    Science.gov (United States)

    Magerko, Brian

    2010-01-01

    This article explores the potential benefits of creating "virtual ecosystems" from real-world data. These ecosystems are intended to be realistic virtual representations of environments that may be costly or difficult to access in person. They can be constructed as 3D worlds rendered from stereo video data, augmented with scientific data, and then…

  10. The Potential for Scientific Collaboration in Virtual Ecosystems

    Science.gov (United States)

    Magerko, Brian

    2010-01-01

    This article explores the potential benefits of creating "virtual ecosystems" from real-world data. These ecosystems are intended to be realistic virtual representations of environments that may be costly or difficult to access in person. They can be constructed as 3D worlds rendered from stereo video data, augmented with scientific data, and then…

  11. Efficient and Effective Volume Visualization with Enhanced Isosurface Rendering

    CERN Document Server

    Yang, Fei; Tian, Jie

    2012-01-01

    Compared with full volume rendering, isosurface rendering has several well recognized advantages in efficiency and accuracy. However, standard isosurface rendering has some limitations in effectiveness. First, it uses a monotone colored approach and can only visualize the geometry features of an isosurface. The lack of the capability to illustrate the material property and the internal structures behind an isosurface has been a big limitation of this method in applications. Another limitation of isosurface rendering is the difficulty to reveal physically meaningful structures, which are hidden in one or multiple isosurfaces. As such, the application requirements of extract and recombine structures of interest can not be implemented effectively with isosurface rendering. In this work, we develop an enhanced isosurface rendering technique to improve the effectiveness while maintaining the performance efficiency of the standard isosurface rendering. First, an isosurface color enhancement method is proposed to il...

  12. HAPTIC RENDERING OF THIN AND SOFT OBJECTS

    Directory of Open Access Journals (Sweden)

    Anish Garg

    2013-02-01

    Full Text Available In this work, we take up the problem of modeling deformations, both local and global, along with stable translations for radially-thin virtual objects especially like that of a wire or a spaghetti noodle, during haptic manipulation. To achieve this we recommend the use of mass-spring systems rather than geometric models like vertex based and free form deformation as they do not model the physics behind the interactions. Finite Equation Methods (FEMs are also not chosen as they are computationally expensive for fast haptic interactions and force feedback. We have explored different types of distribution of masses within the volume of the object, in order to come up with a suitable distribution of masses and network of springs and dampers so that the simulations mimic the behavior of a real object. We also model the constraint forces like normal and frictional forces between the object and the plane on which it is kept. Further, we simulate the effect of a varying temperature distribution of the object and discuss how anisotropic deformation of an object may be effected. We demonstrate through experimentations that it is indeed possible to haptically interact with virtual soft objects.

  13. Direct volume rendering methods for cell structures.

    Science.gov (United States)

    Martišek, Dalibor; Martišek, Karel

    2012-01-01

    The study of the complicated architecture of cell space structures is an important problem in biology and medical research. Optical cuts of cells produced by confocal microscopes enable two-dimensional (2D) and three-dimensional (3D) reconstructions of observed cells. This paper discuses new possibilities for direct volume rendering of these data. We often encounter 16 or more bit images in confocal microscopy of cells. Most of the information contained in these images is unsubstantial for the human vision. Therefore, it is necessary to use mathematical algorithms for visualization of such images. Present software tools as OpenGL or DirectX run quickly in graphic station with special graphic cards, run very unsatisfactory on PC without these cards and outputs are usually poor for real data. These tools are black boxes for a common user and make it impossible to correct and improve them. With the method proposed, more parameters of the environment can be set, making it possible to apply 3D filters to set the output image sharpness in relation to the noise. The quality of the output is incomparable to the earlier described methods and is worth increasing the computing time. We would like to offer mathematical methods of 3D scalar data visualization describing new algorithms that run on standard PCs very well.

  14. Integration of the Shuttle RMS/CBM Positioning Virtual Environment Simulation

    Science.gov (United States)

    Dumas, Joseph D.

    1996-01-01

    more safely and conveniently with little additional cost. In order to render and view the RMS and CBMs in a virtual world, the position and orientation of the end effector in three-dimensional space must be known with a high degree of accuracy. A precision video alignment sensor has been developed which can determine the position and orientation of the controlled element relative to the target CBM within approximately one-sixteenth inch and 0.07 angular degrees. Such a sensor could replace or augment the boresighted camera mentioned above. The computer system used to render the virtual world and the position tracking systems which might be used to monitor the user's movements (in order to adjust the viewpoint in virtual space) are small enough to carry to orbit. Thus, such a system would be feasible for use in constructing structures in space.

  15. High-power graphic computers for visual simulation: a real-time--rendering revolution

    Science.gov (United States)

    Kaiser, M. K.

    1996-01-01

    Advances in high-end graphics computers in the past decade have made it possible to render visual scenes of incredible complexity and realism in real time. These new capabilities make it possible to manipulate and investigate the interactions of observers with their visual world in ways once only dreamed of. This paper reviews how these developments have affected two preexisting domains of behavioral research (flight simulation and motion perception) and have created a new domain (virtual environment research) which provides tools and challenges for the perceptual psychologist. Finally, the current limitations of these technologies are considered, with an eye toward how perceptual psychologist might shape future developments.

  16. Virtual colonoscopy.

    Science.gov (United States)

    Vining, D J

    1997-04-01

    A new method for colon examination, virtual colonoscopy, has been created by combining spiral computed tomography and virtual reality computer technology. If virtual colonoscopy proves equal to or superior to traditional colonoscopy in sensitivity and specificity for cancer screening, it would yield significant clinical and public health benefits because of its potential for increased acceptance among patients as well as its considerably lower cost and risks.

  17. Virtual volatility

    Science.gov (United States)

    Silva, A. Christian; Prange, Richard E.

    2007-03-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation strategy.

  18. Virtual volatility

    OpenAIRE

    A. Christian Silva; Prange, Richard E.

    2006-01-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation st...

  19. Virtual Reflexes

    OpenAIRE

    2014-01-01

    Virtual Reality is used successfully to treat people for regular phobias. A new challenge is to develop Virtual Reality Exposure Training for social skills. Virtual actors in such systems have to show appropriate social behavior including emotions, gaze, and keeping distance. The behavior must be realistic and real-time. Current approaches consist of four steps: 1) trainee social signal detection, 2) cognitive-affective interpretation, 3) determination of the appropriate bodily responses, and...

  20. Virtual reality

    OpenAIRE

    Zheng, JM; Chan, KW; Gibson, I.

    1998-01-01

    Virtual reality is still in its infancy. However, many contemporary applications already have proven virtual reality to be indispensable to everyday life. For instance, the technology of virtual product design and manufacturing makes the new products better and cheaper. The applications of VR in medicine allow doctors to diagnose a disease more accurately. Without a doubt, it has and will foster more innovative research and applications. High-resolution, low-lag and low-price systems will be ...

  1. Virtual projects

    DEFF Research Database (Denmark)

    Svejvig, Per; Commisso, Trine Hald

    2012-01-01

    that the best practice knowledge has not permeated sufficiently to the practice. Furthermore, the appropriate application of information and communication technology (ICT) remains a big challenge, and finally project managers are not sufficiently trained in organizing and conducting virtual projects......Virtual projects are common with global competition, market development, and not least the financial crisis forcing organizations to reduce their costs drastically. Organizations therefore have to place high importance on ways to carry out virtual projects and consider appropriate practices...

  2. Overview of FTV (free-viewpoint television)

    Science.gov (United States)

    Tanimoto, Masayuki

    2010-07-01

    We have developed a new type of television named FTV (Free-viewpoint TV). FTV is the ultimate 3DTV that enables us to view a 3D scene by freely changing our viewpoints. We proposed the concept of FTV and constructed the world's first real-time system including the complete chain of operation from image capture to display. FTV is based on the rayspace method that represents one ray in real space with one point in the ray-space. We have developed ray capture, processing and display technologies for FTV. FTV can be carried out today in real time on a single PC or on a mobile player. We also realized FTV with free listening-point audio. The international standardization of FTV has been conducted in MPEG. The first phase of FTV was MVC (Multi-view Video Coding) and the second phase is 3DV (3D Video). MVC was completed in May 2009. The Blu-ray 3D specification has adopted MVC for compression. 3DV is a standard that targets serving a variety of 3D displays. The view generation function of FTV is used to decouple capture and display in 3DV. FDU (FTV Data Unit) is proposed as a data format for 3DV. FTU can compensate errors of the synthesized views caused by depth error.

  3. The ViewPoint radioprotection supervision workstation; Poste de supervision radioprotection viewpoint

    Energy Technology Data Exchange (ETDEWEB)

    Gaultier, E. [APVL Ingenierie- 6, bd Nobel - Equatop La Rabelais - 37540 Saint Cyr sur Loire (France)

    2009-07-01

    The author briefly presents the ViewPoint supervision global solution which incorporates audio and video advanced technologies to manage radioprotection operational measurements. Data can be transmitted by-wire or wireless. It can integrate a large number of radioprotection measurement instruments, such as a belt for the monitoring of physiological parameters (body temperature, breathing rhythm, body posture)

  4. HDlive rendering images of the fetal stomach: a preliminary report.

    Science.gov (United States)

    Inubashiri, Eisuke; Abe, Kiyotaka; Watanabe, Yukio; Akutagawa, Noriyuki; Kuroki, Katumaru; Sugawara, Masaki; Maeda, Nobuhiko; Minami, Kunihiro; Nomura, Yasuhiro

    2015-01-01

    This study aimed to show reconstruction of the fetal stomach using the HDlive rendering mode in ultrasound. Seventeen healthy singleton fetuses at 18-34 weeks' gestational age were observed using the HDlive rendering mode of ultrasound in utero. In all of the fetuses, we identified specific spatial structures, including macroscopic anatomical features (e.g., the pyrous, cardia, fundus, and great curvature) of the fetal stomach, using the HDlive rendering mode. In particular, HDlive rendering images showed remarkably fine details that appeared as if they were being viewed under an endoscope, with visible rugal folds after 27 weeks' gestational age. Our study suggests that the HDlive rendering mode can be used as an additional method for evaluating the fetal stomach. The HDlive rendering mode shows detailed 3D structural images and anatomically realistic images of the fetal stomach. This technique may be effective in prenatal diagnosis for examining detailed information of fetal organs.

  5. 3D-TV System with Depth-Image-Based Rendering Architectures, Techniques and Challenges

    CERN Document Server

    Zhao, Yin; Yu, Lu; Tanimoto, Masayuki

    2013-01-01

    Riding on the success of 3D cinema blockbusters and advances in stereoscopic display technology, 3D video applications have gathered momentum in recent years. 3D-TV System with Depth-Image-Based Rendering: Architectures, Techniques and Challenges surveys depth-image-based 3D-TV systems, which are expected to be put into applications in the near future. Depth-image-based rendering (DIBR) significantly enhances the 3D visual experience compared to stereoscopic systems currently in use. DIBR techniques make it possible to generate additional viewpoints using 3D warping techniques to adjust the perceived depth of stereoscopic videos and provide for auto-stereoscopic displays that do not require glasses for viewing the 3D image.   The material includes a technical review and literature survey of components and complete systems, solutions for technical issues, and implementation of prototypes. The book is organized into four sections: System Overview, Content Generation, Data Compression and Transmission, and 3D V...

  6. Toward the light field display: autostereoscopic rendering via a cluster of projectors.

    Science.gov (United States)

    Yang, Ruigang; Huang, Xinyu; Li, Sifang; Jaynes, Christopher

    2008-01-01

    Ultimately, a display device should be capable of reproducing the visual effects observed in reality. In this paper we introduce an autostereoscopic display that uses a scalable array of digital light projectors and a projection screen augmented with microlenses to simulate a light field for a given three-dimensional scene. Physical objects emit or reflect light in all directions to create a light field that can be approximated by the light field display. The display can simultaneously provide many viewers from different viewpoints a stereoscopic effect without head tracking or special viewing glasses. This work focuses on two important technical problems related to the light field display; calibration and rendering. We present a solution to automatically calibrate the light field display using a camera and introduce two efficient algorithms to render the special multi-view images by exploiting their spatial coherence. The effectiveness of our approach is demonstrated with a four-projector prototype that can display dynamic imagery with full parallax.

  7. Virtual Laboratories and Virtual Worlds

    CERN Document Server

    Hut, Piet

    2007-01-01

    Since we cannot put stars in a laboratory, astrophysicists had to wait till the invention of computers before becoming laboratory scientists. For half a century now, we have been conducting experiments in our virtual laboratories. However, we ourselves have remained behind the keyboard, with the screen of the monitor separating us from the world we are simulating. Recently, 3D on-line technology, developed first for games but now deployed in virtual worlds like Second Life, is beginning to make it possible for astrophysicists to enter their virtual labs themselves, in virtual form as avatars. This has several advantages, from new possibilities to explore the results of the simulations to a shared presence in a virtual lab with remote collaborators on different continents. I will report my experiences with the use of Qwaq Forums, a virtual world developed by a new company (see http://www.qwaq.com)

  8. Fast combinative volume rendering by indexed data structure

    Institute of Scientific and Technical Information of China (English)

    孙文武; 王文成; 吴恩华

    2001-01-01

    It is beneficial to study the interesting contents in a data set by combining and rendering variouscontents of the data. In this regard, an indexed data structure is proposed to facilitate the reorganization of data so that the contents of the data can be combined conveniently and only the selected contents in the data are processed for rendering. Based on the structure, the cells of different contents can be queued up easily so that the volume rendering can be conducted more accurately and quickly. Experimental results show that the indexed data structure is very efficient in improving combinative volume rendering.

  9. Adapting virtual camera behaviour through player modelling

    DEFF Research Database (Denmark)

    Burelli, Paolo; Yannakakis, Georgios N.

    2015-01-01

    Research in virtual camera control has focused primarily on finding methods to allow designers to place cameras effectively and efficiently in dynamic and unpredictable environments, and to generate complex and dynamic plans for cinematography in virtual environments. In this article, we propose...... a novel approach to virtual camera control, which builds upon camera control and player modelling to provide the user with an adaptive point-of-view. To achieve this goal, we propose a methodology to model the player’s preferences on virtual camera movements and we employ the resulting models to tailor...... the viewpoint movements to the player type and her game-play style. Ultimately, the methodology is applied to a 3D platform game and is evaluated through a controlled experiment; the results suggest that the resulting adaptive cinematographic experience is favoured by some player types and it can generate...

  10. Architecture of web services in the enhancement of real-time 3D video virtualization in cloud environment

    Science.gov (United States)

    Bada, Adedayo; Wang, Qi; Alcaraz-Calero, Jose M.; Grecos, Christos

    2016-04-01

    This paper proposes a new approach to improving the application of 3D video rendering and streaming by jointly exploring and optimizing both cloud-based virtualization and web-based delivery. The proposed web service architecture firstly establishes a software virtualization layer based on QEMU (Quick Emulator), an open-source virtualization software that has been able to virtualize system components except for 3D rendering, which is still in its infancy. The architecture then explores the cloud environment to boost the speed of the rendering at the QEMU software virtualization layer. The capabilities and inherent limitations of Virgil 3D, which is one of the most advanced 3D virtual Graphics Processing Unit (GPU) available, are analyzed through benchmarking experiments and integrated into the architecture to further speed up the rendering. Experimental results are reported and analyzed to demonstrate the benefits of the proposed approach.

  11. Virtual Acoustics

    Science.gov (United States)

    Lokki, Tapio; Savioja, Lauri

    The term virtual acoustics is often applied when sound signal is processed to contain features of a simulated acoustical space and sound is spatially reproduced either with binaural or with multichannel techniques. Therefore, virtual acoustics consists of spatial sound reproduction and room acoustics modeling.

  12. Viewpoint Diversity and Media Consolidation: An Empirical Study

    National Research Council Canada - National Science Library

    Daniel E. Ho; Kevin M. Quinn

    2009-01-01

    .... Appellate courts and, in turn, the Federal Communications Commission have increasingly demanded evidence for this convergence hypothesis, but extant empirical measures of viewpoint diversity sidestep...

  13. Virtual materiality

    DEFF Research Database (Denmark)

    Søndergaard, Dorte Marie

    an interesting platform for further development including virtual materiality and agency. If we choose to proceed along this line – some of our steps would include attention to the following points: 1. Working with virtual realities first of all undermines a pure realist conceptualization of materiality. We need......There are two questions that feed the curiosity of this paper: a theoretical question connected to the conceptualization of materiality across the real/virtual divide and an empirical question connected to the understanding of virtual experiences in children’s lives when studied in relation...... as their recounts of them and 3. the consumption of other media products like movies, reality shows, YouTube videos etc. How do we theorize ‘matter’ in such dimensions? Is it possible to theorize virtual matter as ‘materiality’ in line with any real life materiality? What conceptualization will help us understand...

  14. Virtual projects

    DEFF Research Database (Denmark)

    Svejvig, Per; Commisso, Trine Hald

    2012-01-01

    Virtual projects are common with global competition, market development, and not least the financial crisis forcing organizations to reduce their costs drastically. Organizations therefore have to place high importance on ways to carry out virtual projects and consider appropriate practices...... for performing these projects. This paper compares best practices with practiced practices for virtual projects and discusses ways to bridge the gap between them. We have studied eleven virtual projects in five Danish organizations and compared them with a predefined list of best practices compiled from...... that the best practice knowledge has not permeated sufficiently to the practice. Furthermore, the appropriate application of information and communication technology (ICT) remains a big challenge, and finally project managers are not sufficiently trained in organizing and conducting virtual projects...

  15. Virtual Exploratories

    DEFF Research Database (Denmark)

    Jensen, Sisse Siggaard

    2006-01-01

    This paper proposes the notion of activity-systems to denote a virtual frame of activity that requires mutually coordinated action. The underlying assumption is that such framings may support the informal learning and reflective practices of actors, and especially so, when they are provoking...... and challenging. It is suggested that the prevailing ‘traditions’ of collaborative learning and knowledge sharing need to be challenged and complemented, if we are to be able to support the variety and the diversity in the repertoires of virtual learning activities. In order to conceptualize such activity......-systems, the paper introduces the designing strategy referred to as virtual exploratories. Some of the advanced virtual worlds may inspire the design of such provoking and challenging virtual exploratories, and especially the Massively Multi-User Online Role-Playing Games (MMORPGS). However, if we have to learn from...

  16. CUR from a Sparse Optimization Viewpoint

    CERN Document Server

    Bien, Jacob; Mahoney, Michael W

    2010-01-01

    The CUR decomposition provides an approximation of a matrix $X$ that has low reconstruction error and that is sparse in the sense that the resulting approximation lies in the span of only a few columns of $X$. In this regard, it appears to be similar to many sparse PCA methods. However, CUR takes a randomized algorithmic approach, whereas most sparse PCA methods are framed as convex optimization problems. In this paper, we try to understand CUR from a sparse optimization viewpoint. We show that CUR is implicitly optimizing a sparse regression objective and, furthermore, cannot be directly cast as a sparse PCA method. We also observe that the sparsity attained by CUR possesses an interesting structure, which leads us to formulate a sparse PCA method that achieves a CUR-like sparsity.

  17. Transplant organizational structures: viewpoints from established centers.

    Science.gov (United States)

    Abouljoud, M; Klintmalm, G; Whitehouse, S

    2012-10-01

    This personal viewpoint report summarizes the responses of a survey targeting established transplant programs with a structured framework, such as center, institute, or department, and stability of leadership to assure valuable experiential observations. The 18-item survey was sent to 20 US institutions that met inclusion criteria. The response rate was 100%. Seventeen institutions had a distinct transplant governance structure. A majority of respondents perceived that their type of transplant structure was associated with enhanced recognition within their institution (85%), improved regulatory compliance (85%), transplant volume growth (75%), improved quality outcomes (75%) and increased funding for transplant-related research (75%). The prevailing themes in respondents' remarks were the perceived need for autonomy of the transplant entity, alignment among services and finances and alignment of authority with responsibility. Many respondents suggested that a dialogue be opened about effective transplant infrastructure that overcomes the boundaries of traditional academic department silos.

  18. INCREASING SAVING BEHAVIOR THROUGH AGE-PROGRESSED RENDERINGS OF THE FUTURE SELF.

    Science.gov (United States)

    Hershfield, Hal E; Goldstein, Daniel G; Sharpe, William F; Fox, Jesse; Yeykelis, Leo; Carstensen, Laura L; Bailenson, Jeremy N

    2011-11-01

    Many people fail to save what they need to for retirement (Munnell, Webb, and Golub-Sass 2009). Research on excessive discounting of the future suggests that removing the lure of immediate rewards by pre-committing to decisions, or elaborating the value of future rewards can both make decisions more future-oriented. In this article, we explore a third and complementary route, one that deals not with present and future rewards, but with present and future selves. In line with thinkers who have suggested that people may fail, through a lack of belief or imagination, to identify with their future selves (Parfit 1971; Schelling 1984), we propose that allowing people to interact with age-progressed renderings of themselves will cause them to allocate more resources toward the future. In four studies, participants interacted with realistic computer renderings of their future selves using immersive virtual reality hardware and interactive decision aids. In all cases, those who interacted with virtual future selves exhibited an increased tendency to accept later monetary rewards over immediate ones.

  19. 6-DoF Haptic Rendering Using Continuous Collision Detection between Points and Signed Distance Fields.

    Science.gov (United States)

    Hongyi Xu; Barbic, Jernej

    2017-01-01

    We present an algorithm for fast continuous collision detection between points and signed distance fields, and demonstrate how to robustly use it for 6-DoF haptic rendering of contact between objects with complex geometry. Continuous collision detection is often needed in computer animation, haptics, and virtual reality applications, but has so far only been investigated for polygon (triangular) geometry representations. We demonstrate how to robustly and continuously detect intersections between points and level sets of the signed distance field. We suggest using an octree subdivision of the distance field for fast traversal of distance field cells. We also give a method to resolve continuous collisions between point clouds organized into a tree hierarchy and a signed distance field, enabling rendering of contact between rigid objects with complex geometry. We investigate and compare two 6-DoF haptic rendering methods now applicable to point-versus-distance field contact for the first time: continuous integration of penalty forces, and a constraint-based method. An experimental comparison to discrete collision detection demonstrates that the continuous method is more robust and can correctly resolve collisions even under high velocities and during complex contact.

  20. A predictive bone drilling force model for haptic rendering with experimental validation using fresh cadaveric bone.

    Science.gov (United States)

    Lin, Yanping; Chen, Huajiang; Yu, Dedong; Zhang, Ying; Yuan, Wen

    2017-01-01

    Bone drilling simulators with virtual and haptic feedback provide a safe, cost-effective and repeatable alternative to traditional surgical training methods. To develop such a simulator, accurate haptic rendering based on a force model is required to feedback bone drilling forces based on user input. Current predictive bone drilling force models based on bovine bones with various drilling conditions and parameters are not representative of the bone drilling process in bone surgery. The objective of this study was to provide a bone drilling force model for haptic rendering based on calibration and validation experiments in fresh cadaveric bones with different bone densities. Using a commonly used drill bit geometry (2 mm diameter), feed rates (20-60 mm/min) and spindle speeds (4000-6000 rpm) in orthognathic surgeries, the bone drilling forces of specimens from two groups were measured and the calibration coefficients of the specific normal and frictional pressures were determined. The comparison of the predicted forces and the measured forces from validation experiments with a large range of feed rates and spindle speeds demonstrates that the proposed bone drilling forces can predict the trends and average forces well. The presented bone drilling force model can be used for haptic rendering in surgical simulators.

  1. A proxy method for real-time 3-DOF haptic rendering of streaming point cloud data.

    Science.gov (United States)

    Rydén, Fredrik; Chizeck, Howard Jay

    2013-01-01

    This paper presents a new haptic rendering method for streaming point cloud data. It provides haptic rendering of moving physical objects using data obtained from RGB-D cameras. Thus, real-time haptic interaction with moving objects can be achieved using noncontact sensors. This method extends "virtual coupling"-based proxy methods in a way that does not require preprocessing of points and allows for spatial point cloud discontinuities. The key ideas of the algorithm are iterative motion of the proxy with respect to the points, and the use of a variable proxy step size that results in better accuracy for short proxy movements and faster convergence for longer movements. This method provides highly accurate haptic interaction for geometries in which the proxy can physically fit. Another advantage is a significant reduction in the risk of "pop through" during haptic interaction with dynamic point clouds, even in the presence of noise. This haptic rendering method is computationally efficient; it can run in real time on available personal computers without the need for downsampling of point clouds from commercially available depth cameras.

  2. A Fast Ambient Occlusion Method for Real-Time Plant Rendering

    Institute of Scientific and Technical Information of China (English)

    Jun Teng; Marc Jaeger; Bao-Gang HU

    2007-01-01

    Global illumination effects are crucial for virtual plant rendering. Whereas real-time global illumination rendering of plants is impractical, ambient occlusion is an efficient alternative approximation. A tree model with millions of triangles is common, and the triangles can be considered as randomly distributed. The existing ambient occlusion methods fail to apply on such a type of object. In this paper, we present a new ambient occlusion method dedicated to real time plant rendering with limited user interaction. This method is a three-step ambient occlusion calculation framework which is suitable for a huge number of geometry objects distributed randomly in space. The complexity of the proposed algorithm is O(n), compared to the conventional methods with complexities of O(n2). Furthermore, parameters in this method can be easily adjusted to achieve flexible ambient occlusion effects. With this ambient occlusion calculation method, we can manipulate plant models with millions of organs, as well as geometry objects with large number of randomly distributed components with affordable time, and with perceptual quality comparable to the previous ambient occlusion methods.

  3. The Role of Rendering in the Competence Project in Measurement Science for Optical Reflection and Scattering.

    Science.gov (United States)

    Westlund, Harold B; Meyer, Gary W; Hunt, Fern Y

    2002-01-01

    Computer rendering is used to simulate the appearance of lighted objects for applications in architectural design, for animation and simulation in the entertainment industry, and for display and design in the automobile industry. Rapid advances in computer graphics technology suggest that in the near future it will be possible to produce photorealistic images of coated surfaces from scattering data. This could enable the identification of important parameters in the coatings manufacturing process that lead to desirable appearance, and to the design of virtual surfaces by visualizing prospective coating formulations once their optical properties are known. Here we report the results of our work to produce visually and radiometrically accurate renderings of selected appearance attributes of sample coated surfaces. It required changes in the rendering programs, which in general are not designed to accept high quality optical and material measurements, and changes in the optical measurement protocols. An outcome of this research is that some current ASTM standards can be replaced or enhanced by computer based standards of appearance.

  4. Method of producing hydrogen, and rendering a contaminated biomass inert

    Science.gov (United States)

    Bingham, Dennis N [Idaho Falls, ID; Klingler, Kerry M [Idaho Falls, ID; Wilding, Bruce M [Idaho Falls, ID

    2010-02-23

    A method for rendering a contaminated biomass inert includes providing a first composition, providing a second composition, reacting the first and second compositions together to form an alkaline hydroxide, providing a contaminated biomass feedstock and reacting the alkaline hydroxide with the contaminated biomass feedstock to render the contaminated biomass feedstock inert and further producing hydrogen gas, and a byproduct that includes the first composition.

  5. 7 CFR 54.15 - Advance information concerning service rendered.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Advance information concerning service rendered. 54.15... Service § 54.15 Advance information concerning service rendered. Upon request of any applicant, all or any... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED)...

  6. Local and Global Illumination in the Volume Rendering Integral

    Energy Technology Data Exchange (ETDEWEB)

    Max, N; Chen, M

    2005-10-21

    This article is intended as an update of the major survey by Max [1] on optical models for direct volume rendering. It provides a brief overview of the subject scope covered by [1], and brings recent developments, such as new shadow algorithms and refraction rendering, into the perspective. In particular, we examine three fundamentals aspects of direct volume rendering, namely the volume rendering integral, local illumination models and global illumination models, in a wavelength-independent manner. We review the developments on spectral volume rendering, in which visible light are considered as a form of electromagnetic radiation, optical models are implemented in conjunction with representations of spectral power distribution. This survey can provide a basis for, and encourage, new efforts for developing and using complex illumination models to achieve better realism and perception through optical correctness.

  7. Perception-based transparency optimization for direct volume rendering.

    Science.gov (United States)

    Chan, Ming-Yuen; Wu, Yingcai; Mak, Wai-Ho; Chen, Wei; Qu, Huamin

    2009-01-01

    The semi-transparent nature of direct volume rendered images is useful to depict layered structures in a volume. However, obtaining a semi-transparent result with the layers clearly revealed is difficult and may involve tedious adjustment on opacity and other rendering parameters. Furthermore, the visual quality of layers also depends on various perceptual factors. In this paper, we propose an auto-correction method for enhancing the perceived quality of the semi-transparent layers in direct volume rendered images. We introduce a suite of new measures based on psychological principles to evaluate the perceptual quality of transparent structures in the rendered images. By optimizing rendering parameters within an adaptive and intuitive user interaction process, the quality of the images is enhanced such that specific user requirements can be met. Experimental results on various datasets demonstrate the effectiveness and robustness of our method.

  8. A Volume Rendering Algorithm for Sequential 2D Medical Images

    Institute of Scientific and Technical Information of China (English)

    吕忆松; 陈亚珠

    2002-01-01

    Volume rendering of 3D data sets composed of sequential 2D medical images has become an important branch in image processing and computer graphics.To help physicians fully understand deep-seated human organs and focuses(e.g.a tumour)as 3D structures.in this paper,we present a modified volume rendering algorithm to render volumetric data,Using this method.the projection images of structures of interest from different viewing directions can be obtained satisfactorily.By rotating the light source and the observer eyepoint,this method avoids rotates the whole volumetric data in main memory and thus reduces computational complexity and rendering time.Experiments on CT images suggest that the proposed method is useful and efficient for rendering 3D data sets.

  9. Redes sociales virtuales y la bioética

    OpenAIRE

    Pérez Pérez, Jorge Arturo

    2011-01-01

    This piece of research tends to inquire into the (obsessive) psychological, socio-family, physiological, and emotional conditions of the students at Saint Bonaventure University, Medellin Branch, back in the month of August 2010, who have the tendency to spend their free time in the Virtual Social Networks and then make an analysis of this issue, from the Bioethical viewpoint.

  10. Kepler Problem in Lagrangian Formulation Discussed from Topological Viewpoint

    Institute of Scientific and Technical Information of China (English)

    XU Gong-Ou; XU Ming-Jie

    2005-01-01

    @@ The Kepler problem in Lagrangian formulation is discussed from the topological viewpoint. Essential points are analysed. Along the same line of thoughts, it is possible to study the Kepler problem in Hamiltonian formulation as well as in quantum mechanics from the topological viewpoint for showing quantum-classical correspondence.

  11. Virtual Poetry.

    Science.gov (United States)

    Gyori, Ladislao Pablo

    1996-01-01

    Presents a manifesto proposing the creation of a new kind of poetry--virtual poetry--that exists only in electronic space and computer networks. States that this new poetry is interactive, animated, hyper-linked, and navigational. (PA)

  12. Virtual Exploratories

    DEFF Research Database (Denmark)

    Jensen, Sisse Siggaard

    2006-01-01

    This paper proposes the notion of activity-systems to denote a virtual frame of activity that requires mutually coordinated action. The underlying assumption is that such framings may support the informal learning and reflective practices of actors, and especially so, when they are provoking...... and challenging. It is suggested that the prevailing ‘traditions’ of collaborative learning and knowledge sharing need to be challenged and complemented, if we are to be able to support the variety and the diversity in the repertoires of virtual learning activities. In order to conceptualize such activity...... the design and activity of the advanced virtual worlds and role-playing games, then the empirical research on the actors’ activity, while they are acting, is an important precondition to it. A step towards the conception of such a designing strategy for virtual exploratories is currently pursued...

  13. Virtual Workshop

    DEFF Research Database (Denmark)

    Buus, Lillian; Bygholm, Ann

    In relation to the Tutor course in the Mediterranean Virtual University (MVU) project, a virtual workshop “Getting experiences with different synchronous communication media, collaboration, and group work” was held with all partner institutions in January 2006. More than 25 key-tutors within MVU...... participated from different institutions in the workshop. The result of the workshop was experiences with different communication tools and media. Facing the difficulties and possibilities in collaborateting virtually concerned around group work and development of a shared presentation. All based on getting...... experiences for the learning design of MVU courses. The workshop intented to give the participants the possibility to draw their own experiences with issues on computer supported collaboration, group work in a virtual environment, synchronous and asynchronous communication media, and different perspectives...

  14. Virtual Teams.

    Science.gov (United States)

    Geber, Beverly

    1995-01-01

    Virtual work teams scattered around the globe are becoming a feature of corporate workplaces. Although most people prefer face-to-face meetings and interactions, reality often requires telecommuting. (JOW)

  15. An Economic Viewpoint on Capitalism Bashing

    Directory of Open Access Journals (Sweden)

    Burnete Sorin

    2016-12-01

    Full Text Available In this paper I discuss two long disputed notions: that capitalism without crises is a fallacy respectively that capitalism bashing, however severe, will not endanger the system itself. Yet proving both is not an easy task since the capitalism issue has always been a cupellation of theory, ideology and political precepts, which are controversial and hard to disentangle. That capitalism detractors are numberless is a truism. Yet criticism against capitalism, however fierce, has always been clearly delineated. Not any more: globalization has rendered the picture dangerously fuzzy. It is now hard to ascertain whether someone who will harangue about the ostensible evils of globalization is also a declared anti-capitalist. The blend of capitalism and globalization seems to be pure dynamite.

  16. Virtual reality and virtual bodies

    Science.gov (United States)

    Richards, Catherine; Korba, Larry W.; Shaw, Christopher D.; Green, Mark

    1994-04-01

    There are many ways to produce the sense of `presence' or telepresence in the user of virtual reality. For example attempting to increase the realism of the visual environment is a commonly accepted strategy. In contrast, this paper explores a way for the user to feel present in an unrealistic virtual body. It investigates an unusual approach, proprioceptive illusions. Proprioceptive or body illusions are used to generate and explore the experience of virtuality and presence outside of the normal body limits. These projects are realized in art installations.

  17. QUALITY FROM THE VIEWPOINT OF TOURISM DESTINATION

    Directory of Open Access Journals (Sweden)

    Liliana ELMAZI

    2008-06-01

    Full Text Available Service quality initiatives are high priorities in many tourist destinations, with expenditure seen as long-term investment for future growth and profitability. My study’s goal is to explain the quality dimensions from the viewpoint of tourism destination. When we start to discuss about tourism quality supply, the main problem we have to consider is the structure of tourism supply as a complex of tangible and intangible elements. Analysis of the quality problem, their measuring and monitoring and marketing strategies based on quality, needs to be built on the specificity of tourist offer, regarding the level of goods and services. Because of this, the level of quality and customer satisfaction of quality is very hard to measure and to control. The first major feature of quality programs development is typically, to identify the key components or dimensions of quality from customer and employee research, i.e. their needs and expectations.

  18. Intuitive Experiences from Sohrevardi’s Viewpoint

    Directory of Open Access Journals (Sweden)

    Reza Heydarinoori

    2012-05-01

    Full Text Available The truth of intuitive experiences and how to fulfill them are among the issues that all people, cultures and rituals have faced with and expressed views about. There are two major approaches the essence-oriented notion which has emphasized on the cohesion and commonality of these experiences between individuals and people, and construction-oriented perspective which has considered more important roles for the discovery ideas and thoughts in the development and shaping of these experiences, so there are essential differences of them between people and cultures. Intellectual system of Illumination, which has been developed according to Sohrevardi’s discussions, has unique and valuable view in this regard. It asserts that :::::union::::: with light underlies mystical revelation and the specific self-centeredness is involved in the realization of these experiences along with illumination, observation, :::::union:::::, and inexistence. Although characteristics of illumination and talent are essential in this system of thought, the collection of features regarding spiritual experiences, according to Sohrevardi, represents a kind of essence-orientation in mystical revelation. The personal unity of experiences based on the thinking of each individual does not mean to separate experiences. Rather, they all have common grounds. The present study first, refers to the views expressed in this regard, and then explains what and how of spiritual experiences from the viewpoint of Sohrevardi. It finally, provides answers to some unknown issues.

  19. Intuitive Experiences from Sohrevardi’s Viewpoint

    Directory of Open Access Journals (Sweden)

    Heydarinoori, R

    2012-01-01

    Full Text Available The truth of intuitive experiences and how to fulfill them are among theissues that all people, cultures and rituals have faced with and expressedviews about. There are two major approaches; the essence-oriented notionwhich has emphasized on the cohesion and commonality of these experiencesbetween individuals and people, and construction-oriented perspective whichhas considered more important roles for the discovery ideas and thoughts inthe development and shaping of these experiences, so there are essentialdifferences of them between people and cultures. Intellectual system ofIllumination, which has been developed according to Sohrevardi’sdiscussions, has unique and valuable view in this regard. It asserts thatunion with light underlies mystical revelation and the specificself-centeredness is involved in the realization of these experiences alongwith illumination, observation, union, and inexistence. Althoughcharacteristics of illumination and talent are essential in this system ofthought, the collection of features regarding spiritual experiences,according to Sohrevardi, represents a kind of essence-orientation inmystical revelation. The personal unity of experiences based on thethinking of each individual does not mean to separate experiences. Rather,they all have common grounds. The present study first, refers to the viewsexpressed in this regard, and then explains what and how of spiritualexperiences from the viewpoint of Sohrevardi. It finally, provides answersto some unknown issues.

  20. Virtual Specimens

    Science.gov (United States)

    de Paor, D. G.

    2009-12-01

    Virtual Field Trips have been around almost as long as the Worldwide Web itself yet virtual explorers do not generally return to their desktops with folders full of virtual hand specimens. Collection of real specimens on fields trips for later analysis in the lab (or at least in the pub) has been an important part of classical field geoscience education and research for generations but concern for the landscape and for preservation of key outcrops from wanton destruction has lead to many restrictions. One of the author’s favorite outcrops was recently vandalized presumably by a geologist who felt the need to bash some of the world’s most spectacular buckle folds with a rock sledge. It is not surprising, therefore, that geologists sometimes leave fragile localities out of field trip itineraries. Once analyzed, most specimens repose in drawers or bins, never to be seen again. Some end up in teaching collections but recent pedagogical research shows that undergraduate students have difficulty relating specimens both to their collection location and ultimate provenance in the lithosphere. Virtual specimens can be created using 3D modeling software and imported into virtual globes such as Google Earth (GE) where, they may be linked to virtual field trip stops or restored to their source localities on the paleo-globe. Sensitive localities may be protected by placemark approximation. The GE application program interface (API) has a distinct advantage over the stand-alone GE application when it comes to viewing and manipulating virtual specimens. When instances of the virtual globe are embedded in web pages using the GE plug-in, Collada models of specimens can be manipulated with javascript controls residing in the enclosing HTML, permitting specimens to be magnified, rotated in 3D, and sliced. Associated analytical data may be linked into javascript and localities for comparison at various points on the globe referenced by ‘fetching’ KML. Virtual specimens open up

  1. Virtualization of work in global supply chains

    Directory of Open Access Journals (Sweden)

    Sabina Wyrwich-Płotka

    2016-12-01

    Full Text Available Background: The paper is devoted to the notion and benefits of implementing virtual work in global supply chains. Virtual work must be understood as an intentional activity of a human being, aimed at rendering services (tangible and intangible, by means of ITC tools, performed in a distance from the traditional place of work, in a mobile manner. The empirical research were conducted on the basis of 4 case studies of global leaders of supply chains, which in accordance with M. Fisher's classification, represent two types. The case studies confirmed the positive influence of virtual work both in effective and flexible supply chains. Favourable market and technological conditions and increasing awareness of benefits of virtual work will make it more and more widespread in companies comprising global supply chains. The aim of the study is to demonstrate the cause and effect relationships between virtual work and competitiveness of efficient and flexible supply chain. Methods: The paper is based on the available recent scientific-theoretical research and publication.  The authors analyzed 4 enterprises in Poland. The enterprises representing a flexible or an effective supply chain, either using or not a virtual work. The study carried out the authors had the form of individual interviews. The authors used case studies to show that virtual work brings notable benefits in an effective and flexible supply chain.  Results: Based on these case studies, the authors demonstrated reasons to implement virtual work in selected enterprises. The reasons to implement virtual work are determinants of possible achieve economies in effective and flexible supply chain Conclusions: The examined case studies show that virtual work brings different benefits. In the effective supply chain, virtual workers enable to increase effectiveness and financial results for example. In the flexible supply chain the virtual work can be a way to maintain and build long

  2. Virtual instrumentation: Introduction of virtual

    OpenAIRE

    Ödlund, Erika

    2007-01-01

    The Large Hadron Collider (LHC) is the next large particle accelerator developed at CERN, constructed to enable studies of particles. The acceleration of the particles is carried out using magnets operating at about 1.9 K, a temperature achieved by regulating flow of superfluid helium. For economical reasons, control of the helium flow is based on feedback of virtual flow meter (VFT) estimates instead of real instrumentation. The main purpose of this work is to develop a virtual flow meter wi...

  3. Multiresolution maximum intensity volume rendering by morphological adjunction pyramids

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.

    We describe a multiresolution extension to maximum intensity projection (MIP) volume rendering, allowing progressive refinement and perfect reconstruction. The method makes use of morphological adjunction pyramids. The pyramidal analysis and synthesis operators are composed of morphological 3-D

  4. Multiresolution Maximum Intensity Volume Rendering by Morphological Adjunction Pyramids

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.

    2001-01-01

    We describe a multiresolution extension to maximum intensity projection (MIP) volume rendering, allowing progressive refinement and perfect reconstruction. The method makes use of morphological adjunction pyramids. The pyramidal analysis and synthesis operators are composed of morphological 3-D

  5. Comparison of Morphological Pyramids for Multiresolution MIP Volume Rendering

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.

    2002-01-01

    We recently proposed a multiresolution representation for maximum intensity projection (MIP) volume rendering based on morphological adjunction pyramids which allow progressive refinement and have the property of perfect reconstruction. In this algorithm the pyramidal analysis and synthesis

  6. Experiencing "Macbeth": From Text Rendering to Multicultural Performance.

    Science.gov (United States)

    Reisin, Gail

    1993-01-01

    Shows how one teacher used innovative methods in teaching William Shakespeare's "Macbeth." Outlines student assignments including text renderings, rewriting a scene from the play, and creating a multicultural scrapbook for the play. (HB)

  7. High-quality multi-resolution volume rendering in medicine

    Institute of Scientific and Technical Information of China (English)

    XIE Kai; YANG Jie; LI Xiao-liang

    2007-01-01

    In order to perform a high-quality interactive rendering of large medical data sets on a single off-theshelf PC, a LOD selection algorithm for multi-resolution volume rendering using 3D texture mapping is presented, which uses an adaptive scheme that renders the volume in a region-of-interest at a high resolution and the volume away from this region at lower resolutions. The algorithm is based on several important criteria, and rendering is done adaptively by selecting high-resolution cells close to a center of attention and low-resolution cells away from this area. In addition, our hierarchical level-of-detail representation guarantees consistent interpolation between different resolution levels. Experiments have been applied to a number of large medical data and have produced high quality images at interactive frame rates using standard PC hardware.

  8. Factors affecting extension workers in their rendering of effective ...

    African Journals Online (AJOL)

    Factors affecting extension workers in their rendering of effective service to pre ... the objective of achieving sustainable livelihoods for the poor and commonages. ... marketing and management to adequately service the land reform programs.

  9. does knowledge influence their attitude and comfort in rendering care?

    African Journals Online (AJOL)

    kemrilib

    Physicians and AIDS care: does knowledge influence their attitude and comfort in rendering ... experience, age and being a consultant or a senior resident influenced attitude, while male ..... having or not having children, prior instructions on ...

  10. Accelerating Monte Carlo Renderers by Ray Histogram Fusion

    Directory of Open Access Journals (Sweden)

    Mauricio Delbracio

    2015-03-01

    Full Text Available This paper details the recently introduced Ray Histogram Fusion (RHF filter for accelerating Monte Carlo renderers [M. Delbracio et al., Boosting Monte Carlo Rendering by Ray Histogram Fusion, ACM Transactions on Graphics, 33 (2014]. In this filter, each pixel in the image is characterized by the colors of the rays that reach its surface. Pixels are compared using a statistical distance on the associated ray color distributions. Based on this distance, it decides whether two pixels can share their rays or not. The RHF filter is consistent: as the number of samples increases, more evidence is required to average two pixels. The algorithm provides a significant gain in PSNR, or equivalently accelerates the rendering process by using many fewer Monte Carlo samples without observable bias. Since the RHF filter depends only on the Monte Carlo samples color values, it can be naturally combined with all rendering effects.

  11. A parallel architecture for interactively rendering scattering and refraction effects.

    Science.gov (United States)

    Bernabei, Daniele; Hakke-Patil, Ajit; Banterle, Francesco; Di Benedetto, Marco; Ganovelli, Fabio; Pattanaik, Sumanta; Scopigno, Roberto

    2012-01-01

    A new method for interactive rendering of complex lighting effects combines two algorithms. The first performs accurate ray tracing in heterogeneous refractive media to compute high-frequency phenomena. The second applies lattice-Boltzmann lighting to account for low-frequency multiple-scattering effects. The two algorithms execute in parallel on modern graphics hardware. This article includes a video animation of the authors' real-time algorithm rendering a variety of scenes.

  12. Wavelet subdivision methods gems for rendering curves and surfaces

    CERN Document Server

    Chui, Charles

    2010-01-01

    OVERVIEW Curve representation and drawing Free-form parametric curves From subdivision to basis functions Wavelet subdivision and editing Surface subdivision BASIS FUNCTIONS FOR CURVE REPRESENTATION Refinability and scaling functions Generation of smooth basis functions Cardinal B-splines Stable bases for integer-shift spaces Splines and polynomial reproduction CURVE SUBDIVISION SCHEMES Subdivision matrices and stencils B-spline subdivision schemes Closed curve rendering Open curve rendering BASIS FUNCTIONS GENERATED BY SUBDIVISION MATRICES Subdivision operators The up-sampling convolution ope

  13. Sound Synthesis and Evaluation of Interactive Footsteps and Environmental Sounds Rendering for Virtual Reality Applications

    DEFF Research Database (Denmark)

    Nordahl, Rolf; Turchet, Luca; Serafin, Stefania

    2011-01-01

    We propose a system that affords real-time sound synthesis of footsteps on different materials. The system is based on microphones, which detect real footstep sounds from subjects, from which the ground reaction force (GRF) is estimated. Such GRF is used to control a sound synthesis engine based ...

  14. A Sort-Last Rendering System over an Optical Backplane

    Directory of Open Access Journals (Sweden)

    Yasuhiro Kirihata

    2005-06-01

    Full Text Available Sort-Last is a computer graphics technique for rendering extremely large data sets on clusters of computers. Sort-Last works by dividing the data set into even-sized chunks for parallel rendering and then composing the images to form the final result. Since sort-last rendering requires the movement of large amounts of image data among cluster nodes, the network interconnecting the nodes becomes a major bottleneck. In this paper, we describe a sort-last rendering system implemented on a cluster of computers whose nodes are connected by an all-optical switch. The rendering system introduces the notion of the Photonic Computing Engine, a computing system built dynamically by using the optical switch to create dedicated network connections among cluster nodes. The sort-last volume rendering algorithm was implemented on the Photonic Computing Engine, and its performance is evaluated. Prelimi- nary experiments show that performance is affected by the image composition time and average payload size. In an attempt to stabilize the performance of the system, we have designed a flow control mechanism that uses feedback messages to dynamically adjust the data flow rate within the computing engine.

  15. Remote volume rendering pipeline for mHealth applications

    Science.gov (United States)

    Gutenko, Ievgeniia; Petkov, Kaloian; Papadopoulos, Charilaos; Zhao, Xin; Park, Ji Hwan; Kaufman, Arie; Cha, Ronald

    2014-03-01

    We introduce a novel remote volume rendering pipeline for medical visualization targeted for mHealth (mobile health) applications. The necessity of such a pipeline stems from the large size of the medical imaging data produced by current CT and MRI scanners with respect to the complexity of the volumetric rendering algorithms. For example, the resolution of typical CT Angiography (CTA) data easily reaches 512^3 voxels and can exceed 6 gigabytes in size by spanning over the time domain while capturing a beating heart. This explosion in data size makes data transfers to mobile devices challenging, and even when the transfer problem is resolved the rendering performance of the device still remains a bottleneck. To deal with this issue, we propose a thin-client architecture, where the entirety of the data resides on a remote server where the image is rendered and then streamed to the client mobile device. We utilize the display and interaction capabilities of the mobile device, while performing interactive volume rendering on a server capable of handling large datasets. Specifically, upon user interaction the volume is rendered on the server and encoded into an H.264 video stream. H.264 is ubiquitously hardware accelerated, resulting in faster compression and lower power requirements. The choice of low-latency CPU- and GPU-based encoders is particularly important in enabling the interactive nature of our system. We demonstrate a prototype of our framework using various medical datasets on commodity tablet devices.

  16. Fast DRR splat rendering using common consumer graphics hardware.

    Science.gov (United States)

    Spoerk, Jakob; Bergmann, Helmar; Wanschitz, Felix; Dong, Shuo; Birkfellner, Wolfgang

    2007-11-01

    Digitally rendered radiographs (DRR) are a vital part of various medical image processing applications such as 2D/3D registration for patient pose determination in image-guided radiotherapy procedures. This paper presents a technique to accelerate DRR creation by using conventional graphics hardware for the rendering process. DRR computation itself is done by an efficient volume rendering method named wobbled splatting. For programming the graphics hardware, NVIDIAs C for Graphics (Cg) is used. The description of an algorithm used for rendering DRRs on the graphics hardware is presented, together with a benchmark comparing this technique to a CPU-based wobbled splatting program. Results show a reduction of rendering time by about 70%-90% depending on the amount of data. For instance, rendering a volume of 2 x 10(6) voxels is feasible at an update rate of 38 Hz compared to 6 Hz on a common Intel-based PC using the graphics processing unit (GPU) of a conventional graphics adapter. In addition, wobbled splatting using graphics hardware for DRR computation provides higher resolution DRRs with comparable image quality due to special processing characteristics of the GPU. We conclude that DRR generation on common graphics hardware using the freely available Cg environment is a major step toward 2D/3D registration in clinical routine.

  17. Easy and effective virtual tour on the World Wide Web

    Science.gov (United States)

    Yoon, Ilmi; Kang, Andrew; Roberts, John; Yoon, Sanghyuk

    2005-01-01

    Web-based Virtual Tour has become a desirable and demanded application, yet challenging due to the nature of web application's running environment such as limited bandwidth and no guarantee of high computation power on the client side. Image-based rendering approach has attractive advantages over traditional 3D rendering approach in such Web Applications. Traditional geometry-based approach, such as VRML, requires labor-intensive 3D modeling process, high bandwidth and computation power especially for photo-realistic virtual scenes. QuickTime VR and IPIX as examples of image-based approach, use panoramic photos and the virtual scenes that can be generated from photos directly skipping the modeling process. But, QuickTime VR and IPIX may not only require special cameras or effort to take panoramic views but also provide only one fixed-point navigation (look-around and zooming in-out) rather than "walk around", that is a very important feature to provide immersive experience to virtual tourists. Easy and Effective Virtual Tour constructs virtual tour using several snap shots of conventional photos without special tools, build simple 3D space within each photo using spidery mesh, and expand the virtual spaces by connecting each other using simple user intervention to specify correspondence. The expanded virtual space provides virtual tourists with free navigation and immersive experience of walking around through the WWW.

  18. Viewpoints: a framework for object oriented database modelling and distribution

    Directory of Open Access Journals (Sweden)

    Fouzia Benchikha

    2006-01-01

    Full Text Available The viewpoint concept has received widespread attention recently. Its integration into a data model improves the flexibility of the conventional object-oriented data model and allows one to improve the modelling power of objects. The viewpoint paradigm can be used as a means of providing multiple descriptions of an object and as a means of mastering the complexity of current database systems enabling them to be developed in a distributed manner. The contribution of this paper is twofold: to define an object data model integrating viewpoints in databases and to present a federated database system integrating multiple sources following a local-as-extended-view approach.

  19. Virtual Reality for Training and Lifelong Learning

    Directory of Open Access Journals (Sweden)

    Daniel Mellet-d'Huart

    2009-01-01

    Full Text Available This article covers the application of virtual reality (VR to training and lifelong learning. A number of considerations concerning the design of VR applications are included. The introduction is dedicated to the more general aspects of applying VR to training. From multiple perspectives, we will provide an overview of existing applications with their main purposes and go into more depth on certain learning areas. Recent developments of virtual environments for training and lifelong learning are analyzed, followed by an analytical viewpoint on design, advocating more explicit paradigmatic considerations and development of generic design methods. These approaches and proposals are aimed at better exploiting the uniqueness of VR and designing more effective virtual environments. Finally, a number of conclusions will be drawn for future technology-enhanced training and for lifelong learning using VR.

  20. Virtual care

    DEFF Research Database (Denmark)

    Kamp, Annette; Aaløkke Ballegaard, Stinne

    point out how issues of trust and surveillance, which are always negotiated in care relations, are in fact accentuated in this kind of virtual care work. Moreover, we stress that the contemporary institutional context, organization and time schedules have a vast impact on the practices developed....... of retrenchment, promising better quality, empowerment of citizens and work that is smarter and more qualified. Through ethnographic field studies we study the introduction of virtual home care in Danish elderly care, focusing on the implications for relational work and care relations. Virtual home care entails...... the performance of specific home care services by means of video conversations rather than physical visits in the citizens’ homes. As scholars within the STS tradition maintain, technologies do not simply replace a human function; they rather transform care work, redistributing tasks between citizens, technology...

  1. Virtual Tower

    Energy Technology Data Exchange (ETDEWEB)

    Wayne, R.A. [Sandia National Labs., Albuquerque, NM (United States). Security Engineering Dept.

    1997-08-01

    The primary responsibility of an intrusion detection system (IDS) operator is to monitor the system, assess alarms, and summon and coordinate the response team when a threat is acknowledged. The tools currently provided to the operator are somewhat limited: monitors must be switched, keystrokes must be entered to call up intrusion sensor data, and communication with the response force must be maintained. The Virtual tower is an operator interface assembled from low-cost commercial-off-the-shelf hardware and software; it enables large amounts of data to be displayed in a virtual manner that provides instant recognition for the operator and increases assessment accuracy in alarm annunciator and control systems. This is accomplished by correlating and fusing the data into a 360-degree visual representation that employs color, auxiliary attributes, video, and directional audio to prompt the operator. The Virtual Tower would be a valuable low-cost enhancement to existing systems.

  2. Virtual Violence.

    Science.gov (United States)

    2016-08-01

    In the United States, exposure to media violence is becoming an inescapable component of children's lives. With the rise in new technologies, such as tablets and new gaming platforms, children and adolescents increasingly are exposed to what is known as "virtual violence." This form of violence is not experienced physically; rather, it is experienced in realistic ways via new technology and ever more intense and realistic games. The American Academy of Pediatrics continues to be concerned about children's exposure to virtual violence and the effect it has on their overall health and well-being. This policy statement aims to summarize the current state of scientific knowledge regarding the effects of virtual violence on children's attitudes and behaviors and to make specific recommendations for pediatricians, parents, industry, and policy makers.

  3. Virtual Sustainability

    Directory of Open Access Journals (Sweden)

    William Sims Bainbridge

    2010-09-01

    Full Text Available In four ways, massively multiplayer online role-playing games may serve as tools for advancing sustainability goals, and as laboratories for developing alternatives to current social arrangements that have implications for the natural environment. First, by moving conspicuous consumption and other usually costly status competitions into virtual environments, these virtual worlds might reduce the need for physical resources. Second, they provide training that could prepare individuals to be teleworkers, and develop or demonstrate methods for using information technology to replace much transportation technology, notably in commuting. Third, virtual worlds and online games build international cooperation, even blending national cultures, thereby inching us toward not only the world consciousness needed for international agreements about the environment, but also toward non-spatial government that cuts across archaic nationalisms. Finally, realizing the potential social benefits of this new technology may urge us to reconsider a number of traditional societal institutions.

  4. Virtual Classroom

    DEFF Research Database (Denmark)

    Christensen, Ove

    2013-01-01

    In the Scandinavian countries: Sweden, Norway and Denmark, the project GNU (Grænseoverskridende Nordisk Undervisning, i.e. Transnational Nordic Teaching) is experimenting with ways of conducting teaching across the borders in the elementary schools. The cloud classes are organised with one class ...... and benefits in regard to learning and pedagogy with virtual classroom....

  5. Virtual Savannah

    DEFF Research Database (Denmark)

    Rodil, Kasper; Eskildsen, Søren; Rehm, Matthias

    2012-01-01

    Virtual Savannah is constructed to visualize parts of a curriculum, which the educational service at Aalborg Zoo has difficulties in teaching children visiting the zoo. It contains rich media like audio, text, video and picture galleries about African ecology, but some of this episodic information...

  6. Virtual landmarks

    Science.gov (United States)

    Tong, Yubing; Udupa, Jayaram K.; Odhner, Dewey; Bai, Peirui; Torigian, Drew A.

    2017-03-01

    Much has been published on finding landmarks on object surfaces in the context of shape modeling. While this is still an open problem, many of the challenges of past approaches can be overcome by removing the restriction that landmarks must be on the object surface. The virtual landmarks we propose may reside inside, on the boundary of, or outside the object and are tethered to the object. Our solution is straightforward, simple, and recursive in nature, proceeding from global features initially to local features in later levels to detect landmarks. Principal component analysis (PCA) is used as an engine to recursively subdivide the object region. The object itself may be represented in binary or fuzzy form or with gray values. The method is illustrated in 3D space (although it generalizes readily to spaces of any dimensionality) on four objects (liver, trachea and bronchi, and outer boundaries of left and right lungs along pleura) derived from 5 patient computed tomography (CT) image data sets of the thorax and abdomen. The virtual landmark identification approach seems to work well on different structures in different subjects and seems to detect landmarks that are homologously located in different samples of the same object. The approach guarantees that virtual landmarks are invariant to translation, scaling, and rotation of the object/image. Landmarking techniques are fundamental for many computer vision and image processing applications, and we are currently exploring the use virtual landmarks in automatic anatomy recognition and object analytics.

  7. Virtual Expo

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The online version of the 2010 Shanghai Expo shows the future glory The 2010 Shanghai Expo is now open and letting visitors explore almost all its pavilions and exhib-its-virtually. The website for the World Expo launched on November 12,

  8. Virtual Savannah

    DEFF Research Database (Denmark)

    Rodil, Kasper; Eskildsen, Søren; Rehm, Matthias

    2012-01-01

    Virtual Savannah is constructed to visualize parts of a curriculum, which the educational service at Aalborg Zoo has difficulties in teaching children visiting the zoo. It contains rich media like audio, text, video and picture galleries about African ecology, but some of this episodic information...

  9. Virtual patrolling

    NARCIS (Netherlands)

    Vlist, van der M.; Wismans, L.J.J.; Beek, van P.; Suijs, L.C.W.

    2016-01-01

    Approximately 25 per cent of all congestion on motorways is caused by incidents. By virtual patrolling, incidents e.g. queues, accidents and car breakdowns on a road network, can be predicted or detected in an early stage. This early detection and prediction of an incident likely to happen, offers t

  10. Virtual Reality.

    Science.gov (United States)

    Newby, Gregory B.

    1993-01-01

    Discusses the current state of the art in virtual reality (VR), its historical background, and future possibilities. Highlights include applications in medicine, art and entertainment, science, business, and telerobotics; and VR for information science, including graphical display of bibliographic data, libraries and books, and cyberspace.…

  11. Virtually There.

    Science.gov (United States)

    Lanier, Jaron

    2001-01-01

    Describes tele-immersion, a new medium for human interaction enabled by digital technologies. It combines the display and interaction techniques of virtual reality with new vision technologies that transcend the traditional limitations of a camera. Tele-immersion stations observe people as moving sculptures without favoring a single point of view.…

  12. Virtual Savannah

    DEFF Research Database (Denmark)

    Eskildsen, Søren; Rodil, Kasper; Rehm, Matthias

    2012-01-01

    and the navigation. The test depicted how they managed to search the virtual world for answers in patterns related to restrictions in the system and using graphical points of interest as reference points. Collecting information about the complete interaction provides teachers with a tool to assess the individual...

  13. Rendering graphene supports hydrophilic with non-covalent aromatic functionalization for transmission electron microscopy

    Science.gov (United States)

    Pantelic, Radosav S.; Fu, Wangyang; Schoenenberger, Christian; Stahlberg, Henning

    2014-03-01

    Amorphous carbon films have been routinely used to enhance the preparation of frozen-hydrated samples for transmission electron microscopy (TEM), either in retaining protein concentration, providing mechanical stability or dissipating sample charge. However, strong background signal from the amorphous carbon support obstructs that of the sample, and the insulating properties of thin amorphous carbon films preclude any efficiency in dispersing charge. Graphene addresses the limitations of amorphous carbon. Graphene is a crystalline material with virtually no phase or amplitude contrast and unparalleled, high electrical carrier mobility. However, the hydrophobic properties of graphene have prevented its routine application in Cryo-TEM. This Letter reports a method for rendering graphene TEM supports hydrophilic—a convenient approach maintaining graphene's structural and electrical properties based on non-covalent, aromatic functionalization.

  14. Rendering graphene supports hydrophilic with non-covalent aromatic functionalization for transmission electron microscopy

    CERN Document Server

    Pantelic, Radosav S; Schoenenberger, Christian; Stahlberg, Henning

    2014-01-01

    Amorphous carbon films have been routinely used to enhance the preparation of frozen-hydrated transmission electron microscopy (TEM) samples, either in retaining protein concentration, providing mechanical stability or dissipating sample charge. However, strong background signal from the amorphous carbon support obstructs that of the sample, and the insulating properties of amorphous carbon films preclude any efficiency in dispersing charge. Graphene addresses the limitations of amorphous carbon. Graphene is a crystalline material with virtually no phase or amplitude contrast and unparalleled, high electrical carrier mobility. However, the hydrophobic properties of graphene have prevented its routine application in Cryo-TEM. This letter reports a method for rendering graphene TEM supports hydrophilic - a convenient approach maintaining graphene's structural and electrical properties based on non-covalent, aromatic functionalization.

  15. High resolution renderings and interactive visualization of the 2006 Huntington Beach experiment

    Science.gov (United States)

    Im, T.; Nayak, A.; Keen, C.; Samilo, D.; Matthews, J.

    2006-12-01

    The Visualization Center at the Scripps Institution of Oceanography investigates innovative ways to represent graphically interactive 3D virtual landscapes and to produce high resolution, high quality renderings of Earth sciences data and the sensors and instruments used to collect the data . Among the Visualization Center's most recent work is the visualization of the Huntington Beach experiment, a study launched in July 2006 by the Southern California Ocean Observing System (http://www.sccoos.org/) to record and synthesize data of the Huntington Beach coastal region. Researchers and students at the Visualization Center created visual presentations that combine bathymetric data provided by SCCOOS with USGS aerial photography and with 3D polygonal models of sensors created in Maya into an interactive 3D scene using the Fledermaus suite of visualization tools (http://www.ivs3d.com). In addition, the Visualization Center has produced high definition (HD) animations of SCCOOS sensor instruments (e.g. REMUS, drifters, spray glider, nearshore mooring, OCSD/USGS mooring and CDIP mooring) using the Maya modeling and animation software and rendered over multiple nodes of the OptIPuter Visualization Cluster at Scripps. These visualizations are aimed at providing researchers with a broader context of sensor locations relative to geologic characteristics, to promote their use as an educational resource for informal education settings and increasing public awareness, and also as an aid for researchers' proposals and presentations. These visualizations are available for download on the Visualization Center website at http://siovizcenter.ucsd.edu/sccoos/hb2006.php.

  16. Development of Virtual Equipment for a Hydraulic Mechanics Experiment

    Institute of Scientific and Technical Information of China (English)

    CHAN Ying-Chieh; CHEN Ya-Hsin; KANG Shih-Chung; LEE Tim-Hau

    2008-01-01

    Laboratory class is very important in the education of hydraulic mechanics. However, it usually requires a high expenditure on equipment purchase and maintenance. Virtual equipment that renders the equipment in a virtual world and provides an interactive interface for users can be an ideal solution to reduce costs. In this research, we focus on developing virtual equipment for a Venturi tube experiment. We em-ployed multiple paper-prototypes to gather user feedback on the preliminary design. Following the final pro-totype, we then implemented the virtual equipment on computers. Interactive functions have been built into the virtual equipment. Users are able to manipulate the equipment and obtain real-time feedback as if they were using actual equipment. The results show that the development of the virtual equipment is technically feasible.

  17. Current viewpoints on DSM-5 in Japan.

    Science.gov (United States)

    Kuroki, Toshihide; Ishitobi, Makoto; Kamio, Yoko; Sugihara, Genichi; Murai, Toshiya; Motomura, Keisuke; Ogasawara, Kazuyoshi; Kimura, Hiroyuki; Aleksic, Branko; Ozaki, Norio; Nakao, Tomohiro; Yamada, Kazuo; Yoshiuchi, Kazuhiro; Kiriike, Nobuo; Ishikawa, Toshio; Kubo, Chiharu; Matsunaga, Chiaki; Miyata, Hisatsugu; Asada, Takashi; Kanba, Shigenobu

    2016-09-01

    The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) was published in 2013, and its official Japanese version was published in 2014. The Japanese Government uses classifications from the 10th revision of the I nternational C lassification of D iseases (ICD-10) to categorize disorders and determine treatment fees. However, since the publication of the DSM-III, the use of the DSM system has become prevalent in research and educational settings in Japan. In addition to traditional psychiatry, both the ICD and the DSM are taught by many Japanese medical schools, and virtually all clinical research and trials refer to the DSM to define targeted disorders. Amid the current backdrop in which the reputation of the DSM-5 is being established, the editorial board of P sychiatry and C linical N eurosciences has asked Japanese experts across 12 specialties to examine the structure of the DSM-5, including the following categories: Neurodevelopmental Disorders, Schizophrenia Spectrum Disorders, Major Depression, Bipolar Disorders, Obsessive-Compulsive Disorders, Somatic Symptom Disorder, Eating Disorders, Substance-Related and Addictive Disorders, Gender Dysphoria, and Neurocognitive Disorders. Although opinions were only obtained from these selected experts, we believe that we have succeeded, to a certain extent, in presenting views that are representative of each specialty. © 2016 The Authors. Psychiatry and Clinical Neurosciences © 2016 Japanese Society of Psychiatry and Neurology.

  18. A Study of Power and Individualism in Virtual Teams: Trends, Challenges, and Solutions

    Science.gov (United States)

    Jablonski, Deirdre

    2013-01-01

    This study investigated the relationship between cultural values and effectiveness of virtual team processes. In order to render an acceptable degree of comparison, four specific team outcomes of virtual team effectiveness were aligned on Hofstede's cultural dimensions of power distance and individualism. The lack of awareness of how power and…

  19. Clustered deep shadow maps for integrated polyhedral and volume rendering

    KAUST Repository

    Bornik, Alexander

    2012-01-01

    This paper presents a hardware-accelerated approach for shadow computation in scenes containing both complex volumetric objects and polyhedral models. Our system is the first hardware accelerated complete implementation of deep shadow maps, which unifies the computation of volumetric and geometric shadows. Up to now such unified computation was limited to software-only rendering . Previous hardware accelerated techniques can handle only geometric or only volumetric scenes - both resulting in the loss of important properties of the original concept. Our approach supports interactive rendering of polyhedrally bounded volumetric objects on the GPU based on ray casting. The ray casting can be conveniently used for both the shadow map computation and the rendering. We show how anti-aliased high-quality shadows are feasible in scenes composed of multiple overlapping translucent objects, and how sparse scenes can be handled efficiently using clustered deep shadow maps. © 2012 Springer-Verlag.

  20. Real-Time Rendering of Teeth with No Preprocessing

    DEFF Research Database (Denmark)

    Larsen, Christian Thode; Frisvad, Jeppe Revall; Jensen, Peter Dahl Ejby

    2012-01-01

    We present a technique for real-time rendering of teeth with no need for computational or artistic preprocessing. Teeth constitute a translucent material consisting of several layers; a highly scattering material (dentine) beneath a semitransparent layer (enamel) with a transparent coating (saliva......). In this study we examine how light interacts with this multilayered structure. In the past, rendering of teeth has mostly been done using image-based texturing or volumetric scans. We work with surface scans and have therefore developed a simple way of estimating layer thicknesses. We use scattering properties...... based on measurements reported in the optics literature, and we compare rendered results qualitatively to images of ceramic teeth created by denturists....

  1. [A hybrid volume rendering method using general hardware].

    Science.gov (United States)

    Li, Bin; Tian, Lianfang; Chen, Ping; Mao, Zongyuan

    2008-06-01

    In order to improve the effect and efficiency of the reconstructed image after hybrid volume rendering of different kinds of volume data from medical sequential slices or polygonal models, we propose a hybrid volume rendering method based on Shear-Warp with economical hardware. First, the hybrid volume data are pre-processed by Z-Buffer method and RLE (Run-Length Encoded) data structure. Then, during the process of compositing intermediate image, a resampling method based on the dual-interpolation and the intermediate slice interpolation methods is used to improve the efficiency and the effect. Finally, the reconstructed image is rendered by the texture-mapping technology of OpenGL. Experiments demonstrate the good performance of the proposed method.

  2. Universal Rendering Mechanism Supporting Dual-Mode Presentation

    Institute of Scientific and Technical Information of China (English)

    徐鹏; 杨文军; 王克宏

    2003-01-01

    XML is a standard for the exchange of business data that is completely platform and vendor neutral. Because XML data comes in many forms, one of the most important technologies needed for XML applications is the ability to convert the data into visible renderings. This paper focuses on the rendering of XML/XSL documents into a readable and printable format by means of a platform-independent process that enables high-quality printing of the product. This paper introduces the core components in the data rendering engine, the X2P server and different levels of object abstraction. The design pattern and the complete formatting and representation of the XSL stylesheet into different types of output formats in the X2P server are also given. The results show that the X2P sever simultaneously constructs the formatting object tree and the area tree in a very efficient design that saves execution time and memory.

  3. Efficient rendering of breaking waves using MPS method

    Institute of Scientific and Technical Information of China (English)

    WANG Qiang; ZHENG Yao; CHEN Chun; FUJIMOTO Tadahiro; CHIBA Norishige

    2006-01-01

    This paper proposes an approach for rendering breaking waves out of large-scale ofparticle-based simulation. Moving particle semi-implicit (MPS) is used to solve the governing equation, and 2D simulation is expanded to 3D representation by giving motion variation using fractional Brownian motion (fBm). The waterbody surface is reconstructed from the outlines of 2D simulation. The splashing effect is computed according to the properties of the particles. Realistic features of the wave are rendered on GPU, including the reflective and refractive effect and the effect of splash. Experiments showed that the proposed method can simulate large scale breaking waves efficiently.

  4. Beaming teaching application: recording techniques for spatial xylophone sound rendering

    DEFF Research Database (Denmark)

    Markovic, Milos; Madsen, Esben; Olesen, Søren Krarup;

    2012-01-01

    BEAMING is a telepresence research project aiming at providing a multimodal interaction between two or more participants located at distant locations. One of the BEAMING applications allows a distant teacher to give a xylophone playing lecture to the students. Therefore, rendering of the xylophone...... played at student's location is required at teacher's site. This paper presents a comparison of different recording techniques for a spatial xylophone sound rendering. Directivity pattern of the xylophone was measured and spatial properties of the sound field created by a xylophone as a distributed sound...

  5. Chromium Renderserver: Scalable and Open Source Remote RenderingInfrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Brian; Ahern, Sean; Bethel, E. Wes; Brugger, Eric; Cook,Rich; Daniel, Jamison; Lewis, Ken; Owen, Jens; Southard, Dale

    2007-12-01

    Chromium Renderserver (CRRS) is software infrastructure thatprovides the ability for one or more users to run and view image outputfrom unmodified, interactive OpenGL and X11 applications on a remote,parallel computational platform equipped with graphics hardwareaccelerators via industry-standard Layer 7 network protocolsand clientviewers. The new contributions of this work include a solution to theproblem of synchronizing X11 and OpenGL command streams, remote deliveryof parallel hardware-accelerated rendering, and a performance analysis ofseveral different optimizations that are generally applicable to avariety of rendering architectures. CRRSis fully operational, Open Sourcesoftware.

  6. Depth of Field Effects for Interactive Direct Volume Rendering

    KAUST Repository

    Schott, Mathias

    2011-06-01

    In this paper, a method for interactive direct volume rendering is proposed for computing depth of field effects, which previously were shown to aid observers in depth and size perception of synthetically generated images. The presented technique extends those benefits to volume rendering visualizations of 3D scalar fields from CT/MRI scanners or numerical simulations. It is based on incremental filtering and as such does not depend on any precomputation, thus allowing interactive explorations of volumetric data sets via on-the-fly editing of the shading model parameters or (multi-dimensional) transfer functions. © 2011 The Author(s).

  7. Morphological study of transpterional-insula approach using volume rendering.

    Science.gov (United States)

    Jia, Linpei; Su, Lue; Sun, Wei; Wang, Lina; Yao, Jihang; Li, Youqiong; Luo, Qi

    2012-11-01

    This study describes the measurements of inferior circular insular sulcus (ICIS) and the shortest distance from ICIS to the temporal horn and determines the position of the incision, which does less harm to the temporal stem in the transpterional-insula approach using volume-rendering technique. Results of the research showed that one-third point over the anterior side of ICIS may be the ideal penetration point during operation. And there is no difference between 2 hemispheres (P ICIS from other Chinese researches demonstrated that volume rendering is a reliable method in insular research that enables mass measurements.

  8. A Viewpoint on Medical Education in Iran

    Directory of Open Access Journals (Sweden)

    Mozafar Khazaei

    2013-08-01

    of students, determining appropriate strategies to prevent academic failure can preserve financial and human investment and enhance the academic rank of the universities. Taking the academic failure into account as one of the challenges facing medical education in Iran and doing intervention and meta-analysis studies are recommended.The increasing number of medical sciences students, especially general medicine during the recent years, that has caused congestion in theoretical and practical classes and relative decline in the quality of education, is also another noticeable challenge in the medical education. It seems necessary to have appropriate and prospective plan for this quantitative increase of students before they enter clinical wards in hospitals and to make anticipations for the preparation of physical and educational conditions and facilities needed for clinical and outpatient training. Taking into account of the ability and interest of the new generation of students in electronic facilities like internet and mobile and explicit emphasis of educational authorities and programmers of the country in the recent medical education congress (2013 on the necessity of applying virtual education, designing new educational programs and models based on virtual education can be considered as one of the methods of coping with the given challenge.

  9. Virtual reality

    Energy Technology Data Exchange (ETDEWEB)

    Pokras, V. [Liebherr Mining Equipment Co. (US)

    2005-03-01

    The paper weighs up the pros and cons between virtual prototyping and physical prototyping. Liebherr Mining Equipment Co. (LME) started evaluating the multi-body dynamic simulation of a full truck six years ago. LME has developed a series of dynamic models to optimise design of its T282B diesel-electric truck. Also, LME has developed a GPS-based technique called Virtual Mine Site that allows easy obtaining of a haul cycle 3D road profile for a specific mine site. The system can obtain not only a travel path and elevation profile but also body pitch, roll and acceleration components, allowing design optimisation and validation for structural and mechanical components. 2 figs., 2 photos.

  10. Viewpoint and pose in body-form adaptation.

    Science.gov (United States)

    Sekunova, Alla; Black, Michael; Parkinson, Laura; Barton, Jason J S

    2013-01-01

    Faces and bodies are complex structures, perception of which can play important roles in person identification and inference of emotional state. Face representations have been explored using behavioural adaptation: in particular, studies have shown that face aftereffects show relatively broad tuning for viewpoint, consistent with origin in a high-level structural descriptor far removed from the retinal image. Our goals were to determine first, if body aftereffects also showed a degree of viewpoint invariance, and second if they also showed pose invariance, given that changes in pose create even more dramatic changes in the 2-D retinal image. We used a 3-D model of the human body to generate headless body images, whose parameters could be varied to generate different body forms, viewpoints, and poses. In the first experiment, subjects adapted to varying viewpoints of either slim or heavy bodies in a neutral stance, followed by test stimuli that were all front-facing. In the second experiment, we used the same front-facing bodies in neutral stance as test stimuli, but compared adaptation from bodies in the same neutral stance to adaptation with the same bodies in different poses. We found that body aftereffects were obtained over substantial viewpoint changes, with no significant decline in aftereffect magnitude with increasing viewpoint difference between adapting and test images. Aftereffects also showed transfer across one change in pose but not across another. We conclude that body representations may have more viewpoint invariance than faces, and demonstrate at least some transfer across pose, consistent with a high-level structural description.

  11. Sensorial Virtualization: Coupling Gaming and Virtual Environment

    NARCIS (Netherlands)

    Garbaya, S.; Miraoui, C.; Wendrich, R.E.; Lim, T.; Stanescu, I.A.; Hauge, J.B.

    2014-01-01

    Virtual reality and virtualization are currently used to design complex systems and demonstrate that they represent the functionalities of real systems. However, the design refinement of the virtual environment (VE) and distributed virtual environment (DVE) are still time consuming and costly, as it

  12. Virtual teams

    OpenAIRE

    Sanders, David

    2010-01-01

    This paper describes some early results from observing and interviewing groups working to achieve intellectually complex tasks that required the use of computers, WWW and other research resources. Three groups were virtual (they were working at a distance and rarely meeting face to face) and two groups were simple control groups They were real groups (working in relatively close proximity so that face to face contact was possible most of the time). All five teams completed their tasks but a s...

  13. Virtual anthropology.

    Science.gov (United States)

    Weber, Gerhard W

    2015-02-01

    Comparative morphology, dealing with the diversity of form and shape, and functional morphology, the study of the relationship between the structure and the function of an organism's parts, are both important subdisciplines in biological research. Virtual anthropology (VA) contributes to comparative morphology by taking advantage of technological innovations, and it also offers new opportunities for functional analyses. It exploits digital technologies and pools experts from different domains such as anthropology, primatology, medicine, paleontology, mathematics, statistics, computer science, and engineering. VA as a technical term was coined in the late 1990s from the perspective of anthropologists with the intent of being mostly applied to biological questions concerning recent and fossil hominoids. More generally, however, there are advanced methods to study shape and size or to manipulate data digitally suitable for application to all kinds of primates, mammals, other vertebrates, and invertebrates or to issues regarding plants, tools, or other objects. In this sense, we could also call the field "virtual morphology." The approach yields permanently available virtual copies of specimens and data that comprehensively quantify geometry, including previously neglected anatomical regions. It applies advanced statistical methods, supports the reconstruction of specimens based on reproducible manipulations, and promotes the acquisition of larger samples by data sharing via electronic archives. Finally, it can help identify new, hidden traits, which is particularly important in paleoanthropology, where the scarcity of material demands extracting information from fragmentary remains. This contribution presents a current view of the six main work steps of VA: digitize, expose, compare, reconstruct, materialize, and share. The VA machinery has also been successfully used in biomechanical studies which simulate the stress and strains appearing in structures. Although

  14. Perception-based 3D tactile rendering from a single image for human skin examinations by dynamic touch.

    Science.gov (United States)

    Kim, K; Lee, S

    2015-05-01

    Diagnosis of skin conditions is dependent on the assessment of skin surface properties that are represented by more tactile properties such as stiffness, roughness, and friction than visual information. Due to this reason, adding tactile feedback to existing vision based diagnosis systems can help dermatologists diagnose skin diseases or disorders more accurately. The goal of our research was therefore to develop a tactile rendering system for skin examinations by dynamic touch. Our development consists of two stages: converting a single image to a 3D haptic surface and rendering the generated haptic surface in real-time. Converting to 3D surfaces from 2D single images was implemented with concerning human perception data collected by a psychophysical experiment that measured human visual and haptic sensibility to 3D skin surface changes. For the second stage, we utilized real skin biomechanical properties found by prior studies. Our tactile rendering system is a standalone system that can be used with any single cameras and haptic feedback devices. We evaluated the performance of our system by conducting an identification experiment with three different skin images with five subjects. The participants had to identify one of the three skin surfaces by using a haptic device (Falcon) only. No visual cue was provided for the experiment. The results indicate that our system provides sufficient performance to render discernable tactile rendering with different skin surfaces. Our system uses only a single skin image and automatically generates a 3D haptic surface based on human haptic perception. Realistic skin interactions can be provided in real-time for the purpose of skin diagnosis, simulations, or training. Our system can also be used for other applications like virtual reality and cosmetic applications. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Remote parallel rendering for high-resolution tiled display walls

    KAUST Repository

    Nachbaur, Daniel

    2014-11-01

    © 2014 IEEE. We present a complete, robust and simple to use hardware and software stack delivering remote parallel rendering of complex geometrical and volumetric models to high resolution tiled display walls in a production environment. We describe the setup and configuration, present preliminary benchmarks showing interactive framerates, and describe our contributions for a seamless integration of all the software components.

  16. Light Field Rendering for Head Mounted Displays using Pixel Reprojection

    DEFF Research Database (Denmark)

    Hansen, Anne Juhler; Kraus, Martin; Klein, Jákup

    2017-01-01

    of the information of the different images is redundant, we use pixel reprojection from the corner cameras to compute the remaining images in the light field. We compare the reprojected images with directly rendered images in a user test. In most cases, the users were unable to distinguish the images. In extreme...

  17. An experiment on the color rendering of different light sources

    Science.gov (United States)

    Fumagalli, Simonetta; Bonanomi, Cristian; Rizzi, Alessandro

    2013-02-01

    The color rendering index (CRI) of a light source attempts to measure how much the color appearance of objects is preserved when they are illuminated by the given light source. This problem is of great importance for various industrial and scientific fields, such as lighting architecture, design, ergonomics, etc. Usually a light source is specified through the Correlated Color Temperature or CCT. However two (or more) light sources with the same CCT but different spectral power distribution can exist. Therefore color samples viewed under two light sources with equal CCTs can appear different. Hence, the need for a method to assess the quality of a given illuminant in relation to color. Recently CRI has had a renewed interest because of the new LED-based lighting systems. They usually have a color rendering index rather low, but good preservation of color appearance and a pleasant visual appearance (visual appeal). Various attempts to develop a new color rendering index have been done so far, but still research is working for a better one. This article describes an experiment performed by human observers concerning the appearance preservation of color under some light sources, comparing it with a range of available color rendering indices.

  18. Interacting with Stroke-Based Rendering on a Wall Display

    NARCIS (Netherlands)

    Grubert, Jens; Hanckock, Mark; Carpendale, Sheelagh; Tse, Edward; Isenberg, Tobias

    2007-01-01

    We introduce two new interaction techniques for creating and interacting with non-photorealistic images using stroke-based rendering. We provide bimanual control of a large interactive canvas through both remote pointing and direct touch. Remote pointing allows people to sit and interact at a distan

  19. Selection of plasters and renders for salt laden masonry substrates

    NARCIS (Netherlands)

    Groot, C.; Hees, R.P.J. van; Wijffels, T.J.

    2009-01-01

    The choice of a repair plaster or render by architects often appears to be the result of fortuitous circumstances, such as prior experience with a plaster or a recommendation by a producer. Seldom is the choice based on a sound assessment of the state of the building and the wall that is to be repai

  20. Depth-Dependent Halos : Illustrative Rendering of Dense Line Data

    NARCIS (Netherlands)

    Everts, Maarten H.; Bekker, Henk; Roerdink, Jos B.T.M.; Isenberg, Tobias

    2009-01-01

    We present a technique for the illustrative rendering of 3D line data at interactive frame rates. We create depth-dependent halos around lines to emphasize tight line bundles while less structured lines are de-emphasized. Moreover, the depth-dependent halos combined with depth cueing via line width

  1. Interacting with Stroke-Based Rendering on a Wall Display

    NARCIS (Netherlands)

    Grubert, Jens; Hanckock, Mark; Carpendale, Sheelagh; Tse, Edward; Isenberg, Tobias

    2007-01-01

    We introduce two new interaction techniques for creating and interacting with non-photorealistic images using stroke-based rendering. We provide bimanual control of a large interactive canvas through both remote pointing and direct touch. Remote pointing allows people to sit and interact at a

  2. 7 CFR 54.1016 - Advance information concerning service rendered.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Advance information concerning service rendered. 54..., Processing, and Packaging of Livestock and Poultry Products § 54.1016 Advance information concerning service... MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE...

  3. 7 CFR 53.17 - Advance information concerning service rendered.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Advance information concerning service rendered. 53.17... (CONTINUED) LIVESTOCK (GRADING, CERTIFICATION, AND STANDARDS) Regulations Service § 53.17 Advance information... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED)...

  4. The Viewpoint Paradigm: a semiotic based approach for the intelligibility of a cooperative designing process

    Directory of Open Access Journals (Sweden)

    Pierre-Jean Charrel

    2002-11-01

    Full Text Available The concept of viewpoint is studied in the field of the modelling and the knowledge management concerned in the upstream phases of a designing process. The concept is approached by semiotics, i.e. in dealing with the requirements so that an actor gives sense to an object. This gives means to transform the intuitive concepts of viewpoint and relation between viewpoints into the Viewpoint Paradigm: the sense of an object is the integration of the viewpoints which exert on it. The elements of this paradigm are integrated in a general model, which defines two concepts formally: Viewpoint and Correlation of viewpoints. The Viewpoint Paradigm is then implemented in operational concerns which are related with the intelligibility of the designing process. Two models of viewpoint and correlation are proposed. They raise of viewpoints management such as one can identify them in the written documents of a project.

  5. Data Content Protection for Virtual Libraries Heritage

    Directory of Open Access Journals (Sweden)

    Mihai DOINEA

    2016-01-01

    Full Text Available This paper presents aspects of digital content protection in virtual library systems. The legislation aspects are presented to better emphasize the need of new security mechanisms. Integrated library systems architecture is presented with focus on their main purpose, manipulating and rendering digital content to end-users. The cultural heritage stored in such systems is an important asset that needs to be protected against malicious manipulation. The characteristics of a smart virtual library, supported by an integrated library system, are analyzed and a security model is proposed for implementation, based on its particularities. The model aims to be an interface between the interactions of anonymous users with the Online Public Access Catalog of a virtual library that assures the protection of digital content. Conclusions are drawn to better support the idea of cultural persistence by the use of Information Systems.

  6. Visualizing vascular structures in virtual environments

    Science.gov (United States)

    Wischgoll, Thomas

    2013-01-01

    In order to learn more about the cause of coronary heart diseases and develop diagnostic tools, the extraction and visualization of vascular structures from volumetric scans for further analysis is an important step. By determining a geometric representation of the vasculature, the geometry can be inspected and additional quantitative data calculated and incorporated into the visualization of the vasculature. To provide a more user-friendly visualization tool, virtual environment paradigms can be utilized. This paper describes techniques for interactive rendering of large-scale vascular structures within virtual environments. This can be applied to almost any virtual environment configuration, such as CAVE-type displays. Specifically, the tools presented in this paper were tested on a Barco I-Space and a large 62x108 inch passive projection screen with a Kinect sensor for user tracking.

  7. A solution for actors' viewpoints representation with collaborative product development

    CERN Document Server

    Geryville, Hichem; Ouzrout, Yacine; Sapidis, Nikolaos

    2007-01-01

    As product complexity and marketing competition increase, a collaborative product development is necessary for companies which develop high quality products in short lead-times. To support product actors from different fields, disciplines, and locations, wishing to exchange and share information, the representation of the actors' viewpoints is the underlying requirement of the collaborative product development. The actors' viewpoints approach was designed to provide an organisational framework following the actors' perspectives in the collaboration, and their relationships, could be explicitly gathered and formatted. The approach acknowledges the inevitability of multiple integration of product information as different views, promotes gathering of actors' interests, and encourages retrieved adequate information while providing support for integration through PLM and/or SCM collaboration. In this paper, a solution for neutral viewpoints representation is proposed. The product, process, and organisation informa...

  8. Repetition blindness for natural images of objects with viewpoint changes

    Directory of Open Access Journals (Sweden)

    Stephane eBuffat

    2013-01-01

    Full Text Available When stimuli are repeated in a rapid serial visual presentation (RSVP, observers sometimes fail to report the second occurrence of a target. This phenomenon is referred to as repetition blindness (RB. We report an RSVP experiment with photographs in which we manipulated object viewpoints between the first and second occurrences of a target (0-, 45-, or 90-degree changes, and spatial frequency content. Natural images were spatially filtered to produce low, medium, or high spatial-frequency stimuli. RB was observed for all filtering conditions. Surprisingly, for full-spectrum images, RB increased significantly as the viewpoint reached 90 degrees. For filtered images, a similar pattern of results was found for all conditions except for medium spatial-frequency stimuli. These findings suggest that object recognition in RSVP are subtended by viewpoint-specific representations for all spatial frequencies except medium ones.

  9. Virtual Reality

    Directory of Open Access Journals (Sweden)

    Bhavana Gupta

    2012-10-01

    Full Text Available An artificial environment created with co mputer hardware and software and presented to the user in such a way that it appears and feels like a real environment. To "enter" a virtual reality, a user does special gloves, earphones, and goggles, all of which receive their input from the computer system. In this way, at least three of the five senses are controlled by the computer. In addition to feeding sensory input to the user, the devices also monitor the user's actions

  10. A Virtual Standoff – Using Q Methodology to Analyze Virtual Reference

    Directory of Open Access Journals (Sweden)

    Susan Hurst

    2007-12-01

    Full Text Available Objective ‐ To develop an exploratory understanding of reference librarians’ perceptions of virtual reference.Methods ‐ Q methodology was used to uncover points of view about virtual reference. Thirty‐four librarians sorted 28 statements covering a wide range of opinions about virtual reference. Factor analysis was used to analyze the Q‐sorts and factor scores were calculated to aid the task of understanding and interpretation.Results ‐ The factor analysis revealed three attitudinal typologies: Technophiles, Traditionalists, and Pragmatists. Each factor represents a group of reference librarians who think similarly about virtual reference. Conclusion ‐ This type of analysis provides data on the actual range of feelings and attitudes about providing virtual reference services. The factor analysis demonstrates that there are still a variety of strongly held viewpoints concerning virtual reference. Convergence towards either acceptance or rejection does not appear to be forthcoming. By using this type of analysis and the resulting data as a basis for decision making, administrators could staff services more efficiently and with the resulting better fit between librarians and their positions, possibly increase morale.

  11. Mathematical Processes: A Viewpoint-oriented Manipulation Perspective

    DEFF Research Database (Denmark)

    Badie, Farshad

    2008-01-01

    View-point oriented manipulation of concepts can be helpful for generating new ideas in basic sciences and in the meantime, justifying the processes that are principally meaningful to the related disciplines. Mathematics, as a major ground for basic sciences, seems to be an appropriate exemplar...... consistent. In this paper, having reviewed the principles of view-point oriented manipulation, mathematical processes will then be discussed in this regard and an example will be presented showing the way it works for transforming a formalism into a new one....

  12. An unconventional depiction of viewpoint in rock art.

    Science.gov (United States)

    Pettigrew, Jack; Scott-Virtue, Lee

    2015-01-01

    Rock art in Africa sometimes takes advantage of three-dimensional features of the rock wall, such as fissures or protuberances, that can be incorporated into the artistic composition (Lewis-Williams, 2002). More commonly, rock artists choose uniform walls on which two-dimensional depictions may represent three-dimensional figures or objects. In this report we present such a two-dimensional depiction in rock art that we think reveals an intention by the artist to represent an unusual three-dimensional viewpoint, namely, with the two human figures facing into the rock wall, instead of the accustomed Western viewpoint facing out!

  13. Modeling and Optimization of a Tree Based on Virtual Reality for Immersive Virtual Landscape Generation

    Directory of Open Access Journals (Sweden)

    Jinmo Kim

    2016-09-01

    Full Text Available This study proposes a modeling method that can effectively generate multiple diverse digital trees for creating immersive virtual landscape based on virtual reality and an optimization method for real-time rendering. The proposed method simplifies a process of procedures from growth of tree models to the generation of the three-dimensional branch geometric model. Here, the procedural branch graph (PBG algorithm is proposed, which simultaneously and effectively generates diverse trees that have a similar branch pattern. Moreover, the optimization method is designed in a polygon-based branch model which controls the resolution of tree models according to the distance from the camera to generate a tree model structure that is appropriate for an immersive system based on virtual reality. Finally, a virtual reality system is established based on the Oculus SDK (Software Development Kit and Unity3D engine. In this process, the image processing-based pixel to tree (PTT method is proposed as a technique for easily and efficiently generating a virtual landscape by allocating multiple trees on terrain. An immersive virtual landscape that has a stereoscopic perception and spatial impression is created through the proposed method and whether it can deliver experience of nature in virtual reality to the users was checked through an experiment.

  14. 9 CFR 315.1 - Carcasses and parts passed for cooking; rendering into lard or tallow.

    Science.gov (United States)

    2010-01-01

    ...; rendering into lard or tallow. 315.1 Section 315.1 Animals and Animal Products FOOD SAFETY AND INSPECTION... PARTS PASSED FOR COOKING § 315.1 Carcasses and parts passed for cooking; rendering into lard or tallow... subchapter or rendered into tallow, provided such rendering is done in the following manner: (a) When...

  15. Virtual screening of virtual libraries.

    Science.gov (United States)

    Green, Darren V S

    2003-01-01

    Virtual screening of virtual libraries (VSVL) is a rapidly changing area of research. Great efforts are being made to produce better algorithms, selection methods and infrastructure. Yet, the number of successful examples in the literature is not impressive, although the quality of work certainly is high. Why is this? One reason is that these methods tend to be applied at the lead generation stage and therefore there is a large lead-time before successful examples appear in the literature. However, any computational chemist would confirm that these methods are successful and there exists a glut of start-up companies specialising in virtual screening. Moreover, the scientific community would not be focussing so much attention on this area if it were not yielding results. Even so, the paucity of literature data is certainly a hindrance to the development of better methods. The VSVL process is unique within the discovery process, in that it is the only method that can screen the > 10(30) genuinely novel molecules out there. Already, some VSVL methods are evaluating 10(13) compounds, a capacity that high throughput screening can only dream of. There is a huge potential advantage for the company that develops efficient and effective methods, for lead generation, lead hopping and optimization of both potency and ADME properties. To do this, it requires more than the software, it requires confidence to exploit the methodology, to commit synthesis on the basis of it, and to build this approach into the medicinal chemistry strategy. It is a fact that these tools remain quite daunting for the majority of scientists working at the bench. The routine use of these methods is not simply a matter of education and training. Integration of these methods into accessible and robust end user software, without dilution of the science, must be a priority. We have reached a coincidence, where several technologies have the required level of maturity predictive computational chemistry

  16. Hybrid fur rendering: combining volumetric fur with explicit hair strands

    DEFF Research Database (Denmark)

    Andersen, Tobias Grønbeck; Falster, Viggo; Frisvad, Jeppe Revall

    2016-01-01

    Hair is typically modeled and rendered using either explicitly defined hair strand geometry or a volume texture of hair densities. Taken each on their own, these two hair representations have difficulties in the case of animal fur as it consists of very dense and thin undercoat hairs in combination...... with coarse guard hairs. Explicit hair strand geometry is not well-suited for the undercoat hairs, while volume textures are not well-suited for the guard hairs. To efficiently model and render both guard hairs and undercoat hairs, we present a hybrid technique that combines rasterization of explicitly...... defined guard hairs with ray marching of a prismatic shell volume with dynamic resolution. The latter is the key to practical combination of the two techniques, and it also enables a high degree of detail in the undercoat. We demonstrate that our hybrid technique creates a more detailed and soft fur...

  17. Chromium Renderserver: scalable and open remote rendering infrastructure.

    Science.gov (United States)

    Paul, Brian; Ahern, Sean; Bethel, E Wes; Brugger, Eric; Cook, Rich; Daniel, Jamison; Lewis, Ken; Owen, Jens; Southard, Dale

    2008-01-01

    Chromium Renderserver (CRRS) is software infrastructure that provides the ability for one or more users to run and view image output from unmodified, interactive OpenGL and X11 applications on a remote, parallel computational platform equipped with graphics hardware accelerators via industry-standard Layer 7 network protocols and client viewers. The new contributions of this work include a solution to the problem of synchronizing X11 and OpenGL command streams, remote delivery of parallel hardware accelerated rendering, and a performance analysis of several different optimizations that are generally applicable to a variety of rendering architectures. CRRS is fully operational, Open Source software. imagery and sending it to a remote viewer.

  18. Hybrid fur rendering: combining volumetric fur with explicit hair strands

    DEFF Research Database (Denmark)

    Andersen, Tobias Grønbeck; Falster, Viggo; Frisvad, Jeppe Revall

    2016-01-01

    Hair is typically modeled and rendered using either explicitly defined hair strand geometry or a volume texture of hair densities. Taken each on their own, these two hair representations have difficulties in the case of animal fur as it consists of very dense and thin undercoat hairs in combination...... with coarse guard hairs. Explicit hair strand geometry is not well-suited for the undercoat hairs, while volume textures are not well-suited for the guard hairs. To efficiently model and render both guard hairs and undercoat hairs, we present a hybrid technique that combines rasterization of explicitly...... defined guard hairs with ray marching of a prismatic shell volume with dynamic resolution. The latter is the key to practical combination of the two techniques, and it also enables a high degree of detail in the undercoat. We demonstrate that our hybrid technique creates a more detailed and soft fur...

  19. Trust and virtual worlds

    DEFF Research Database (Denmark)

    Ess, Charles; Thorseth, May

    2011-01-01

    We collect diverse philosophical analyses of the issues and problems clustering around trust online with specific attention to establishing trust in virtual environments. The book moves forward important discussions of how virtual worlds and virtuality are to be defined and understood; the role o...... by virtuality, such as virtual child pornography. The introduction further develops a philosophical anthropology, rooted in Kantian ethics, phenomenology, virtue ethics, and feminist perspectives, that grounds a specific approach to ethical issues in virtual environments....

  20. Rendering Optical Effects Based on Spectra Representation in Complex Scenes

    OpenAIRE

    Dong, Weiming

    2006-01-01

    http://www.springerlink.com/; Rendering the structural color of natural objects or modern industrial products in the 3D environment is not possible with RGB-based graphics platforms and software and very time consuming, even with the most efficient spectra representation based methods previously proposed. Our framework allows computing full spectra light object interactions only when it is needed, i.e. for the part of the scene that requires simulating special spectra sensitive phenomena. Ach...

  1. Anisotropic 3D texture synthesis with application to volume rendering

    DEFF Research Database (Denmark)

    Laursen, Lasse Farnung; Ersbøll, Bjarne Kjær; Bærentzen, Jakob Andreas

    2011-01-01

    We present a novel approach to improving volume rendering by using synthesized textures in combination with a custom transfer function. First, we use existing knowledge to synthesize anisotropic solid textures to fit our volumetric data. As input to the synthesis method, we acquire high quality....... This method is applied to a high quality visualization of a pig carcass, where samples of meat, bone, and fat have been used to produce the anisotropic 3D textures....

  2. Empirical evaluation of mapping functions for navigation in virtual reality using phones with integrated sensors

    KAUST Repository

    Benzina, Amal

    2012-01-01

    Mobile phones provide an interesting all-in-one alternative for 3D input devices in virtual environments. Mobile phones are becoming touch sensitive and spatially aware, and they are now part of our daily activities. We present Phone-Based Motion Control, a novel one-handed travel technique for a virtual environment. The technique benefits from the touch capability offered by growing number of mobile phones to change viewpoint translation in virtual environments, while the orientation of the viewpoint is controlled by built-in sensors in the mobile phone. The travel interaction separates translation (touch based translation control) and rotation (steer based rotation control), putting each set of degrees of freedom (DOF) to a separate interaction technique (separability). This paper examines, how many DOF are needed to perform the travel task as easy and comfortable as possible. It also investigates different mapping functions between the user\\'s actions on the mobile phone and the viewpoint change in the virtual environment. Therefore, four techniques are implemented: rotate by heading, rotate by roll, rotate by roll with fixed horizon and a merged rotation. Each technique has either 4 or 5 DOF and different mappings between phone and viewpoint coordinates in the virtual environment. We perform an extensive user study to explore different aspects related to the travel techniques in terms of DOF and mapping functions. Results of the user evaluation show that 4 DOF techniques seem to perform better the travel task. Even though, the results were not statistically decisive in favor of the usage of the mobile roll to control the viewpoint heading in the virtual environment despite the good results, there is a clear tendency from the users to prefer the mobile roll as the desired mapping. Copyright 2012 ACM.

  3. Real-time rendering of optical effects using spatial convolution

    Science.gov (United States)

    Rokita, Przemyslaw

    1998-03-01

    Simulation of special effects such as: defocus effect, depth-of-field effect, raindrops or water film falling on the windshield, may be very useful in visual simulators and in all computer graphics applications that need realistic images of outdoor scenery. Those effects are especially important in rendering poor visibility conditions in flight and driving simulators, but can also be applied, for example, in composing computer graphics and video sequences- -i.e. in Augmented Reality systems. This paper proposes a new approach to the rendering of those optical effects by iterative adaptive filtering using spatial convolution. The advantage of this solution is that the adaptive convolution can be done in real-time by existing hardware. Optical effects mentioned above can be introduced into the image computed using conventional camera model by applying to the intensity of each pixel the convolution filter having an appropriate point spread function. The algorithms described in this paper can be easily implemented int the visualization pipeline--the final effect may be obtained by iterative filtering using a single hardware convolution filter or with the pipeline composed of identical 3 X 3 filters placed as the stages of this pipeline. Another advantage of the proposed solution is that the extension based on proposed algorithm can be added to the existing rendering systems as a final stage of the visualization pipeline.

  4. High Performance GPU-Based Fourier Volume Rendering.

    Science.gov (United States)

    Abdellah, Marwan; Eldeib, Ayman; Sharawi, Amr

    2015-01-01

    Fourier volume rendering (FVR) is a significant visualization technique that has been used widely in digital radiography. As a result of its (N (2)log⁡N) time complexity, it provides a faster alternative to spatial domain volume rendering algorithms that are (N (3)) computationally complex. Relying on the Fourier projection-slice theorem, this technique operates on the spectral representation of a 3D volume instead of processing its spatial representation to generate attenuation-only projections that look like X-ray radiographs. Due to the rapid evolution of its underlying architecture, the graphics processing unit (GPU) became an attractive competent platform that can deliver giant computational raw power compared to the central processing unit (CPU) on a per-dollar-basis. The introduction of the compute unified device architecture (CUDA) technology enables embarrassingly-parallel algorithms to run efficiently on CUDA-capable GPU architectures. In this work, a high performance GPU-accelerated implementation of the FVR pipeline on CUDA-enabled GPUs is presented. This proposed implementation can achieve a speed-up of 117x compared to a single-threaded hybrid implementation that uses the CPU and GPU together by taking advantage of executing the rendering pipeline entirely on recent GPU architectures.

  5. High Performance GPU-Based Fourier Volume Rendering

    Directory of Open Access Journals (Sweden)

    Marwan Abdellah

    2015-01-01

    Full Text Available Fourier volume rendering (FVR is a significant visualization technique that has been used widely in digital radiography. As a result of its O(N2log⁡N time complexity, it provides a faster alternative to spatial domain volume rendering algorithms that are O(N3 computationally complex. Relying on the Fourier projection-slice theorem, this technique operates on the spectral representation of a 3D volume instead of processing its spatial representation to generate attenuation-only projections that look like X-ray radiographs. Due to the rapid evolution of its underlying architecture, the graphics processing unit (GPU became an attractive competent platform that can deliver giant computational raw power compared to the central processing unit (CPU on a per-dollar-basis. The introduction of the compute unified device architecture (CUDA technology enables embarrassingly-parallel algorithms to run efficiently on CUDA-capable GPU architectures. In this work, a high performance GPU-accelerated implementation of the FVR pipeline on CUDA-enabled GPUs is presented. This proposed implementation can achieve a speed-up of 117x compared to a single-threaded hybrid implementation that uses the CPU and GPU together by taking advantage of executing the rendering pipeline entirely on recent GPU architectures.

  6. Viewpoint: Transatlantic Scholarship on Victorian Literature and Culture

    OpenAIRE

    Isobel Armstrong

    2009-01-01

    This viewpoint offers a comparison of recent British and American criticism of Victorian literature and culture, encompassing Dickens, Tennyson, the epic and ethical criticism. Discussion centres on recent studies by Sally Ledger, Rosemarie Bodenheimer, Cornelia Pearsall, Kirstie Blair, Simon Dentith, Herbert Tucker, Andrew Miller and Mike Sanders.

  7. Viewpoint: Transatlantic Scholarship on Victorian Literature and Culture

    Directory of Open Access Journals (Sweden)

    Isobel Armstrong

    2009-11-01

    Full Text Available This viewpoint offers a comparison of recent British and American criticism of Victorian literature and culture, encompassing Dickens, Tennyson, the epic and ethical criticism. Discussion centres on recent studies by Sally Ledger, Rosemarie Bodenheimer, Cornelia Pearsall, Kirstie Blair, Simon Dentith, Herbert Tucker, Andrew Miller and Mike Sanders.

  8. General Education Teachers' Viewpoints Concerning Response to Intervention

    Science.gov (United States)

    Ryan, Eileen Maloney

    2011-01-01

    This descriptive case study explored the viewpoints of general education teachers implementing Response to Intervention (RTI). The research question addressed the knowledge and perceptions of the classroom teachers concerning RTI. Participants, 14 second and third grade teachers, participated in interviews near the end of their third year of…

  9. Does Zika Virus Cause Microcephaly - Applying the Bradford Hill Viewpoints

    Science.gov (United States)

    Awadh, Asma; Chughtai, Abrar Ahmad; Dyda, Amalie; Sheikh, Mohamud; Heslop, David J.; MacIntyre, Chandini Raina

    2017-01-01

    Introduction: Zika virus has been documented since 1952, but been associated with mild, self-limiting disease. Zika virus is classified as an arbovirus from a family of Flaviviridae and primarily spread by Aedes Aegypti mosquitos. However, in a large outbreak in Brazil in 2015, Zika virus has been associated with microcephaly. Methods: In this review we applied the Bradford-Hill viewpoints  to investigate the association between Zika virus and microcephaly. We examined historical studies, available data and also compared historical rates of microcephaly prior to the Zika virus outbreak. The available evidence was reviewed against the Bradford Hill viewpoints. Results: All  the nine criteria were met to varying degrees: strength of association, consistency of the association, specificity, temporality, plausibility, coherence, experimental evidence, biological gradient and analogy. Conclusion: Using the Bradford Hill Viewpoints as an evaluation framework for causation is highly suggestive that the association between Zika virus and microcephaly is causal. Further studies using animal models on the viewpoints which were not as strongly fulfilled would be helpful. PMID:28357156

  10. Humanism Factors and Islam Viewpoint from Motahri's Point of View

    Science.gov (United States)

    Yousefi, Zargham; Yousefy, Alireza; Keshtiaray, Narges

    2015-01-01

    The aim of this research is to criticize liberal humanism based on Islam viewpoint emphasizing Motahri's point of view. In this paper, the researchers tried to identify liberalism humanism factors with analytical look in order to present a new categorization called "main factor of liberal humanism". Then, each factor was studied and…

  11. Humanism Factors and Islam Viewpoint from Motahri's Point of View

    Science.gov (United States)

    Yousefi, Zargham; Yousefy, Alireza; Keshtiaray, Narges

    2015-01-01

    The aim of this research is to criticize liberal humanism based on Islam viewpoint emphasizing Motahri's point of view. In this paper, the researchers tried to identify liberalism humanism factors with analytical look in order to present a new categorization called "main factor of liberal humanism". Then, each factor was studied and…

  12. Towards a Normalised 3D Geovisualisation: The Viewpoint Management

    Science.gov (United States)

    Neuville, R.; Poux, F.; Hallot, P.; Billen, R.

    2016-10-01

    This paper deals with the viewpoint management in 3D environments considering an allocentric environment. The recent advances in computer sciences and the growing number of affordable remote sensors lead to impressive improvements in the 3D visualisation. Despite some research relating to the analysis of visual variables used in 3D environments, we notice that it lacks a real standardisation of 3D representation rules. In this paper we study the "viewpoint" as being the first considered parameter for a normalised visualisation of 3D data. Unlike in a 2D environment, the viewing direction is not only fixed in a top down direction in 3D. A non-optimal camera location means a poor 3D representation in terms of relayed information. Based on this statement we propose a model based on the analysis of the computational display pixels that determines a viewpoint maximising the relayed information according to one kind of query. We developed an OpenGL prototype working on screen pixels that allows to determine the optimal camera location based on a screen pixels colour algorithm. The viewpoint management constitutes a first step towards a normalised 3D geovisualisation.

  13. An approach to relate viewpoints and modeling languages

    NARCIS (Netherlands)

    Dijkman, R.M.; Quartel, Dick; Ferreira Pires, Luis; van Sinderen, Marten J.; Duddy, K.

    The architectural design of distributed enterprise applications from the viewpoints of different stakeholders has been proposed for some time, for example, as part of RM-ODP and IEEE 1471, and seems now-a-days to gain acceptance in practice. However, much work remains to be done on the relationships

  14. Didactic Competencies of Teachers from the Learner's Viewpoint

    Science.gov (United States)

    Zuljan, Milena Valencic; Peklaj, Cirila; Pecjak, Sonja; Puklek, Melita; Kalin, Jana

    2012-01-01

    Teacher competencies can be researched in many different ways. In the present article they are studied from the learner's viewpoint. The article presents results of the extensive project "Teacher Education for New Competencies for the Knowledge Society and the Role of these Competencies in Educational Goal Attainment at School", carried…

  15. Partition of biocides between water and inorganic phases of renders with organic binder

    DEFF Research Database (Denmark)

    Urbanczyk, Michal M; Bollmann, Ulla E; Bester, Kai

    2016-01-01

    , the partition of biocides between water and inorganic phases of render with organic binder was investigated. The partition constants of carbendazim, diuron, iodocarb, isoproturon, cybutryn (irgarol), octylisothiazolinone, terbutryn, and tebuconazole towards minerals typically used in renders, e.g. barite...... with render-water distribution constants of two artificially made renders showed that the distribution constants can be estimated based on partition constants of compounds for individual components of the render....

  16. Realidad virtual y materialidad

    OpenAIRE

    Pérez Herranz, Fernando Miguel

    2009-01-01

    1. Fenomenología de partida: Real / Simbólico / Imaginario 2. Realidad 3. Virtual 3.1. Virtual / real / posible / probable 3.2. Los contextos de la realidad virtual A) REALIDAD VIRTUAL INMERSIVA B) REALIDAD VIRTUAL NO INMERSIVA C) REALIDAD VIRTUAL Y DIGITALIZACIÓN 3.3. Cruce virtual / real 3.4. Cuestiones filosóficas 4. Materialidad 5. Materialidad y descentramiento 5.1. Ejemplos de descentramiento en los contextos de Realidad Virtual A’) DUALISMO CARTESIANO, CUERPO Y «CIBORG » B’) EL ESPÍRIT...

  17. Virtual Touch

    DEFF Research Database (Denmark)

    Stenslie, Ståle

    The central focus of this thesis is the use and experience of touch in artistic, multimodal and computer-based environments. The haptic experience of touch is an area that has only received limited research-based interest. Touch is too often seen as the effect, and not the cause of our everyday...... Erotogod. The third chapter investigates the foundations of touch through a physiological and psychological approach. Chapter four presents an alternative haptic history of Virtual Realities through the presentation and discussion of several technological and artistic works that are computer......-based. In chapter five touch is approached from a theoretical point of view. It develops a theory of touch based on phenomenology and shows how this approach advances an embodied thinking. Chapter six presents practice-based experiments of touch through the Erotogod installation. The last and seventh part...

  18. Virtual materiality

    DEFF Research Database (Denmark)

    Søndergaard, Dorte Marie

    to bullying practices in school. The theoretical question concerns the conceptual challenges that arise from empirical data which contain 1. children’s narratives about matter and meaning as they intertwine in their nightly dreams, 2. the observations of children’s’ computer gaming practices as well...... the character and effects of the skeleton army, which came across the sea to drown the boys in Phillip’s school class: a central scene in one of the dreams he recounted? Are the boat and the water in that dream materialities? Discourse? Part of some kind of enacted subjectivity? How will our decision of which......, experiences etc. Among these many interacting forces technologies play a crucial part – as do bodies, whether they are fighting, playing, dreaming, loving or hating bodies. And as do weapons - whether in the shape of virtual weapons of the computer games (as in e.g. Battlefield, Counter Strike, Grand Theft...

  19. Virtual Laboratories

    CERN Document Server

    Hut, P

    2006-01-01

    At the frontier of most areas in science, computer simulations play a central role. The traditional division of natural science into experimental and theoretical investigations is now completely outdated. Instead, theory, simulation, and experimentation form three equally essential aspects, each with its own unique flavor and challenges. Yet, education in computational science is still lagging far behind, and the number of text books in this area is minuscule compared to the many text books on theoretical and experimental science. As a result, many researchers still carry out simulations in a haphazard way, without properly setting up the computational equivalent of a well equipped laboratory. The art of creating such a virtual laboratory, while providing proper extensibility and documentation, is still in its infancy. A new approach is described here, Open Knowledge, as an extension of the notion of Open Source software. Besides open source code, manuals, and primers, an open knowledge project provides simul...

  20. Culture-bound syndrome and a culturally sensitive approach: from a viewpoint of medical anthropology.

    Science.gov (United States)

    Shimoji, A; Miyakawa, T

    2000-08-01

    Some aspects of the culture-bound syndrome are presented for discussion. From the psychiatric and medical anthropological viewpoints, kamidaari is described as an initiatory illness for seeing a shaman, and focus on clinical realities developing between different therapeutic subcultures in the same culture and the complementary practices of two epistemological ones, namely, the shamanistic and modern psychiatric system in the shamanistic climate. It is suggested that the culture-bound syndrome that reflects cultural influences on disease patterns and renders them difficult to place in a universal classificatory system should be seen as a vernacular bricolage or as tactics used by people within the web of their own local culture of origin. Therapists who treat patients in a cross-epistemological milieu should be aware of the subcultural-epistemological issues that may affect the clinical process. It should be recognized that, depending on the nature of a particular psychiatric crisis, the clinical encounter is straddling the boundaries of multiple clinical realities. At every stage in the clinical field, there is an intersection, consonance, or interruption of rejoinders in the open dialog by all those engaged in the clinical time. Aspects of climatic, culturally sensitive psychotherapy will be described, and the concept of the culture-bound syndrome will be reconsidered. Our approach could be seen as 'situation- and fudo-bound'.

  1. Post-processing methods of rendering and visualizing 3-D reconstructed tomographic images

    Energy Technology Data Exchange (ETDEWEB)

    Wong, S.T.C. [Univ. of California, San Francisco, CA (United States)

    1997-02-01

    The purpose of this presentation is to discuss the computer processing techniques of tomographic images, after they have been generated by imaging scanners, for volume visualization. Volume visualization is concerned with the representation, manipulation, and rendering of volumetric data. Since the first digital images were produced from computed tomography (CT) scanners in the mid 1970s, applications of visualization in medicine have expanded dramatically. Today, three-dimensional (3D) medical visualization has expanded from using CT data, the first inherently digital source of 3D medical data, to using data from various medical imaging modalities, including magnetic resonance scanners, positron emission scanners, digital ultrasound, electronic and confocal microscopy, and other medical imaging modalities. We have advanced from rendering anatomy to aid diagnosis and visualize complex anatomic structures to planning and assisting surgery and radiation treatment. New, more accurate and cost-effective procedures for clinical services and biomedical research have become possible by integrating computer graphics technology with medical images. This trend is particularly noticeable in current market-driven health care environment. For example, interventional imaging, image-guided surgery, and stereotactic and visualization techniques are now stemming into surgical practice. In this presentation, we discuss only computer-display-based approaches of volumetric medical visualization. That is, we assume that the display device available is two-dimensional (2D) in nature and all analysis of multidimensional image data is to be carried out via the 2D screen of the device. There are technologies such as holography and virtual reality that do provide a {open_quotes}true 3D screen{close_quotes}. To confine the scope, this presentation will not discuss such approaches.

  2. Hand-tool-tissue interaction forces in neurosurgery for haptic rendering.

    Science.gov (United States)

    Aggravi, Marco; De Momi, Elena; DiMeco, Francesco; Cardinale, Francesco; Casaceli, Giuseppe; Riva, Marco; Ferrigno, Giancarlo; Prattichizzo, Domenico

    2016-08-01

    Haptics provides sensory stimuli that represent the interaction with a virtual or tele-manipulated object, and it is considered a valuable navigation and manipulation tool during tele-operated surgical procedures. Haptic feedback can be provided to the user via cutaneous information and kinesthetic feedback. Sensory subtraction removes the kinesthetic component of the haptic feedback, having only the cutaneous component provided to the user. Such a technique guarantees a stable haptic feedback loop, while it keeps the transparency of the tele-operation system high, which means that the system faithfully replicates and render back the user's directives. This work focuses on checking whether the interaction forces during a bench model neurosurgery operation can lie in the solely cutaneous perception of the human finger pads. If this assumption is found true, it would be possible to exploit sensory subtraction techniques for providing surgeons with feedback from neurosurgery. We measured the forces exerted to surgical tools by three neurosurgeons performing typical actions on a brain phantom, using contact force sensors, while the forces exerted by the tools to the phantom tissue were recorded using a load cell placed under the brain phantom box. The measured surgeon-tool contact forces were 0.01-3.49 N for the thumb and 0.01-6.6 N for index and middle finger, whereas the measured tool-tissue interaction forces were from six to 11 times smaller than the contact forces, i.e., 0.01-0.59 N. The measurements for the contact forces fit the range of the cutaneous sensitivity for the human finger pad; thus, we can say that, in a tele-operated robotic neurosurgery scenario, it would possible to render forces at the fingertip level by conveying haptic cues solely through the cutaneous channel of the surgeon's finger pads. This approach would allow high transparency and high stability of the haptic feedback loop in a tele-operation system.

  3. Microsoft Virtualization Master Microsoft Server, Desktop, Application, and Presentation Virtualization

    CERN Document Server

    Olzak, Thomas; Boomer, Jason; Keefer, Robert M

    2010-01-01

    Microsoft Virtualization helps you understand and implement the latest virtualization strategies available with Microsoft products. This book focuses on: Server Virtualization, Desktop Virtualization, Application Virtualization, and Presentation Virtualization. Whether you are managing Hyper-V, implementing desktop virtualization, or even migrating virtual machines, this book is packed with coverage on all aspects of these processes. Written by a talented team of Microsoft MVPs, Microsoft Virtualization is the leading resource for a full installation, migration, or integration of virtual syste

  4. Cloud-based Virtual Organization Engineering

    Directory of Open Access Journals (Sweden)

    Liviu Gabriel CRETU

    2012-01-01

    Full Text Available Nowadays we may notice that SOA arrived to its maturity stage and Cloud Computing brings the next paradigm-shift regarding the software delivery business model. In such a context, we consider that there is a need for frameworks to guide the creation, execution and management of virtual organizations (VO based on services from different Clouds. This paper will introduce the main components of such a framework that will innovatively combine the principles of event-driven SOA, REST and ISO/IEC 42010:2007 multiple views and viewpoints in order to provide the required methodology for Cloud-based virtual organization (Cloud-VO engi-neering. The framework will consider the resource concept found in software architectures like REST or RDF as the basic building block of Cloud-VO. and will make use of resources’ URIs to create the Cloud-VO’s resource allocation matrix. While the matrix is used to declare activity-resources relationships, the resource catalogue concept will be introduced as a way to describe the resource in one place, using as many viewpoints as needed, and then to reuse that description for the creation or simulation of different VOs.

  5. Interactive View-Dependent Rendering of Large Isosurfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gregorski, B; Duchaineau, M; Lindstrom, P; Pascucci, V; Joy, K I

    2002-11-19

    We present an algorithm for interactively extracting and rendering isosurfaces of large volume datasets in a view-dependent fashion. A recursive tetrahedral mesh refinement scheme, based on longest edge bisection, is used to hierarchically decompose the data into a multiresolution structure. This data structure allows fast extraction of arbitrary isosurfaces to within user specified view-dependent error bounds. A data layout scheme based on hierarchical space filling curves provides access to the data in a cache coherent manner that follows the data access pattern indicated by the mesh refinement.

  6. Software System for Vocal Rendering of Printed Documents

    Directory of Open Access Journals (Sweden)

    Marian DARDALA

    2008-01-01

    Full Text Available The objective of this paper is to present a software system architecture developed to render the printed documents in a vocal form. On the other hand, in the paper are described the software solutions that exist as software components and are necessary for documents processing as well as for multimedia device controlling used by the system. The usefulness of this system is for people with visual disabilities that can access the contents of documents without that they be printed in Braille system or to exist in an audio form.

  7. An example of quantum imaging: rendering an object undetectable

    CERN Document Server

    Ataman, Stefan

    2016-01-01

    In this paper we propose and analyse a Gedankenexperiment involving three non-linear crystals and two objects inserted in the idler beams. We show that, besides the behaviour that can be extrapolated from previous experiments involving two crystals and one object, we are able to predict a new effect: under certain circumstances, one of the objects can be rendered undetectable to any single detection rate on the signal photons with discarded idler photons. This effect could find applications in future developments of quantum imaging techniques.

  8. An example of quantum imaging: rendering an object undetectable

    Science.gov (United States)

    Ataman, Stefan

    2016-06-01

    In this paper we propose and analyse a Gedankenexperiment involving three non-linear crystals and two objects inserted in the idler beams. We show that, besides the behaviour that can be extrapolated from previous experiments involving two crystals and one object, we are able to predict a new effect: under certain circumstances, one of the objects can be rendered undetectable to any single detection rate on the signal photons with discarded idler photons. This effect could find applications in future developments of quantum imaging techniques.

  9. Horse-shoe lung-rediscovered via volume rendered images

    Directory of Open Access Journals (Sweden)

    Alpa Bharati

    2013-01-01

    Full Text Available Horseshoe lung, usually associated with pulmonary venolobar syndrome, is a rare congenital anomaly involving the fusion of the postero-basal segments of the right and left lungs across the midline. The fused segment or the isthmus lies posterior to the pericardium and anterior to the aorta.The associated pulmonary venolobar syndrome involves anomalous systemic arterial supply and anomlaous systemic venous drainage of the right lung. With the advent of MDCT imaging, we can diagnose this rare condition as well all its associated anomalies non-invasively. Volume-rendered techniques greatly simplify the complex anatomy and provide easy understanding of the same.

  10. Partitioning of biocides between water and inorganic phases of render

    DEFF Research Database (Denmark)

    Urbanczyk, Michal; Bollmann, Ulla E.; Bester, Kai

    The use of biocides as additives for building materials has gained importance in recent years. These biocides are, e.g., applied to renders and paints to prevent them from microbial spoilage. However, these biocides can leach out into the environment. In order to better understand this leaching...... compared. The partitioning constants for calcium carbonate varied between 0.1 (isoproturon) and 1.1 (iodocarb) and 84.6 (dichlorooctylisothiazolinone), respectively. The results for barite, kaolinite and mica were in a similar range and usually the compounds with high partitioning constants for one mineral...

  11. Practical rendering and computation with Direct3D 11

    CERN Document Server

    Zink, Jason; Hoxley, Jack

    2011-01-01

    Practical Rendering and Computation with Direct3D 11 packs in documentation and in-depth coverage of basic and high-level concepts related to using Direct 3D 11 and is a top pick for any serious programming collection. … perfect for a wide range of users. Any interested in computation and multicore models will find this packed with examples and technical applications.-Midwest Book Review, October 2011The authors have generously provided us with an optimal blend of concepts and philosophy, illustrative figures to clarify the more difficult points, and source code fragments to make the ideas con

  12. Virtual Laboratories

    Science.gov (United States)

    Hut, P.

    At the frontier of most areas in science, computer simulations playa central role. The traditional division of natural science into experimental and theoretical investigations is now completely outdated. Instead, theory, simulation, and experimentation form three equally essential aspects, each with its own unique flavor and challenges. Yet, education in computational science is still lagging far behind, and the number of text books in this area is minuscule compared to the many text books on theoretical and experimental science. As a result, many researchers still carry out simulations in a haphazard way, without properly setting up the computational equivalent of a well equipped laboratory. The art of creating such a virtual laboratory, while providing proper extensibility and documentation, is still in its infancy. A new approach is described here, Open Knowledge, as an extension of the notion of Open Source software. Besides open source code, manuals, and primers, an open knowledge project provides simulated dialogues between code developers, thus sharing not only the code, but also the motivations behind the code.

  13. Virtual button interface

    Science.gov (United States)

    Jones, Jake S.

    1999-01-01

    An apparatus and method of issuing commands to a computer by a user interfacing with a virtual reality environment. To issue a command, the user directs gaze at a virtual button within the virtual reality environment, causing a perceptible change in the virtual button, which then sends a command corresponding to the virtual button to the computer, optionally after a confirming action is performed by the user, such as depressing a thumb switch.

  14. Collaborative product and process model: Multiple Viewpoints approach

    CERN Document Server

    Geryville, Hichem; Ouzrout, Yacine; Sapidis, Nikolaos

    2007-01-01

    The design and development of complex products invariably involves many actors who have different points of view on the problem they are addressing, the product being developed, and the process by which it is being developed. The actors' viewpoints approach was designed to provide an organisational framework in which these different perspectives or points of views, and their relationships, could be explicitly gathered and formatted (by actor activity's focus). The approach acknowledges the inevitability of multiple interpretation of product information as different views, promotes gathering of actors' interests, and encourages retrieved adequate information while providing support for integration through PLM and/or SCM collaboration. In this paper, we present our multiple viewpoints approach, and we illustrate it by an industrial example on cyclone vessel product.

  15. Integrating Ontological Data Sources Using Viewpoints-Based Approach

    Directory of Open Access Journals (Sweden)

    Bouchra Boulkroun

    2016-12-01

    Full Text Available Within the development of Internet and intranets, information integration from various data sources becomes increasingly important and more challenging issue. Recently, the trend in data integration has favored the semantic integration using ontologies. However, the existing ontology-based approaches do not support the aspect of data multi-representations, which is important in the development of multi-user applications. The motivation of this paper is to address a novel semantic integration approach based on ontologies and viewpoints paradigms. This contribution combines the advantages of existing ontology-based integration approaches while avoiding their drawbacks. The proposed integration approach is evaluated using query processing. Profiles are introduced to offer answers to users according to their viewpoints and choices.

  16. Floral evolution: Beyond traditional viewpoint of pollinator mediated floral design

    Institute of Scientific and Technical Information of China (English)

    YANG Chunfeng; GUO Youhao

    2005-01-01

    Pollination biology provides new insight for understanding the evolutionary mechanism and process of the existing diversity in floral design of angiosperms. Evolutionary biologists have established some rules and models to try to explain the ubiquitous relationship between pollination system and floral evolution. However, as new techniques have been applied and more and more new pollination events found in recent years, the relationship between pollination system and floral evolution has become less clear. Researchers realized that floral evolution is more complicated and idiosyncratic than simple adaptive models. The traditional viewpoints of pollinator mediated floral design urgently need new reevaluation. This paper attempts to make a brief review of such main opinions and introduce their new insights according to recent studies. Finally, we also give some suggestions for future study by reviewing several new viewpoints about floral evolution.

  17. Virtual goods recommendations in virtual worlds.

    Science.gov (United States)

    Chen, Kuan-Yu; Liao, Hsiu-Yu; Chen, Jyun-Hung; Liu, Duen-Ren

    2015-01-01

    Virtual worlds (VWs) are computer-simulated environments which allow users to create their own virtual character as an avatar. With the rapidly growing user volume in VWs, platform providers launch virtual goods in haste and stampede users to increase sales revenue. However, the rapidity of development incurs virtual unrelated items which will be difficult to remarket. It not only wastes virtual global companies' intelligence resources, but also makes it difficult for users to find suitable virtual goods fit for their virtual home in daily virtual life. In the VWs, users decorate their houses, visit others' homes, create families, host parties, and so forth. Users establish their social life circles through these activities. This research proposes a novel virtual goods recommendation method based on these social interactions. The contact strength and contact influence result from interactions with social neighbors and influence users' buying intention. Our research highlights the importance of social interactions in virtual goods recommendation. The experiment's data were retrieved from an online VW platform, and the results show that the proposed method, considering social interactions and social life circle, has better performance than existing recommendation methods.

  18. Virtual Goods Recommendations in Virtual Worlds

    Directory of Open Access Journals (Sweden)

    Kuan-Yu Chen

    2015-01-01

    Full Text Available Virtual worlds (VWs are computer-simulated environments which allow users to create their own virtual character as an avatar. With the rapidly growing user volume in VWs, platform providers launch virtual goods in haste and stampede users to increase sales revenue. However, the rapidity of development incurs virtual unrelated items which will be difficult to remarket. It not only wastes virtual global companies’ intelligence resources, but also makes it difficult for users to find suitable virtual goods fit for their virtual home in daily virtual life. In the VWs, users decorate their houses, visit others’ homes, create families, host parties, and so forth. Users establish their social life circles through these activities. This research proposes a novel virtual goods recommendation method based on these social interactions. The contact strength and contact influence result from interactions with social neighbors and influence users’ buying intention. Our research highlights the importance of social interactions in virtual goods recommendation. The experiment’s data were retrieved from an online VW platform, and the results show that the proposed method, considering social interactions and social life circle, has better performance than existing recommendation methods.

  19. Surfaces in 4-space from the affine differential geometry viewpoint

    OpenAIRE

    Luis Florial Espinoza Sánchez

    2014-01-01

    In this thesis, we study locally strictly convex surfaces from the affine differential viewpoint and generalize some tools for locally strictly submanifolds of codimension 2. We introduce a family of affine metrics on a locally strictly convex surface M in affine 4-space. Then, we define the symmetric and antisymmetric equiaffine planes associated with each metric. We show that if M is immersed in a locally atrictly convex hyperquadric, then the symmetric and the antisymmetric planes coincid...

  20. Kepler Problem in Hamiltonian Formulation Discussed from Topological Viewpoint

    Institute of Scientific and Technical Information of China (English)

    XU Gong-Ou; XU Ming-Jie; YANG Ya-Tian

    2005-01-01

    @@ The Kepler problem in Hamiltonian formulation is discussed from a topological viewpoint. Topological properties for a set of cases designated with conserved quantities l, e and E(l, e) (0 ≤ e < 1) are expressed with actionangle variables. The involved canonical transformations are all carried out with classical Poisson brackets. Thus it is possible to extend such a formulation to corresponding quantum-mechanical study under quasi-classical conditions.

  1. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering

    KAUST Repository

    Sicat, Ronell Barrera

    2014-12-31

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined in the 4D domain jointly comprising the 3D volume and its 1D intensity range. Crucially, the computation of sparse pdf volumes exploits data coherence in 4D, resulting in a sparse representation with surprisingly low storage requirements. At run time, we dynamically apply transfer functions to the pdfs using simple and fast convolutions. Whereas standard low-pass filtering and down-sampling incur visible differences between resolution levels, the use of pdfs facilitates consistent results independent of the resolution level used. We describe the efficient out-of-core computation of large-scale sparse pdf volumes, using a novel iterative simplification procedure of a mixture of 4D Gaussians. Finally, our data structure is optimized to facilitate interactive multi-resolution volume rendering on GPUs.

  2. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering.

    Science.gov (United States)

    Sicat, Ronell; Krüger, Jens; Möller, Torsten; Hadwiger, Markus

    2014-12-01

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined in the 4D domain jointly comprising the 3D volume and its 1D intensity range. Crucially, the computation of sparse pdf volumes exploits data coherence in 4D, resulting in a sparse representation with surprisingly low storage requirements. At run time, we dynamically apply transfer functions to the pdfs using simple and fast convolutions. Whereas standard low-pass filtering and down-sampling incur visible differences between resolution levels, the use of pdfs facilitates consistent results independent of the resolution level used. We describe the efficient out-of-core computation of large-scale sparse pdf volumes, using a novel iterative simplification procedure of a mixture of 4D Gaussians. Finally, our data structure is optimized to facilitate interactive multi-resolution volume rendering on GPUs.

  3. Fast polyhedral cell sorting for interactive rendering of unstructured grids

    Energy Technology Data Exchange (ETDEWEB)

    Combra, J; Klosowski, J T; Max, N; Silva, C T; Williams, P L

    1998-10-30

    Direct volume rendering based on projective methods works by projecting, in visibility order, the polyhedral cells of a mesh onto the image plane, and incrementally compositing the cell's color and opacity into the final image. Crucial to this method is the computation of a visibility ordering of the cells. If the mesh is ''well-behaved'' (acyclic and convex), then the MPVO method of Williams provides a very fast sorting algorithm; however, this method only computes an approximate ordering in general datasets, resulting in visual artifacts when rendered. A recent method of Silva et al. removed the assumption that the mesh is convex, by means of a sweep algorithm used in conjunction with the MPVO method; their algorithm is substantially faster than previous exact methods for general meshes. In this paper we propose a new technique, which we call BSP-XMPVO, which is based on a fast and simple way of using binary space partitions on the boundary elements of the mesh to augment the ordering produced by MPVO. Our results are shown to be orders of magnitude better than previous exact methods of sorting cells.

  4. Non-Photorealistic Rendering in Chinese Painting of Animals

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A set of algorithms is proposed in this paper to automatically transform 3D animal models to Chinese painting style. Inspired by real painting process in Chinese painting of animals, we divide the whole rendering process into two parts: borderline stroke making and interior shading. In borderline stroke making process we first find 3D model silhouettes in real-time depending on the viewing direction of a user. After retrieving silhouette information from all model edges, a stroke linking mechanism is applied to link these independent edges into a long stroke. Finally we grow a plain thin silhouette line to a stylus stroke with various widths at each control point and a 2D brush model is combined with it to simulate a Chinese painting stroke. In the interior shading pipeline, three stages are used to convert a Gouraud-shading image to a Chinese painting style image: color quantization, ink diffusion and box filtering. The color quantization stage assigns all pixels in an image into four color levels and each level represents a color layer in a Chinese painting. Ink diffusion stage is used to transfer inks and water between different levels and to grow areas in an irregular way. The box filtering stage blurs sharp borders between different levels to embellish the appearance of final interior shading image. In addition to automatic rendering, an interactive Chinese painting system which is equipped with friendly input devices can be also combined to generate more artistic Chinese painting images manually.

  5. Protein and mineral characterisation of rendered meat and bone meal.

    Science.gov (United States)

    Buckley, M; Penkman, K E H; Wess, T J; Reaney, S; Collins, M J

    2012-10-01

    We report the characterisation of meat and bone meal (MBM) standards (Set B-EFPRA) derived from cattle, sheep, pig and chicken, each rendered at four different temperatures (133, 137, 141 and 145 °C). The standards, prepared for an EU programme STRATFEED (to develop new methodologies for the detection and quantification of illegal addition of mammalian tissues in feeding stuffs), have been widely circulated and used to assess a range of methods for identification of the species composition of MBM. The overall state of mineral alteration and protein preservation as a function of temperature was monitored using small angle X-ray diffraction (SAXS), amino acid composition and racemization analyses. Progressive increases in protein damage and mineral alteration in chicken and cattle standards was observed. In the case of sheep and pig, there was greater damage to the proteins and alteration of the minerals at the lowest treatment temperature (133 °C), suggesting that the thermal treatments must have been compromised in some way. This problem has probably impacted upon the numerous studies which tested methods against these heat treatments. We use protein mass spectrometric methods to explore if thermostable proteins could be used to identify rendered MBM. In more thermally altered samples, so-called 'thermostable' proteins such as osteocalcin which has been proposed as a ideal target to speciate MBM were no longer detectable, but the structural protein type I collagen could be used to differentiate all four species, even in the most thermally altered samples.

  6. 75 FR 27119 - ViewPoint Financial Group, Inc., Plano, Texas; Approval of Conversion Application

    Science.gov (United States)

    2010-05-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE TREASURY Office of Thrift Supervision ViewPoint Financial Group, Inc., Plano, Texas; Approval of Conversion... application of ViewPoint MHC and ViewPoint Bank, Plano, Texas, to convert to the stock form of...

  7. Effect of familiarity and viewpoint on face recognition in chimpanzees.

    Science.gov (United States)

    Parr, Lisa A; Siebert, Erin; Taubert, Jessica

    2011-01-01

    Numerous studies have shown that familiarity strongly influences how well humans recognize faces. This is particularly true when faces are encountered across a change in viewpoint. In this situation, recognition may be accomplished by matching partial or incomplete information about a face to a stored representation of the known individual, whereas such representations are not available for unknown faces. Chimpanzees, our closest living relatives, share many of the same behavioral specializations for face processing as humans, but the influence of familiarity and viewpoint have never been compared in the same study. Here, we examined the ability of chimpanzees to match the faces of familiar and unfamiliar conspecifics in their frontal and 3/4 views using a computerized task. Results showed that, while chimpanzees were able to accurately match both familiar and unfamiliar faces in their frontal orientations, performance was significantly impaired only when unfamiliar faces were presented across a change in viewpoint. Therefore, like in humans, face processing in chimpanzees appears to be sensitive to individual familiarity. We propose that familiarization is a robust mechanism for strengthening the representation of faces and has been conserved in primates to achieve efficient individual recognition over a range of natural viewing conditions.

  8. REDES SOCIALES VIRTUALES Y LA BIOÉTICA VIRTUAL SOCIAL NETWORKS AND BIOETHICS

    Directory of Open Access Journals (Sweden)

    Jorge Arturo Pérez Pérez

    2011-06-01

    Full Text Available RESUMEN:La investigación tiende a indagar por las condiciones psicológicas (obsesivas, socio – familiares, fisiológicas y emocionales de los estudiantes de la Universidad de San Buenaventura –Medellín de mes de agosto de 2010, que tienden a destinar parte de su tiempo a las Redes Sociales Virtuales y hacer una reflexión desde la Bioética frente al tema.Abstract:This piece of research tends to inquire into the (obsessive psychological, socio-family, physiological, and emotional conditions of the students at Saint Bonaventure University, Medellin Branch, back in the month of August 2010, who have the tendency to spend their free time in the Virtual Social Networks and then make an analysis of this issue, from the Bioethical viewpoint.

  9. Virtual Trackballs Revisited

    DEFF Research Database (Denmark)

    Henriksen, Knud; Sporring, Jon; Hornbæk, Kasper

    2004-01-01

    Rotation of three-dimensional objects by a two-dimensional mouse is a typical task in computer-aided design, operation simulations, and desktop virtual reality. The most commonly used rotation technique is a virtual trackball surrounding the object and operated by the mouse pointer. This article...... reviews and provides a mathematical foundation for virtual trackballs. The first, but still popular, virtual trackball was described by Chen et al. [CHECK END OF SENTENCE]. We show that the virtual trackball by Chen et al. does not rotate the object along the intended great circular arc on the virtual...... trackball and we give a correction. Another popular virtual trackball is Shoemake's quaternion implementation [CHECK END OF SENTENCE], which we show to be a special case of the virtual trackball by Chen et al.. Shoemake extends the scope of the virtual trackball to the full screen. Unfortunately, Shoemake...

  10. "Virtual unwrapping" of a mummified hand.

    Science.gov (United States)

    Winder, R J; Glover, W; Golz, T; Wulf, J; McClure, S; Cairns, H; Elliott, M

    2006-01-01

    The purpose of this work is to demonstrate the feasibility of medical virtual reality technologies in the investigation of a mummified hand. The Ulster Museum obtained the mummy hand, which originated from Thebes, without any identifying information. The mummified hand was investigated using conventional X-ray and 3D multi-slice Computed Tomography (CT). Imaging revealed a range of fractures of the wrist, metacarpals and phalanges whilst 3D CT demonstrated internal structures using volume rendering. The absence of any features of bone healing at the fracture sites would imply that they occurred just prior to death or in the mummified state possibly during excavation. Conventional X-ray imaging indicated that the hand, although small, was likely to have originated from an adult. Medical imaging and virtual reality display will enable us to produce a rapid prototyped model using fused deposition technology. Therefore, further paleopathological research can be performed on the replica without the need to handle the original specimen.

  11. Virtual environments for scene of crime reconstruction and analysis

    Science.gov (United States)

    Howard, Toby L. J.; Murta, Alan D.; Gibson, Simon

    2000-02-01

    This paper describes research conducted in collaboration with Greater Manchester Police (UK), to evalute the utility of Virtual Environments for scene of crime analysis, forensic investigation, and law enforcement briefing and training. We present an illustrated case study of the construction of a high-fidelity virtual environment, intended to match a particular real-life crime scene as closely as possible. We describe and evaluate the combination of several approaches including: the use of the Manchester Scene Description Language for constructing complex geometrical models; the application of a radiosity rendering algorithm with several novel features based on human perceptual consideration; texture extraction from forensic photography; and experiments with interactive walkthroughs and large-screen stereoscopic display of the virtual environment implemented using the MAVERIK system. We also discuss the potential applications of Virtual Environment techniques in the Law Enforcement and Forensic communities.

  12. Excellent color rendering indexes of multi-package white LEDs.

    Science.gov (United States)

    Oh, Ji Hye; Yang, Su Ji; Sung, Yeon-Goog; Do, Y R

    2012-08-27

    This study introduces multi-package white light-emitting diodes (LEDs) system with the ability to realize high luminous efficacy and an excellent color rendering index (CRI, R a) using the R B,M A B,M G B,M C B (R B,M A B,M G B,M denoted as a long-pass dichroic filter (LPDF)-capped, monochromatic red, amber and green phosphor converted-LED (pc-LED) pumped by a blue LED chip, and C B denoted as a cyan and blue mixed pc-LED pumped by a blue LED) system. The luminous efficacy and color rendering index (CRI) of multi-package white LED systems are compared while changing the concentration of the cyan phosphor used in the paste of a cyan-blue LED package and the driving current of individual LEDs in multi-package white LEDs at correlated color temperatures (CCTs) ranging from 6,500 K (cold white) to 2,700 K (warm white) using a set of eight CCTs as specified by the American National Standards Institute (ANSI) standard number C78.377-2008. A R B,M A B,M G B,M C B white LED system provides high luminous efficacy (≥ 96 lm/W) and a color rendering index (≥ 91) encompassing the complete CCT range. We also compare the optical properties of the R B,M A B,M G B,M C B system with those of the R B,M A B,M G B,M B and RAGB (red, amber, green, and blue semiconductor-type narrow-spectrum-band LEDs) systems. It can be expected that the cyan color added to a blue LED in multi-package white LEDs based on LPDF-capped, phosphor-converted monochromatic LEDs will meet the needs of the high-quality, highly efficient, full-color white LED lighting market in the near future.

  13. 9 CFR 319.703 - Rendered animal fat or mixture thereof.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Rendered animal fat or mixture thereof... INSPECTION AND CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Fats, Oils, Shortenings § 319.703 Rendered animal fat or mixture thereof. “Rendered Animal Fat,” or any mixture of...

  14. Man, mind, and machine: the past and future of virtual reality simulation in neurologic surgery.

    Science.gov (United States)

    Robison, R Aaron; Liu, Charles Y; Apuzzo, Michael L J

    2011-11-01

    To review virtual reality in neurosurgery, including the history of simulation and virtual reality and some of the current implementations; to examine some of the technical challenges involved; and to propose a potential paradigm for the development of virtual reality in neurosurgery going forward. A search was made on PubMed using key words surgical simulation, virtual reality, haptics, collision detection, and volumetric modeling to assess the current status of virtual reality in neurosurgery. Based on previous results, investigators extrapolated the possible integration of existing efforts and potential future directions. Simulation has a rich history in surgical training, and there are numerous currently existing applications and systems that involve virtual reality. All existing applications are limited to specific task-oriented functions and typically sacrifice visual realism for real-time interactivity or vice versa, owing to numerous technical challenges in rendering a virtual space in real time, including graphic and tissue modeling, collision detection, and direction of the haptic interface. With ongoing technical advancements in computer hardware and graphic and physical rendering, incremental or modular development of a fully immersive, multipurpose virtual reality neurosurgical simulator is feasible. The use of virtual reality in neurosurgery is predicted to change the nature of neurosurgical education, and to play an increased role in surgical rehearsal and the continuing education and credentialing of surgical practitioners. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Through Teachers’ Eyes: The Use of Virtual Classrooms in ELT

    Directory of Open Access Journals (Sweden)

    Jairo Enrique Castañeda

    2012-12-01

    Full Text Available The use of virtual environments to support as well as to complement language teaching and learning processes is becoming a recurrent practice and sometimes policy in several educational institutions. This paper reports the results of an inquiry carried out at the language center of a private university in Bogotá. Those results intended to describe EFL teachers’ viewpoints regarding the promotion of autonomous, collaborative, and meaningful learning through the use of virtual classrooms in the teaching of English as a foreign language. Findings show that the promotion of these three types of learning through the use of virtual classrooms still represents challenges in the context in which this study was carried out.

  16. Efficient Unbiased Rendering using Enlightened Local Path Sampling

    DEFF Research Database (Denmark)

    Kristensen, Anders Wang

    . The downside to using these algorithms is that they can be slow to converge. Due to the nature of Monte Carlo methods, the results are random variables subject to variance. This manifests itself as noise in the images, which can only be reduced by generating more samples. The reason these methods are slow...... is because of a lack of eeffective methods of importance sampling. Most global illumination algorithms are based on local path sampling, which is essentially a recipe for constructing random walks. Using this procedure paths are built based on information given explicitly as part of scene description......, such as the location of the light sources or cameras, or the re flection models at each point. In this work we explore new methods of importance sampling paths. Our idea is to analyze the scene before rendering and compute various statistics that we use to improve importance sampling. The first of these are adjoint...

  17. Real-time Flame Rendering with GPU and CUDA

    Directory of Open Access Journals (Sweden)

    Wei Wei

    2011-02-01

    Full Text Available This paper proposes a method of flame simulation based on Lagrange process and chemical composition, which was non-grid and the problems associated with there grids were overcome. The turbulence movement of flame was described by Lagrange process and chemical composition was added into flame simulation which increased the authenticity of flame. For real-time applications, this paper simplified the EMST model. GPU-based particle system combined with OpenGL VBO and PBO unique technology was used to accelerate finally, the speed of vertex and pixel data interaction between CPU and GPU increased two orders of magnitude, frame rate of rendering increased by 30%, which achieved fast dynamic flame real-time simulation. For further real-time applications, this paper presented a strategy to implement flame simulation with CUDA on GPU, which achieved a speed up to 2.5 times the previous implementation.

  18. Depth inloop resampling using dilation filter for free viewpoint video system

    Science.gov (United States)

    Lee, Seok; Lee, Seungsin; Wey, Hocheon; Lee, Jaejoon; Park, Dusik

    2013-03-01

    A depth dilation filter is proposed for free viewpoint video system based on mixed resolution multi-view video plus depth (MVD). By applying gray scale dilation filter to depth images, foreground regions are extended to background region, and synthesis artifacts occur out of boundary edge. Thus, objective and subjective quality of view synthesis result is improved. A depth dilation filter is applied to inloop resampling part in encoding/decoding, and post processing part after decoding. Accurate view synthesis is important in virtual view generation for autostereoscopic display, moreover there are many coding tools which use view synthesis to reduce interview redundancy in 3D video coding such as view synthesis prediction (VSP) and depth based motion vector prediction (DMVP), and compression efficiency can be improved by accurate view synthesis. Coding and synthesis experiments are performed for performance evaluation of a dilation filter with MPEG test sequences. Dilation filter was implemented on the top of the MPEG reference software for AVC based 3D video coding. By applying a depth dilation filter, BD-rate gains of 0.5% and 6.0% in terms of PSNR of decoded views and synthesized views, respectively.

  19. Distributed Dimensonality-Based Rendering of LIDAR Point Clouds

    Science.gov (United States)

    Brédif, M.; Vallet, B.; Ferrand, B.

    2015-08-01

    Mobile Mapping Systems (MMS) are now commonly acquiring lidar scans of urban environments for an increasing number of applications such as 3D reconstruction and mapping, urban planning, urban furniture monitoring, practicability assessment for persons with reduced mobility (PRM)... MMS acquisitions are usually huge enough to incur a usability bottleneck for the increasing number of non-expert user that are not trained to process and visualize these huge datasets through specific softwares. A vast majority of their current need is for a simple 2D visualization that is both legible on screen and printable on a static 2D medium, while still conveying the understanding of the 3D scene and minimizing the disturbance of the lidar acquisition geometry (such as lidar shadows). The users that motivated this research are, by law, bound to precisely georeference underground networks for which they currently have schematics with no or poor absolute georeferencing. A solution that may fit their needs is thus a 2D visualization of the MMS dataset that they could easily interpret and on which they could accurately match features with their user datasets they would like to georeference. Our main contribution is two-fold. First, we propose a 3D point cloud stylization for 2D static visualization that leverages a Principal Component Analysis (PCA)-like local geometry analysis. By skipping the usual and error-prone estimation of a ground elevation, this rendering is thus robust to non-flat areas and has no hard-to-tune parameters such as height thresholds. Second, we implemented the corresponding rendering pipeline so that it can scale up to arbitrary large datasets by leveraging the Spark framework and its Resilient Distributed Dataset (RDD) and Dataframe abstractions.

  20. On-the-Fly Decompression and Rendering of Multiresolution Terrain

    Energy Technology Data Exchange (ETDEWEB)

    Lindstrom, P; Cohen, J D

    2009-04-02

    We present a streaming geometry compression codec for multiresolution, uniformly-gridded, triangular terrain patches that supports very fast decompression. Our method is based on linear prediction and residual coding for lossless compression of the full-resolution data. As simplified patches on coarser levels in the hierarchy already incur some data loss, we optionally allow further quantization for more lossy compression. The quantization levels are adaptive on a per-patch basis, while still permitting seamless, adaptive tessellations of the terrain. Our geometry compression on such a hierarchy achieves compression ratios of 3:1 to 12:1. Our scheme is not only suitable for fast decompression on the CPU, but also for parallel decoding on the GPU with peak throughput over 2 billion triangles per second. Each terrain patch is independently decompressed on the fly from a variable-rate bitstream by a GPU geometry program with no branches or conditionals. Thus we can store the geometry compressed on the GPU, reducing storage and bandwidth requirements throughout the system. In our rendering approach, only compressed bitstreams and the decoded height values in the view-dependent 'cut' are explicitly stored on the GPU. Normal vectors are computed in a streaming fashion, and remaining geometry and texture coordinates, as well as mesh connectivity, are shared and re-used for all patches. We demonstrate and evaluate our algorithms on a small prototype system in which all compressed geometry fits in the GPU memory and decompression occurs on the fly every rendering frame without any cache maintenance.

  1. Using a virtual world for robot planning

    Science.gov (United States)

    Benjamin, D. Paul; Monaco, John V.; Lin, Yixia; Funk, Christopher; Lyons, Damian

    2012-06-01

    We are building a robot cognitive architecture that constructs a real-time virtual copy of itself and its environment, including people, and uses the model to process perceptual information and to plan its movements. This paper describes the structure of this architecture. The software components of this architecture include PhysX for the virtual world, OpenCV and the Point Cloud Library for visual processing, and the Soar cognitive architecture that controls the perceptual processing and task planning. The RS (Robot Schemas) language is implemented in Soar, providing the ability to reason about concurrency and time. This Soar/RS component controls visual processing, deciding which objects and dynamics to render into PhysX, and the degree of detail required for the task. As the robot runs, its virtual model diverges from physical reality, and errors grow. The Match-Mediated Difference component monitors these errors by comparing the visual data with corresponding data from virtual cameras, and notifies Soar/RS of significant differences, e.g. a new object that appears, or an object that changes direction unexpectedly. Soar/RS can then run PhysX much faster than real-time and search among possible future world paths to plan the robot's actions. We report experimental results in indoor environments.

  2. Synthesis of Virtual Environments for Aircraft Community Noise Impact Studies

    Science.gov (United States)

    Rizzi, Stephen A.; Sullivan, Brenda M.

    2005-01-01

    A new capability has been developed for the creation of virtual environments for the study of aircraft community noise. It is applicable for use with both recorded and synthesized aircraft noise. When using synthesized noise, a three-stage process is adopted involving non-real-time prediction and synthesis stages followed by a real-time rendering stage. Included in the prediction-based source noise synthesis are temporal variations associated with changes in operational state, and low frequency fluctuations that are present under all operating conditions. Included in the rendering stage are the effects of spreading loss, absolute delay, atmospheric absorption, ground reflections, and binaural filtering. Results of prediction, synthesis and rendering stages are presented.

  3. Virtual Reality in Psychology

    National Research Council Canada - National Science Library

    Nigel Foreman

    2009-01-01

    The benefits of using virtual environments (VEs) in psychology arise from the fact that movements in virtual space, and accompanying perceptual changes, are treated by the brain in much the same way as those in equivalent real space...

  4. Virtual reference services

    OpenAIRE

    Márdero Arellano, Miguel Ángel

    2001-01-01

    Analysis of virtual reference services, their standandars and new technologies that have changed the tradicional practice at the library’s reference desk. Major American virtual reference services initiatives and their characteristics are described.

  5. Cross-modal object recognition is viewpoint-independent.

    Directory of Open Access Journals (Sweden)

    Simon Lacey

    Full Text Available BACKGROUND: Previous research suggests that visual and haptic object recognition are viewpoint-dependent both within- and cross-modally. However, this conclusion may not be generally valid as it was reached using objects oriented along their extended y-axis, resulting in differential surface processing in vision and touch. In the present study, we removed this differential by presenting objects along the z-axis, thus making all object surfaces more equally available to vision and touch. METHODOLOGY/PRINCIPAL FINDINGS: Participants studied previously unfamiliar objects, in groups of four, using either vision or touch. Subsequently, they performed a four-alternative forced-choice object identification task with the studied objects presented in both unrotated and rotated (180 degrees about the x-, y-, and z-axes orientations. Rotation impaired within-modal recognition accuracy in both vision and touch, but not cross-modal recognition accuracy. Within-modally, visual recognition accuracy was reduced by rotation about the x- and y-axes more than the z-axis, whilst haptic recognition was equally affected by rotation about all three axes. Cross-modal (but not within-modal accuracy correlated with spatial (but not object imagery scores. CONCLUSIONS/SIGNIFICANCE: The viewpoint-independence of cross-modal object identification points to its mediation by a high-level abstract representation. The correlation between spatial imagery scores and cross-modal performance suggest that construction of this high-level representation is linked to the ability to perform spatial transformations. Within-modal viewpoint-dependence appears to have a different basis in vision than in touch, possibly due to surface occlusion being important in vision but not touch.

  6. Virtual reality exposure therapy

    OpenAIRE

    Rothbaum, BO; Hodges, L; Kooper, R

    1997-01-01

    It has been proposed that virtual reality (VR) exposure may be an alternative to standard in vivo exposure. Virtual reality integrates real-time computer graphics, body tracking devices, visual displays, and other sensory input devices to immerse a participant in a computer- generated virtual environment. Virtual reality exposure is potentially an efficient and cost-effective treatment of anxiety disorders. VR exposure therapy reduced the fear of heights in the first control...

  7. The Virtual Lab System

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A virtual lab system is the simulation of real devices and experiments using computer and network tech-nology. It can make users do experiments easily, observe experiment phenomena and results through the remote termi-nal. Consequently, users can get final results to verify relative theory. The article analyses the features of virtual labsystems. A real virtual lab system named "Multimedia Virtual Lab for Digital Circuit Logic Design (MVLDCLD) "which has been developed by the authors and their group is also presented.

  8. Virtual currencies- Real opportunities?

    OpenAIRE

    Selldahl, Sara

    2013-01-01

    The European Central Bank defines virtual currencies as ”unregulated, digital money, which is issued and usually controlled by its developers, and used and accepted among the members of a specific virtual community.” (European Central Bank, 2012, p. 5) The interest in virtual currencies has increased immensely over the last few years as they become increasingly prevalent in our society across many different industries. Up until now, the field of virtual currencies has been mainly uncharted ...

  9. Finite stage asymmetric repeated games: Both players' viewpoints

    KAUST Repository

    Li, Lichun

    2017-01-05

    In asymmetric zero-sum games, one player has superior information about the game over the other. It is known that the informed players (maximizer) face the tradeoff of exploiting its superior information at the cost of revealing its superior information, but the basic point of the uninformed player (minimizer)\\'s decision making remains unknown. This paper studies the finite stage asymmetric repeated games from both players\\' viewpoints, and derives that not only security strategies but also the opponents\\' corresponding best responses depends only on the informed player\\'s history action sequences. Moreover, efficient LP formulations to compute both player\\'s security strategies are provided.

  10. Lumped and distributed passive networks a generalized and advanced viewpoint

    CERN Document Server

    Wohlers, M Ronald; Declaris, Nicholas

    1969-01-01

    Lumped and Distributed Passive Networks: A Generalized and Advanced Viewpoint considers the mathematical study of a subset of passive linear operators. This five-chapter focuses on the questions of analysis and representation of such operators and illustrates the results of these analyses by obtaining some of the limitations that are imposed on the performance of passive systems. The first two chapters deal with the structure of general linear passive operators. These chapters specifically look into the theory of distributions, called generalized functions. The third and fourth chapters illust

  11. A visual graphic/haptic rendering model for hysteroscopic procedures.

    Science.gov (United States)

    Lim, Fabian; Brown, Ian; McColl, Ryan; Seligman, Cory; Alsaraira, Amer

    2006-03-01

    Hysteroscopy is an extensively popular option in evaluating and treating women with infertility. The procedure utilises an endoscope, inserted through the vagina and cervix to examine the intra-uterine cavity via a monitor. The difficulty of hysteroscopy from the surgeon's perspective is the visual spatial perception of interpreting 3D images on a 2D monitor, and the associated psychomotor skills in overcoming the fulcrum-effect. Despite the widespread use of this procedure, current qualified hysteroscopy surgeons have not been trained the fundamentals through an organised curriculum. The emergence of virtual reality as an educational tool for this procedure, and for other endoscopic procedures, has undoubtedly raised interests. The ultimate objective is for the inclusion of virtual reality training as a mandatory component for gynaecologic endoscopy training. Part of this process involves the design of a simulator, encompassing the technical difficulties and complications associated with the procedure. The proposed research examines fundamental hysteroscopy factors, current training and accreditation, and proposes a hysteroscopic simulator design that is suitable for educating and training.

  12. Virtual Reference Services.

    Science.gov (United States)

    Brewer, Sally

    2003-01-01

    As the need to access information increases, school librarians must create virtual libraries. Linked to reliable reference resources, the virtual library extends the physical collection and library hours and lets students learn to use Web-based resources in a protected learning environment. The growing number of virtual schools increases the need…

  13. A Virtual Class Calculus

    DEFF Research Database (Denmark)

    Ernst, Erik; Ostermann, Klaus; Cook, William Randall

    2006-01-01

    model for virtual classes has been a long-standing open question. This paper presents a virtual class calculus, vc, that captures the essence of virtual classes in these full-fledged programming languages. The key contributions of the paper are a formalization of the dynamic and static semantics of vc...

  14. Virtual Reality: An Overview.

    Science.gov (United States)

    Franchi, Jorge

    1994-01-01

    Highlights of this overview of virtual reality include optics; interface devices; virtual worlds; potential applications, including medicine and archaeology; problems, including costs; current research and development; future possibilities; and a listing of vendors and suppliers of virtual reality products. (Contains 11 references.) (LRW)

  15. Mobile Virtual Environments in Pervasive Computing

    Science.gov (United States)

    Lazem, Shaimaa; Abdel-Hamid, Ayman; Gračanin, Denis; Adams, Kevin P.

    Recently, human computer interaction has shifted from traditional desktop computing to the pervasive computing paradigm where users are engaged with everywhere and anytime computing devices. Mobile virtual environments (MVEs) are an emerging research area that studies the deployment of virtual reality applications on mobile devices. MVEs present additional challenges to application developers due to the restricted resources of the mobile devices, in addition to issues that are specific to wireless computing, such as limited bandwidth, high error rate and handoff intervals. Moreover, adaptive resource allocation is a key issue in MVEs where user interactions affect system resources, which, in turn, affects the user’s experience. Such interplay between the user and the system can be modelled using game theory. This chapter presents MVEs as a real-time interactive distributed system, and investigates the challenges in designing and developing a remote rendering prefetching application for mobile devices. Furthermore, we introduce game theory as a tool for modelling decision-making in MVEs by describing a game between the remote rendering server and the mobile client.

  16. Rendering mortars in Medina Azahara, Part II: Material characterization and alteration causes

    Directory of Open Access Journals (Sweden)

    Blanco-Varela, M. T.

    1997-06-01

    Full Text Available In the present work, the depicted coat that covers some of the mortars exposed to weathering in the Medina Azahara archaeological site is .studied. That coat is characterized from the compositional and physical viewpoint and the main causes for its decay are determined. The depicted coat is formed by cal cite and iron oxides. It is quite compact and homogeneous. It is approximately 0.1 to 1 mm thick. The depicted coats supposed by lime mortars have CaCO3 deposits over polychromy rests. Depicted coats supported by gypsum mortars or mixed lime and gypsum mortars have gypsum deposits over polychromy rests. The processes of rendering mortars dissolution and the later crystallization of salts on their surface, together with biological growth, are the main causes of the decay of the depicted coats.

    En el presente trabajo se estudia la capa de policromía que recubre algunos de los morteros conservados a la intemperie en la ciudad de Medina Azahara. Dicha capa se caracteriza desde el punto de vista composicional y físico, determinándose las principales causas de su deterioro. La capa de policromía está formada por calcita y óxidos de hierro. Dicha capa es bastante homogénea y compacta. Su espesor es de 0,1 a 1 mm aproximadamente. Las capas de pintura sustentadas por morteros de cal tienen un depósito de CaCO sobre los restos de policromía. Las capas de pintura sustentadas por morteros de yeso o bastardos de cal y yeso tienen depósitos de yeso sobre los restos de policromía. Los procesos de disolución de los revocos y la posterior cristalización de las sales en su superficie, junto con la colonización biológica, son las principales causas de deterioro de la capa de policromía de su superficie.

  17. Rhazes viewpoints about causes, diagnosis, treatment and prognosis of gout.

    Science.gov (United States)

    Tabatabaei, Seyed Mahmoud; Tabatabaei, Seyed Mohammad Ali; Zamani, Mohammad Mahdi; Sabetkish, Nastaran; Roshani, Farnaz

    2012-01-01

    Gout, a medical condition of acute inflammatory joint disorders, has been recognized from the antiquity. However, the name of Rhazes, a Persian historic physician who has described the etiology, signs, symptoms, epidemiology, treatment and prevention of this malady more than a thousand year ago, hasn't been taken into consideration appropriately. In this article, we studied and reported several chapters of Alhawi which is considered the most important Rhazes's medical textbook, focussing on his hypotheses because he has described this disease more manifestly. His original manuscripts are originally written in Arabic and they hadn't been translated to Persian until 1998. We intend to compare Rhazes opinions about gout with those of the literature in the area of rheumatology. According to our findings, Rhazes documented the symptoms of gout and categorized them scientifically. His insights about the treatment of gout, side effects of pharmacotherapy and management of the patients are so interesting and wonderful. Generally most of Rhazes viewpoints about gout are correct and compatible with recent findings. More investigation on Rhazes' viewpoints can guide us to propose more reliable hypothesis and schematize cost effective studies by delving into past medical records.

  18. Virtual positron emission tomography/computed tomography-bronchoscopy: possibilities, advantages and limitations of clinical application

    Energy Technology Data Exchange (ETDEWEB)

    Seemann, Marcus D. [University of Magdeburg, Department of Radiology and Nuclear Medicine, Magdeburg (Germany); Schaefer, Juergen F. [Eberhard-Karls University, Department of Diagnostic Radiology, Tuebingen (Germany); Englmeier, Karl-Hans [Institute of Medical Informatics, GSF-National Research Center for Environment and Health, Neuherberg (Germany)

    2007-03-15

    The aim of this study was to demonstrate the possibilities, advantages and limitations of virtual bronchoscopy using data sets from positron emission tomography (PET) and computed tomography (CT). Twelve consecutive patients with lung cancer underwent PET/CT. PET was performed with F-18-labelled 2-[fluorine-18]-fluoro-2-deoxy-D-glucose ({sup 18}F-FDG). The tracheobronchial system was segmented with a volume-growing algorithm, using the CT data sets, and visualized with a shaded-surface rendering method. The primary tumours and the lymph node metastases were segmented for virtual CT-bronchoscopy using the CT data set and for virtual PET/CT-bronchoscopy using the PET/CT data set. Virtual CT-bronchoscopy using the low-dose or diagnostic CT facilitates the detection of anatomical/morphological structure changes of the tracheobronchial system. Virtual PET/CT-bronchoscopy was superior to virtual CT-bronchoscopy in the detection of lymph node metastases (P=0.001), because it uses the CT information and the molecular/metabolic information from PET. Virtual PET/CT-bronchoscopy with a transparent colour-coded shaded-surface rendering model is expected to improve the diagnostic accuracy of identification and characterization of malignancies, assessment of tumour staging, differentiation of viable tumour tissue from atelectases and scars, verification of infections, evaluation of therapeutic response and detection of an early stage of recurrence that is not detectable or is misjudged in comparison with virtual CT-bronchoscopy. (orig.)

  19. Moisture Transfer through Facades Covered with Organic Binder Renders

    Directory of Open Access Journals (Sweden)

    Carmen DICO

    2013-07-01

    Full Text Available Year after year we witness the negative effect of water over buildings, caused by direct or indirect actions. This situation is obvious in case of old, historical building, subjected to this aggression for a long period of time, but new buildings are also affected. Moisture in building materials causes not only structural damage, but also reduces the thermal insulation capacity of building components.Materials like plasters or paints have been used historically for a long period of time, fulfilling two basics functions: Decoration and Protection. The most acute demands are made on exterior plasters, as they, besides being an important decorative element for the facade, must perform two different functions simultaneously: protect the substrate against weathering and moisture without sealing, providing it a certain ability to “breathe” (Heilen, 2005. In order to accomplish this aim, the first step is to understand the hygrothermal behavior of coating and substrate and define the fundamental principles of moisture transfer; According to Künzel’s Facade Protection Theory, two material properties play the most important role: Water absorption and Vapor permeability.In the context of recently adoption (2009 of the “harmonized” European standard EN 15824 – „Specifications for external renders and internal plasters based on organic binders”, this paper deals extensively with the interaction of the two mentioned above properties for the coating materials, covered by EN 15824.

  20. WikiPrints: rendering enterprise Wiki content for printing

    Science.gov (United States)

    Berkner, Kathrin

    2010-02-01

    Wikis have become a tool of choice for collaborative, informative communication. In contrast to the immense Wikipedia, that serves as a reference web site and typically covers only one topic per web page, enterprise wikis are often used as project management tools and contain several closely related pages authored by members of one project. In that scenario it is useful to print closely related content for review or teaching purposes. In this paper we propose a novel technique for rendering enterprise wiki content for printing called WikiPrints, that creates a linearized version of wiki content formatted as a mixture between web layout and conventional document layout suitable for printing. Compared to existing print options for wiki content, Wikiprints automatically selects content from different wiki pages given user preferences and usage scenarios. Meta data such as content authors or time of content editing are considered. A preview of the linearized content is shown to the user and an interface for making manual formatting changes provided.

  1. Differentiation renders susceptibility to excitotoxicity in HT22 neurons

    Institute of Scientific and Technical Information of China (English)

    Minchao He; Jun Liu; Shaowu Cheng; Yigang Xing; William Z Suo

    2013-01-01

    HT22 is an immortalized mouse hippocampal neuronal cell line that does not express cholinergic and glutamate receptors like mature hippocampal neurons in vivo. This in part prevents its use as a model for mature hippocampal neurons in memory-related studies. We now report that HT22 cells were appropriately induced to differentiate and possess properties similar to those of mature hippocampal neurons in vivo, such as becoming more glutamate-receptive and excitatory. Results showed that sensitivity of HT22 cells to glutamate-induced toxicity changed dramatically when comparing undifferentiated with differentiated cells, with the half-effective concentration for differentiated cells reducing approximately two orders of magnitude. Moreover, glutamate-induced toxicity in differentiated cells, but not undifferentiated cells, was inhibited by the N-methyl-D- aspartate receptor antagonists MK-801 and memantine. Evidently, differentiated HT22 cells expressed N-methyl-D-aspartate receptors, while undifferentiated cells did not. Our experimental findings indicated that differentiation is important for immortalized cell lines to render post-mitotic neuronal properties, and that differentiated HT22 neurons represent a better model of hippocampal neurons than undifferentiated cells.

  2. The summer school students’ viewpoints about important factors in learning, Shiraz University of Medical Sciences

    Directory of Open Access Journals (Sweden)

    LEILA BAZRAFCAN

    2014-04-01

    Full Text Available Introduction: The main goal of education is learning and change in behavior which has been revolutionized in the 21st century due to the rapid and widespread changes in science. The traditional approach to education does no longer meet the learners’ needs, necessitating new changes in educational curricula. This study was designed to determine the factors influencing learning in the 21st century and find out the students’ viewpoints on this issue. Methods: This is a descriptive study aiming at determining the students’ views on new approaches to learning in the 21st century. To do so, a researcher-made questionnaire was designed. It contained 30 questions in 3 sections including demographic data, background questions and two open questions about their suggestions and criticisms. The reliability and validity of the questionnaire was pilot-tested and measured, which proved to be describable. 150 students participating in university summer schools in Shiraz University of Medical Sciences were enrolled. The questionnaires were sent to the students in person and through electronic mails. The students were asked to return the completed questionnaires to the given email address. The data were analyzed in SPSS, version 14, using descriptive statistics of frequency, mean, percentage and standard deviation and t-test. P<0. 05 was considered as statistically significant. Results: 150 questionnaires were appropriately filled out and given to the researchers. The results indicated that, according to the students, 6 factors including the use of computer in teaching, enhancement of virtual learning, the use of mobile in relations, enjoyment of electronic learning contexts, the learning focus on attitudes and the facilitating role of the lectures were the most influential factors in learning. On the other hand, the government’s responsibility and responsiveness, creativity and risk taking, increase in the social relationship among the learners, focus on

  3. Virtual World Security Inspection

    Directory of Open Access Journals (Sweden)

    Nicholas Charles Patterson

    2012-06-01

    Full Text Available Virtual property theft is a serious problem that exists in virtual worlds. Legitimate users of these worlds invest considerable amounts of time, effort and real-world money into obtaining virtual property, but unfortunately, are becoming victims of theft in high numbers. It is reported that there are over 1 billion registered users of virtual worlds containing virtual property items worth an estimated US$50 billion dollars. The problem of virtual property theft is complex, involving many legal, social and technological issues. The software used to access virtual worlds is of great importance as they form the primary interface to these worlds and as such the primary interface to conduct virtual property theft. The security vulnerabilities of virtual world applications have not, to date, been examined. This study aims to use the process of software inspection to discover security vulnerabilities that may exist within virtual world software – vulnerabilities that enable virtual property theft to occur. Analyzing three well know virtual world applications World of Warcraft, Guild Wars and Entropia Universe, this research utilized security analysis tools and scenario testing with focus on authentication, trading, intruder detection and virtual property recovery. It was discovered that all three examples were susceptible to keylogging, mail and direct trade methods were the most likely method for transferring stolen items, intrusion detection is of critical concern to all VWEs tested, stolen items were unable to be recovered in all cases and lastly occurrences of theft were undetectable in all cases. The results gained in this study present the key problem areas which need to be addressed to improve security and reduce the occurrence of virtual property theft.

  4. Design and Implementation of an Application. Programming Interface for Volume Rendering

    OpenAIRE

    Selldin, Håkan

    2002-01-01

    To efficiently examine volumetric data sets from CT or MRI scans good volume rendering applications are needed. This thesis describes the design and implementation of an application programming interface (API) to be used when developing volume-rendering applications. A complete application programming interface has been designed. The interface is designed so that it makes writing application programs containing volume rendering fast and easy. The interface also makes created application progr...

  5. Dimension of spacetime from the viewpoint of different fields

    CERN Document Server

    Kaviani, K

    2014-01-01

    In this paper a new geometric perspective on gravity is considered, proposing a different geometric feature of gravitational effects on Minkowski spacetime which can be seen as classification of the spacetime into some equivalence classes. By introducing some geometric objects based on noncommutative geometry, one can switch between field-picture and geometry-picture representing gravity and conclude dimensionally dependence of gravitational field equation and consequently emerging different features of gravity in spacetimes with different dimensions. Furthermore in the case of interaction of gravity with an external field, one can deduce that from the viewpoint of different fields, spacetime can be seen as an object with different dimensions. The proposal makes the possibility of resolving blackhole singularity and also observing some similarities with Kaluza-Klein-like theories where a reduction from higher to lower dimensional gravity is associated with emerging some different fields.

  6. Chinese Culture of Learning from Western Teachers’Viewpoint

    Institute of Scientific and Technical Information of China (English)

    邹旭

    2014-01-01

    While more and more teachers from Western culture teach in China, research on the different cultures of learning in China's teaching context and Western teachers’views on the Chinese culture of learning and teaching have been rarely conduct-ed. This essay discusses the implications of cultural differences of learning between China and the West, particularly Western teachers’viewpoint on Chinese culture of learning. The conclusion suggests that it is of great importance to be aware that culture is just one of many factors that determine individual learning, and teachers are supposed to avoid stereotyping and simplistic views with regard to culture of learning, though general trends and patterns may exist among a certain type of culture.

  7. Virtual Campus in the Context of an Educational Virtual City

    Science.gov (United States)

    Fominykh, Mikhail; Prasolova-Forland, Ekaterina; Morozov, Mikhail; Gerasimov, Alexey

    2011-01-01

    This paper is focused on virtual campuses, i.e. virtual worlds representing real educational institutions that are based on the metaphor of a university and provide users with different learning tools. More specifically, the idea of integrating a virtual campus into the context of a virtual city is suggested. Such a virtual city, where students…

  8. Influence of rendering methods on yield and quality of chicken fat recovered from broiler skin

    Directory of Open Access Journals (Sweden)

    Liang-Kun Lin

    2017-06-01

    Full Text Available Objective In order to utilize fat from broiler byproducts efficiently, it is necessary to develop an appropriate rendering procedure and establish quality information for the rendered fat. A study was therefore undertaken to evaluate the influence of rendering methods on the amounts and general properties of the fat recovered from broiler skin. Methods The yield and quality of the broiler skin fat rendered through high and lower energy microwave rendering (3.6 W/g for 10 min and 2.4 W/g for 10 min for high power microwave rendering (HPMR and high power microwave rendering (LPMR, respectively, oven baking (OB, at 180°C for 40 min, and water cooking (WC, boiling for 40 min were compared. Results Microwave-rendered skin exhibited the highest yields and fat recovery rates, followed by OB, and WC fats (p<0.05. HPMR fat had the highest L*, a*, and b* values, whereas WC fat had the highest moisture content, acid values, and thiobarbituric acid (TBA values (p<0.05. There was no significant difference in the acid value, peroxide value, and TBA values between HPMR and LPMR fats. Conclusion Microwave rendering at a power level of 3.6 W/g for 10 min is suggested base on the yield and quality of chicken fat.

  9. Real-time volume rendering of digital medical images on an iOS device

    Science.gov (United States)

    Noon, Christian; Holub, Joseph; Winer, Eliot

    2013-03-01

    Performing high quality 3D visualizations on mobile devices, while tantalizingly close in many areas, is still a quite difficult task. This is especially true for 3D volume rendering of digital medical images. Allowing this would empower medical personnel a powerful tool to diagnose and treat patients and train the next generation of physicians. This research focuses on performing real time volume rendering of digital medical images on iOS devices using custom developed GPU shaders for orthogonal texture slicing. An interactive volume renderer was designed and developed with several new features including dynamic modification of render resolutions, an incremental render loop, a shader-based clipping algorithm to support OpenGL ES 2.0, and an internal backface culling algorithm for properly sorting rendered geometry with alpha blending. The application was developed using several application programming interfaces (APIs) such as OpenSceneGraph (OSG) as the primary graphics renderer coupled with iOS Cocoa Touch for user interaction, and DCMTK for DICOM I/O. The developed application rendered volume datasets over 450 slices up to 50-60 frames per second, depending on the specific model of the iOS device. All rendering is done locally on the device so no Internet connection is required.

  10. Interactive Ray Tracing for Virtual TV Studio Applications

    Directory of Open Access Journals (Sweden)

    Philipp Slusallek

    2005-12-01

    Full Text Available In the last years, the well known ray tracing algorithm gained new popularity with the introduction of interactive ray tracing methods. The high modularity and the ability to produce highly realistic images make ray tracing an attractive alternative to raster graphics hardware.Interactive ray tracing also proved its potential in the field of Mixed Reality rendering and provides novel methods for seamless integration of real and virtual content. Actor insertion methods, a subdomain of Mixed Reality and closely related to virtual television studio techniques, can use ray tracing for achieving high output quality in conjunction with appropriate visual cues like shadows and reflections at interactive frame rates.In this paper, we show how interactive ray tracing techniques can provide new ways of implementing future virtual studio applications.

  11. Analysis of Reconfigured Control Loop with a Virtual Actuator

    Directory of Open Access Journals (Sweden)

    Anna Filasova

    2011-01-01

    Full Text Available Control reconfiguration changes the control structure in response to a fault detected in the plant. This becomes necessary, because a major fault like loss of an actuator breaks the corresponding control loop and therefore renders the whole system inoperable.  An important aim of control reconfiguration is to change the control structure as little as possible, since every change bears the potential of practical problems. The proposed solution is to keep the original controller in the loop and to add an extension called virtual actuator that implements the necessary changes of the control structure. The virtual actuator translates between the signals of the nominal controller and the signal of the faulty plants. This paper is concerned with the analysis of reconfigured loop with a virtual actuator for the system with the faulty actuator. The proposed analysis is illustrated on numerical example.

  12. Virtual CT laparoscopic imaging using intravenous cholangiography with helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Masafumi; Ishibashi, Masatoshi; Nishimura, Hiroshi; Hayabuchi, Naofumi [Kurume Univ., Fukuoka (Japan). School of Medicine

    2000-08-01

    Laparoscopic cholecystectomy is a reatively new technology that allows for minimally invasive treatment of cholelithiasis. The purpose of this paper is to demonstrate the feasibility of virtual laparoscopic imaging using helical CT cholangiography with volume rendering technique. We used the technique with ten patients with suspected gallbladder abnormalities. Our imaging sets produced high quality 3D images with excellent visualization in 70% (7/10) of all cases. Virtual laparoscopic imaging was also compared with other imaging techniques and imaging using helical scans can proved useful in preoperative imaging. Furthermore, virtual laparoscopic imaging using helical scans can in surgical planning and serve as a visual aid in discussions between radiologists, surgeons, and patients. (author)

  13. Virtual reality exposure therapy.

    Science.gov (United States)

    Rothbaum, B O; Hodges, L; Kooper, R

    1997-01-01

    It has been proposed that virtual reality (VR) exposure may be an alternative to standard in vivo exposure. Virtual reality integrates real-time computer graphics, body tracking devices, visual displays, and other sensory input devices to immerse a participant in a computer-generated virtual environment. Virtual reality exposure is potentially an efficient and cost-effective treatment of anxiety disorders. VR exposure therapy reduced the fear of heights in the first controlled study of virtual reality in treatment of a psychiatric disorder. A case study supported the efficacy of VR exposure therapy for the fear of flying. The potential for virtual reality exposure treatment for these and other disorders is explored, and therapeutic issues surrounding the delivery of VR exposure are discussed.

  14. Transforming Virtual Teams

    DEFF Research Database (Denmark)

    Bjørn, Pernille

    2005-01-01

    Investigating virtual team collaboration in industry using grounded theory this paper presents the in-dept analysis of empirical work conducted in a global organization of 100.000 employees where a global virtual team with participants from Sweden, United Kingdom, Canada, and North America were...... studied. The research question investigated is how collaboration is negotiated within virtual teams? This paper presents findings concerning how collaboration is negotiated within a virtual team and elaborate the difficulties due to invisible articulation work and managing multiple communities...... in transforming the virtual team into a community. It is argued that translucence in communication structures within the virtual team and between team and management is essential for engaging in a positive transformation process of trustworthiness supporting the team becoming a community, managing the immanent...

  15. Virtual reality for engineering

    CERN Document Server

    De Gennaro, Silvano; CERN. Geneva

    1996-01-01

    Virtual Reality for Engineers. Virtual Reality is a very powerful visualization technique for 3D data, which can bring enormous benefits to engineering design. CAD models can be exported to a VR application and used as "Virtual Prototypes". Virtual Prototypes are an ideal replacement for wooden models as they can be generated automatically from most CAD products. They are totally reliable, they can be updated in a matter of minutes, and they allow designers to explore them from inside, on a one-to-one scale and using a 3D-stereo vision. Navigation can be performed using a number of instinctive tools, such as joysticks, spaceballs, VR helmets and 3D mice. The lectures will cover today's Virtual Reality products and methods, and describe how to transform CAD models into Virtual Prototypes. A "hands on" VR experience featuring the LHC detectors models can be organized for people interested.

  16. Trust and virtual worlds

    DEFF Research Database (Denmark)

    Ess, Charles; Thorseth, May

    2011-01-01

    by virtuality, such as virtual child pornography. The introduction further develops a philosophical anthropology, rooted in Kantian ethics, phenomenology, virtue ethics, and feminist perspectives, that grounds a specific approach to ethical issues in virtual environments....... of embodiment in establishing trust in (primarily) disembodied venues; how far artificial agents and other forms of machine intelligence can be trusted in any strong sense; and how diverse ethical frameworks, as developed in embodied contexts and histories, may (not) be applied to ethical issues evoked...

  17. Framing Virtual Law

    OpenAIRE

    Edelmann, Peter

    2005-01-01

    This paper proposes a framework for understanding the real-virtual dichotomy in terms of a series of five frames or layers which interact simultaneously to create the phenomena associated with virtual worlds. The framework presented in this paper is intended to be used as an analytical tool in studying phenomena related specifically to virtual worlds, but is undoubtedly applicable to a broad subset of computer games and interactive fiction. The model provides a useful tool fpr studying a numb...

  18. Virtual Campus Hub technology

    DEFF Research Database (Denmark)

    Vercoulen, Frank; Badger, Merete; Monaco, Lucio;

    This deliverable briefly describes which technological components have been delivered for the Virtual Campus Hub and how they can be used. A detailed discussion of the technical details of the components, how they were realized and how they fit the VCH concept can be found in deliverables D5.......4. Virtual Campus Hub Technology Evaluation Report and D6.7 The Virtual Campus Hub Concept....

  19. Managing global virtual teams

    OpenAIRE

    Saarinen, Johanna

    2016-01-01

    Advances in technology-enabled communication and a constant search for economic advantage have led global organizations to rely on virtual collaboration. Together with rapid changes in working life, virtuality has also altered the context for leadership and has had a significant impact on the work of managers. This study addresses managerial work in global virtual teams. In my study, I give voice to the managers themselves with the aim of enhancing our understanding of what the work of virtua...

  20. Wireless Virtual Joystick

    OpenAIRE

    Hu, Yuning

    2013-01-01

    Wireless Virtual Joystick is an Android application which enables users to use their Android mobile device act like a real joystick. It provides a solution to establish a wireless connection between Android mobile device and server computer. Whenever the server receives correct message, the server will simulate a virtual joystick input signal. Wireless Virtual Joystick does not worry about the small space, wires jam or USB port limitation. The objective of this thesis project is to develop a ...

  1. Virtual currencies : Real opportunities?

    OpenAIRE

    Selldahl, Sara

    2013-01-01

    AbstractThe European Central Bank defines virtual currencies as ”unregulated, digital money, which is issued and usuallycontrolled by its developers, and used and accepted among the members of a specific virtual community.”(European Central Bank, 2012, p. 5) The interest in virtual currencies has increased immensely over the last fewyears as they become increasingly prevalent in our society across many different industries. Up until now, the field ofvirtual currencies has been mainly uncharte...

  2. Hierarchical rendering of trees from precomputed multi-layer z-buffers

    Energy Technology Data Exchange (ETDEWEB)

    Max, N. [California Univ., Davis, CA (United States)

    1996-02-01

    Chen and Williams show how precomputed z-buffer images from different fixed viewing positions can be reprojected to produce an image for a new viewpoint. Here images are precomputed for twigs and branches at various levels in the hierarchical structure of a tree, and adaptively combined, depending on the position of the new viewpoint. The precomputed images contain multiple z levels to avoid missing pixels in the reconstruction, subpixel masks for anti-aliasing, and colors and normals for shading after reprojection.

  3. Virtual articulators in prosthodontics

    National Research Council Canada - National Science Library

    R.S., Gugwad; M., Basavakumar; K., Abhijeet; M., Arvind; M., Sudhindra; C., Ramesh

    2011-01-01

    Virtual technologies in dentistry provide better education and training by simulating complex contexts and enhancing procedures that are traditionally limited, such as work with mechanical articulator...

  4. Debugging the virtual machine

    Energy Technology Data Exchange (ETDEWEB)

    Miller, P.; Pizzi, R.

    1994-09-02

    A computer program is really nothing more than a virtual machine built to perform a task. The program`s source code expresses abstract constructs using low level language features. When a virtual machine breaks, it can be very difficult to debug because typical debuggers provide only low level machine implementation in formation to the software engineer. We believe that the debugging task can be simplified by introducing aspects of the abstract design into the source code. We introduce OODIE, an object-oriented language extension that allows programmers to specify a virtual debugging environment which includes the design and abstract data types of the virtual machine.

  5. Spacebody actual virtual

    DEFF Research Database (Denmark)

    Kjøbek, Jytte; Sørensen, Gert

    2005-01-01

    DVD som indeholder filmen 'spacebody actual virtual' . Videoen er værkdelen af forskningsprojektet Arkitektur og skikkelse, spacebody actual virtual. Foruden DVD'en indeholder projektet et reflekterende materiale på hjemmesiden www.spacebody.dk Fysisk medie: DVD......DVD som indeholder filmen 'spacebody actual virtual' . Videoen er værkdelen af forskningsprojektet Arkitektur og skikkelse, spacebody actual virtual. Foruden DVD'en indeholder projektet et reflekterende materiale på hjemmesiden www.spacebody.dk Fysisk medie: DVD...

  6. Learning by doing virtually.

    Science.gov (United States)

    von Sternberg, N; Bartsch, M S; Petersik, A; Wiltfang, J; Sibbersen, W; Grindel, T; Tiede, U; Warnke, P H; Heiland, M; Russo, P A J; Terheyden, H; Pohlenz, P; Springer, I N

    2007-05-01

    Selective reduction of bone without collateral damage (nerves, teeth) is essential in apicectomy. To test whether skills acquired on a virtual apicectomy simulator (VOXEL-MAN system with integrated force-feedback) are transferable from virtual to physical reality, two groups of trainees were compared. Group 1 received computer-based virtual surgical training before performing an apicectomy in a pig cadaver model. The probability of preserving vital neighboring structures was improved significantly, i.e. six-fold, after virtual surgical training (Papicectomy simulator appears to be effective, and the skills acquired are transferable to physical reality.

  7. Virtual Machine Introspection

    Directory of Open Access Journals (Sweden)

    S C Rachana

    2014-06-01

    Full Text Available Cloud computing is an Internet-based computing solution which provides the resources in an effective manner. A very serious issue in cloud computing is security which is a major obstacle for the adoption of cloud. The most important threats of cloud computing are Multitenancy, Availability, Loss of control, Loss of Data, outside attacks, DOS attacks, malicious insiders, etc. Among many security issues in cloud, the Virtual Machine Security is one of the very serious issues. Thus, monitoring of virtual machine is essential. The paper proposes a Virtual Network Introspection [VMI] System to secure the Virtual machines from Distributed Denial of Service [DDOS] and Zombie attacks.

  8. Virtual Machine Introspection

    Directory of Open Access Journals (Sweden)

    S C Rachana

    2015-11-01

    Full Text Available Cloud computing is an Internet-based computing solution which provides the resources in an effective manner. A very serious issue in cloud computing is security which is a major obstacle for the adoption of cloud. The most important threats of cloud computing are Multitenancy, Availability, Loss of control, Loss of Data, outside attacks, DOS attacks, malicious insiders, etc. Among many security issues in cloud, the Virtual Machine Security is one of the very serious issues. Thus, monitoring of virtual machine is essential. The paper proposes a Virtual Network Introspection [VMI] System to secure the Virtual machines from Distributed Denial of Service [DDOS] and Zombie attacks.

  9. Virtual Reality Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Performs basic and applied research in interactive 3D computer graphics, including visual analytics, virtual environments, and augmented reality (AR). The...

  10. Virtual Training Devices Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Virtual Training Devices (VTD) Laboratory at the Life Cycle Software Engineering Center, Picatinny Arsenal, provides a software testing and support environment...

  11. Face recognition is similarly affected by viewpoint in school-aged children and adults

    Directory of Open Access Journals (Sweden)

    Marisa Nordt

    2017-05-01

    Full Text Available There is an ongoing debate on the question when face processing abilities mature. One aspect that has been part of this debate is the ability to recognize faces in and across different viewpoints. Here, we tested 128 participants consisting of school-age children (ages, 5–10 years and adults (ages, 19–37 years in two experiments to investigate the effects of different viewpoints (including front, three-quarter, profile view on face recognition during development. Furthermore, we compared recognition performance for faces to that of another object category (cars. In the first experiment (n = 88 we tested if the pattern of performance for faces presented in different viewpoints is similar in school-aged children and adults. Participants completed a two-alternative-forced-choice (2AFC memory task comprising images of both faces and cars in front, three-quarter and profile view, which were presented in the same viewpoint during learning and testing. In the second experiment (n = 40 we tested if face recognition is similarly affected by viewpoint changes in children and adults. In this experiment the 2AFC memory task included a change of viewpoint between learning and testing. While in both experiments we found higher recognition performance for faces with increasing age, the overall pattern of both viewpoint and viewpoint-change-effects and also the difference between view-change- and no-change-conditions was similar across age groups. In contrast to faces, no viewpoint effects were observed in cars (experiment 1, viewpoint change effects, however, were similar for cars and faces (experiment 2. In sum, our results suggest early maturity of the ability to recognize faces in and across different viewpoints.

  12. VIRTUAL FUEL-PUMP DESIGN

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Some concepts of virtual product are discussed. The key technologies of virtual fuel-pump development are in detail analysed, which include virtual fuel-pump product modeling, intelligent simulation, distributed design environment, and virtual assembly. The virtual fuel-pump development prototype system considers requirement analysis, concept design, injection preferment analysis, detailed design, and assembly analysis.

  13. Should laptops be allowed in the classroom? Two viewpoints: viewpoint 1: laptops in classrooms facilitate curricular advancement and promote student learning and viewpoint 2: deconstructing and rethinking the use of laptops in the classroom.

    Science.gov (United States)

    Spallek, Heiko; von Bergmann, HsingChi

    2014-12-01

    This Point/Counterpoint article discusses the pros and cons of deploying one aspect of instructional technology in dental education: the use of laptops in the classroom. Two opposing viewpoints, written by different authors, evaluate the arguments. Viewpoint 1 argues that laptops in classrooms can be a catalyst for rapid curricular advancement and prepare dental graduates for the digital age of dentistry. As dental education is not limited to textual information, but includes skill development in spatial relationships and hands-on training, technology can play a transformative role in students' learning. Carefully implemented instructional technology can enhance student motivation when it transforms students from being the objects of teaching to the subjects of learning. Ubiquitous access to educational material allows for just-in-time learning and can overcome organizational barriers when, for instance, introducing interprofessional education. Viewpoint 2 argues that, in spite of widespread agreement that instructional technology leads to curricular innovation, the notion of the use of laptops in classrooms needs to be deconstructed and rethought when effective learning outcomes are sought. Analyzing the purpose, pedagogy, and learning product while applying lessons learned from K-12 implementation leads to a more complex picture of laptop integration in dental classrooms and forms the basis for questioning the value of such usage. For laptop use to contribute to student learning, rather than simply providing opportunity for students to take notes and access the Internet during class, this viewpoint emphasizes that dental educators need to think carefully about the purpose of this technology and to develop appropriate pedagogical strategies to achieve their objectives. The two viewpoints agree that significant faculty development efforts should precede any introduction of technology into the educational process and that technology alone cannot change education

  14. 基于摩擦力控制的触觉再现系统研究%Research on Tactile Rendering System Based on Friction Control

    Institute of Scientific and Technical Information of China (English)

    马露; 陆熊

    2015-01-01

    作为新兴的人机交互技术,触觉再现技术能够再现虚拟物体的表面特性,提高虚拟现实系统的真实性。在目前现有的触觉再现技术中,基于摩擦力控制的触觉再现技术能够实现连续的、精细的纹理触觉再现,已成为触觉再现领域的一个研究热点。因此,设计一套基于摩擦力控制的触觉再现系统就显得尤为重要。基于此,文中利用空气压膜效应原理,设计了一套基于摩擦力控制的触觉再现系统,该系统能够实现虚拟纹理的触觉输出。文中首先描述了空气压膜效应的产生机理,然后详细讲述了该触觉再现系统的整体构成,最后,通过一系列的触觉感知实验验证了该系统的有效性。%As a novel human-computer interaction technology,tactile rendering can express the surface characteristics of virtual objects, and enhance the realism of virtual reality systems. Among several tactile rendering technologies,friction control based technology can real-ize continuous and fine tactile perception,and has become a hot research in tactile rendering filed. Therefore,designing a tactile rendering system,which based on the friction control,is particularly important. Based on this,present a tactile rendering device in this paper based on friction control,by using the principle of squeeze film effect. Firstly,describe the mechanism of squeeze film effect. Then,demonstrate the whole structure of this system and several experiments are made to validate the effectiveness of this system at last.

  15. 31 CFR 515.548 - Services rendered by Cuba to United States aircraft.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Services rendered by Cuba to United... REGULATIONS Licenses, Authorizations, and Statements of Licensing Policy § 515.548 Services rendered by Cuba to United States aircraft. Specific licenses are issued for payment to Cuba of charges for services...

  16. Frequency domain volume rendering by the wavelet X-ray transform

    NARCIS (Netherlands)

    Westenberg, Michel A.; Roerdink, Jos B.T.M.

    2000-01-01

    We describe a wavelet-based X-ray rendering method in the frequency domain with a smaller time complexity than wavelet splatting. Standard Fourier volume rendering is summarized and interpolation and accuracy issues are briefly discussed. We review the implementation of the fast wavelet transform in

  17. Evaluation of voxel-based rendering of high resolution surface descriptions

    DEFF Research Database (Denmark)

    Hammershøi, Dorte; Olesen, Søren Krarup; Markovic, Milos

    2014-01-01

    responses by having more “distinct” representations of the individual reflections. When rendered audible, such descriptions will lead to a sound quality that can best be described as “canned”. For the rendering of real rooms, as e.g. in "teletransporting", this problem may be addressed by using high...

  18. Virtual Entity-Based Rapid Prototype for Design and Simulation of Humanoid Robots

    Directory of Open Access Journals (Sweden)

    Guofeng Tong

    2013-07-01

    Full Text Available This paper proposes a framework for a virtual entity‐based rapid prototype (VERP to facilitate the design and simulation of humanoid robots. The VERP framework consists of three components: virtual entities, a high‐fidelity simulation environment with physical and rendering engines, and an interface between the physical and simulation environments. To study the effectiveness of the proposed framework, we present a complete prototype for a humanoid robot using virtual entity modelling, control algorithm design and simulation. The humanoid robot is mathematically modelled with adjustable physical parameters which determine the kinematic and dynamic behaviour of the virtual entity in the simulation environment. With the simulated model, a control scheme for the virtual entity and the actual humanoid robot are designed and implemented through the interface. The empirical experiments and numerical analysis show the effectiveness and preciseness of the proposed VERP in terms of simulation fidelity, dynamic performance, and control interface.

  19. Method for Correcting Control Surface Angle Measurements in Single Viewpoint Photogrammetry

    Science.gov (United States)

    Burner, Alpheus W. (Inventor); Barrows, Danny A. (Inventor)

    2006-01-01

    A method of determining a corrected control surface angle for use in single viewpoint photogrammetry to correct control surface angle measurements affected by wing bending. First and second visual targets are spaced apart &om one another on a control surface of an aircraft wing. The targets are positioned at a semispan distance along the aircraft wing. A reference target separation distance is determined using single viewpoint photogrammetry for a "wind off condition. An apparent target separation distance is then computed for "wind on." The difference between the reference and apparent target separation distances is minimized by recomputing the single viewpoint photogrammetric solution for incrementally changed values of target semispan distances. A final single viewpoint photogrammetric solution is then generated that uses the corrected semispan distance that produced the minimized difference between the reference and apparent target separation distances. The final single viewpoint photogrammetric solution set is used to determine the corrected control surface angle.

  20. Taxation of virtual currency

    NARCIS (Netherlands)

    Bal, Aleksandra Marta

    2014-01-01

    The Information Age has created a new concept of money – virtual currencies existing solely in the cyberspace in the form of intangible computer code. The most prominent virtual currency scheme, Bitcoin, grabbed the public attention as its value skyrocketed at the beginning of 2012. Whereas Bitcoin

  1. OVERLAPPING VIRTUAL CADASTRAL DOCUMENTATION

    Directory of Open Access Journals (Sweden)

    Madalina - Cristina Marian

    2013-12-01

    Full Text Available Two cadastrale plans of buildings, can overlap virtual. Overlap is highlighted when digital reception. According to Law no. 7/1996 as amended and supplemented, to solve these problems is by updating the database graphs, the repositioning. This paper addresses the issue of overlapping virtual cadastre in the history of the period 1999-2012.

  2. Virtual Reality in Psychology

    Science.gov (United States)

    Foreman, Nigel

    2009-01-01

    The benefits of using virtual environments (VEs) in psychology arise from the fact that movements in virtual space, and accompanying perceptual changes, are treated by the brain in much the same way as those in equivalent real space. The research benefits of using VEs, in areas of psychology such as spatial learning and cognition, include…

  3. VEM: Virtual Enterprise Methodology

    DEFF Research Database (Denmark)

    Tølle, Martin; Vesterager, Johan

    2003-01-01

    This chapter presents a virtual enterprise methodology (VEM) that outlines activities to consider when setting up and managing virtual enterprises (VEs). As a methodology the VEM helps companies to ask the right questions when preparing for and setting up an enterprise network, which works...

  4. Taxation of virtual currency

    NARCIS (Netherlands)

    Bal, Aleksandra Marta

    2014-01-01

    The Information Age has created a new concept of money – virtual currencies existing solely in the cyberspace in the form of intangible computer code. The most prominent virtual currency scheme, Bitcoin, grabbed the public attention as its value skyrocketed at the beginning of 2012. Whereas Bitcoin

  5. Virtual Seminar Room

    DEFF Research Database (Denmark)

    Forchhammer, Søren Otto; Fosgerau, Anders; Hansen, Peter Søren Kirk

    1999-01-01

    The initial design considerations and research goals for an ATM network based virtual seminar room with 5 sites are presented.......The initial design considerations and research goals for an ATM network based virtual seminar room with 5 sites are presented....

  6. Virtual Company and Modelbank

    DEFF Research Database (Denmark)

    Thorsteinsson, Uffe

    1996-01-01

    Ansøgning til Socrates programmet vedr. Tematisk netværk inden for området Virtual Company and Modelbank......Ansøgning til Socrates programmet vedr. Tematisk netværk inden for området Virtual Company and Modelbank...

  7. Designing Virtual Learning Environments

    DEFF Research Database (Denmark)

    Veirum, Niels Einar

    2003-01-01

    The main objective of this working paper is to present a conceptual model for media integrated communication in virtual learning environments. The model for media integrated communication is very simple and identifies the necessary building blocks for virtual place making in a synthesis of methods...

  8. Virtual Reality Disruption

    National Research Council Canada - National Science Library

    Michael B Horn

    2016-01-01

    ... speculation about virtual reality's readiness to break through to the educational mainstream. The question is whether we should believe the hype. More Broadband, More Investment First, schools are upgrading their Internet connectivity, which is setting the stage for broadband-dependent virtual-reality learning. The federal ConnectED i...

  9. Virtual Trackballs Revisited

    DEFF Research Database (Denmark)

    Henriksen, Knud; Sporring, Jon; Hornbæk, Kasper

    2004-01-01

    Rotation of three-dimensional objects by a two-dimensional mouse is a typical task in computer-aided design, operation simulations, and desktop virtual reality. The most commonly used rotation technique is a virtual trackball surrounding the object and operated by the mouse pointer. This article...

  10. Virtual School Counseling

    Science.gov (United States)

    Osborn, Debra S.; Peterson, Gary W.; Hale, Rebecca R.

    2015-01-01

    The advent of virtual schools opens doors to opportunity for delivery of student services via the Internet. Through the use of structured interviews with four practicing Florida virtual school counselors, and a follow-up survey, the authors examined the experiences and reflections of school counselors who are employed full time in a statewide…

  11. Virtual School Counseling

    Science.gov (United States)

    Osborn, Debra S.; Peterson, Gary W.; Hale, Rebecca R.

    2015-01-01

    The advent of virtual schools opens doors to opportunity for delivery of student services via the Internet. Through the use of structured interviews with four practicing Florida virtual school counselors, and a follow-up survey, the authors examined the experiences and reflections of school counselors who are employed full time in a statewide…

  12. Virtual Auditory Displays

    Science.gov (United States)

    2000-01-01

    timbre , intensity, distance, room modeling, radio communication Virtual Environments Handbook Chapter 4 Virtual Auditory Displays Russell D... musical note “A” as a pure sinusoid, there will be 440 condensations and rarefactions per second. The distance between two adjacent condensations or...and complexity are pitch, loudness, and timbre respectively. This distinction between physical and perceptual measures of sound properties is an

  13. Virtual Trauma Team

    NARCIS (Netherlands)

    Jones, Valerie M.; Bults, Richard G.A.

    2001-01-01

    The clinical motivation for Virtual Trauma Team is to improve quality of care in trauma care in the vital first "golden hour" where correct intervention can greatly improve likely health outcome. The motivation for Virtual Homecare Team is to improve quality of life and independence for patients by

  14. VEM: Virtual Enterprise Methodology

    DEFF Research Database (Denmark)

    Tølle, Martin; Vesterager, Johan

    2003-01-01

    This chapter presents a virtual enterprise methodology (VEM) that outlines activities to consider when setting up and managing virtual enterprises (VEs). As a methodology the VEM helps companies to ask the right questions when preparing for and setting up an enterprise network, which works as a b...

  15. Digging the Virtual Past

    Science.gov (United States)

    Polymeropoulou, Panagiota

    2014-01-01

    In this paper we will investigate the way that the technological progress and the Informatics contributed greatly to the field of Archaeology. There will be analyzed the terms of virtual archaeology and virtual reality in archaeology and there will be an extended reference to the applications and the computer graphics that archaeologists could use…

  16. Virtual reality musical instruments

    DEFF Research Database (Denmark)

    Serafin, Stefania; Erkut, Cumhur; Kojs, Juraj

    2016-01-01

    The rapid development and availability of low cost technologies has created a wide interest in virtual reality (VR), but how to design and evaluate multisensory interactions in VR remains as a challenge. In this paper, we focus on virtual reality musical instruments, present an overview of our...

  17. Virtual Schools. Literature Review

    Science.gov (United States)

    Blazer, Christie

    2009-01-01

    The majority of school districts in the U.S. are providing some form of online learning for their students. In the past, virtual schools primarily targeted advanced students who didn't have access to certain courses in their regular schools. Recently, however, many virtual schools have shifted their focus to credit recovery as a way to provide…

  18. Designing Virtual Learning Environments

    DEFF Research Database (Denmark)

    Veirum, Niels Einar

    2003-01-01

    The main objective of this working paper is to present a conceptual model for media integrated communication in virtual learning environments. The model for media integrated communication is very simple and identifies the necessary building blocks for virtual place making in a synthesis of methods...... from Cultural Media Science, Architecture and Digital Design...

  19. Method and system for rendering and interacting with an adaptable computing environment

    Science.gov (United States)

    Osbourn, Gordon Cecil [Albuquerque, NM; Bouchard, Ann Marie [Albuquerque, NM

    2012-06-12

    An adaptable computing environment is implemented with software entities termed "s-machines", which self-assemble into hierarchical data structures capable of rendering and interacting with the computing environment. A hierarchical data structure includes a first hierarchical s-machine bound to a second hierarchical s-machine. The first hierarchical s-machine is associated with a first layer of a rendering region on a display screen and the second hierarchical s-machine is associated with a second layer of the rendering region overlaying at least a portion of the first layer. A screen element s-machine is linked to the first hierarchical s-machine. The screen element s-machine manages data associated with a screen element rendered to the display screen within the rendering region at the first layer.

  20. Accelerating Time-Varying Hardware Volume Rendering Using TSP Trees and Color-Based Error Metrics

    Science.gov (United States)

    Ellsworth, David; Chiang, Ling-Jen; Shen, Han-Wei; Kwak, Dochan (Technical Monitor)

    2000-01-01

    This paper describes a new hardware volume rendering algorithm for time-varying data. The algorithm uses the Time-Space Partitioning (TSP) tree data structure to identify regions within the data that have spatial or temporal coherence. By using this coherence, the rendering algorithm can improve performance when the volume data is larger than the texture memory capacity by decreasing the amount of textures required. This coherence can also allow improved speed by appropriately rendering flat-shaded polygons instead of textured polygons, and by not rendering transparent regions. To reduce the polygonization overhead caused by the use of the hierarchical data structure, we introduce an optimization method using polygon templates. The paper also introduces new color-based error metrics, which more accurately identify coherent regions compared to the earlier scalar-based metrics. By showing experimental results from runs using different data sets and error metrics, we demonstrate that the new methods give substantial improvements in volume rendering performance.

  1. The issue of virtual teams

    OpenAIRE

    Fleiberková, Šárka

    2012-01-01

    The aim of this diploma thesis is the introduction of teamwork and virtual teams. The theoretical part of this work describes the birth of teamwork, its definition, properties, advantages and disadvantages. Next part of diploma thesis is dedicated to the virtual team. It describes the difference among virtual and traditional team, definition and characteristics of virtual team as well as tools that are used in virtual team. The second, practical, unit is focused on virtual teams at universiti...

  2. Designing Virtual Worlds

    DEFF Research Database (Denmark)

    Gürsimsek, Remzi Ates

    2014-01-01

    The online social platforms known as virtual worlds present their users various affordances for avatar based co-presence, social interaction and provide tools for collaborative content creation, including objects, textures and animations. The users of these worlds navigate their avatars as personal...... mediators in 3D virtual space to collaborate and co-design the digital content. These co-designers are also the residents of these worlds, as they socialize by building inworld friendships. This article presents a social semiotic analysis of the three-dimensional virtual places and artifacts in the virtual...... the audio-visual characteristics of designing in multi-user virtual environments generate experiential, interpersonal and textual meaning potentials....

  3. Intelligent virtual teacher

    Science.gov (United States)

    Takács, Ondřej; Kostolányová, Kateřina

    2016-06-01

    This paper describes the Virtual Teacher that uses a set of rules to automatically adapt the way of teaching. These rules compose of two parts: conditions on various students' properties or learning situation; conclusions that specify different adaptation parameters. The rules can be used for general adaptation of each subject or they can be specific to some subject. The rule based system of Virtual Teacher is dedicated to be used in pedagogical experiments in adaptive e-learning and is therefore designed for users without education in computer science. The Virtual Teacher was used in dissertation theses of two students, who executed two pedagogical experiments. This paper also describes the phase of simulating and modeling of the theoretically prepared adaptive process in the modeling tool, which has all the required parameters and has been created especially for the occasion. The experiments are being conducted on groups of virtual students and by using a virtual study material.

  4. Organization Virtual or Networked?

    Directory of Open Access Journals (Sweden)

    Rūta Tamošiūnaitė

    2013-08-01

    Full Text Available Purpose—to present distinction between “virtual organization” and “networked organization”; giving their definitions.Design/methodology/approach—review of previous researches, systemic analyses of their findings and synthesis of distinctive characteristics of ”virtual organization” and “networked organization.”Findings—the main result of the research is key diverse features separating ”virtual organization” and ”networked organization.” Definitions of “virtual organization” and “networked organization” are presented.Originality/Value—distinction between “virtual organization” and “networked organization” creates possibilities to use all advantages of those types of organizations and gives foundation for deeper researches in this field.Research type: general review.

  5. Organization Virtual or Networked?

    Directory of Open Access Journals (Sweden)

    Rūta Tamošiūnaitė

    2011-08-01

    Full Text Available Purpose—to present distinction between “virtual organization” and “networked organization”; giving their definitions.Design/methodology/approach—review of previous researches, systemic analyses of their findings and synthesis of distinctive characteristics of ”virtual organization” and “networked organization.”Findings—the main result of the research is key diverse features separating ”virtual organization” and ”networked organization.” Definitions of “virtual organization” and “networked organization” are presented.Originality/Value—distinction between “virtual organization” and “networked organization” creates possibilities to use all advantages of those types of organizations and gives foundation for deeper researches in this field.

  6. Realization of Reconfigurable Virtual Environments for Virtual Testing

    Institute of Scientific and Technical Information of China (English)

    Wen-Yan Wu; Zheng-Xu Zhao

    2005-01-01

    This paper presents the design and implementation of reconfigurable virtual environments (VEs) for virtual testing. It proposes a hybrid design approach that is derived from a so-called integration and composition of the reconfiguration strategy. The designing process has thus evolved from binding virtual objects using reconfiguration rules within the context of virtual testing scenarios. Therefore reconfigurable virtual environments are established with improved flexibility and scalability, tailored to a wide range of virtual testing applications. Those virtual environments integrate virtual testing scenarios, data acquisition, databases, rule mapping and application interfaces, which yield modular testing functions and an open-ended system architecture with a set of extensible interface tools to realize data exchange within reconfigurable VEs.This enables virtual testing scenarios to be reconfigured interactively based on real time data and communication between virtual environments and real environments. A virtual testing application has been implemented using reconfigurable VEs.

  7. Multi-core and Many-core Shared-memory Parallel Raycasting Volume Rendering Optimization and Tuning

    Energy Technology Data Exchange (ETDEWEB)

    Howison, Mark

    2012-01-31

    Given the computing industry trend of increasing processing capacity by adding more cores to a chip, the focus of this work is tuning the performance of a staple visualization algorithm, raycasting volume rendering, for shared-memory parallelism on multi-core CPUs and many-core GPUs. Our approach is to vary tunable algorithmic settings, along with known algorithmic optimizations and two different memory layouts, and measure performance in terms of absolute runtime and L2 memory cache misses. Our results indicate there is a wide variation in runtime performance on all platforms, as much as 254% for the tunable parameters we test on multi-core CPUs and 265% on many-core GPUs, and the optimal configurations vary across platforms, often in a non-obvious way. For example, our results indicate the optimal configurations on the GPU occur at a crossover point between those that maintain good cache utilization and those that saturate computational throughput. This result is likely to be extremely difficult to predict with an empirical performance model for this particular algorithm because it has an unstructured memory access pattern that varies locally for individual rays and globally for the selected viewpoint. Our results also show that optimal parameters on modern architectures are markedly different from those in previous studies run on older architectures. And, given the dramatic performance variation across platforms for both optimal algorithm settings and performance results, there is a clear benefit for production visualization and analysis codes to adopt a strategy for performance optimization through auto-tuning. These benefits will likely become more pronounced in the future as the number of cores per chip and the cost of moving data through the memory hierarchy both increase.

  8. Should Lecture Recordings Be Mandated in Dental Schools? Two Viewpoints: Viewpoint 1: Lecture Recordings Should Be Mandatory in U.S. Dental Schools and Viewpoint 2: Lecture Recordings Should Not Be Mandatory in U.S. Dental Schools.

    Science.gov (United States)

    Zandona, Andrea Ferreira; Kinney, Janet; Seong, WookJin; Kumar, Vandana; Bendayan, Alexander; Hewlett, Edmond

    2016-12-01

    Transcription or recording of lectures has been in use for many years, and with the availability of high-fidelity recording, the practice is now ubiquitous in higher education. Since technology has permeated education and today's tech-savvy students have expectations for on-demand learning, dental schools are motivated to record lectures, albeit with positive and negative implications. This Point/Counterpoint article addresses the question of whether lecture recording should be mandatory in U.S. dental schools. Viewpoint 1 supports the statement that lecture recording should be mandatory. Proponents of this viewpoint argue that the benefits-notably, student satisfaction and potential for improvement in student performance-outweigh concerns. Viewpoint 2 takes the opposite position, arguing that lecture recording decreases students' classroom attendance and adversely affects the morale of educators. Additional arguments against mandatory lecture recordings involve the expense of incorporating technology that requires ongoing support.

  9. Asset Management Based Distributed Generation Placement from Load Growth Viewpoint

    Directory of Open Access Journals (Sweden)

    majid ghani varzaneh

    2014-10-01

    Full Text Available In this paper, by presenting the asset management model, it is tried to investigate the importance of distributed generation (DG unit placement from radial distribution system reliability indices sensitivity viewpoint and then DG placement will be carried out. Asset management model is designed and explained to maximize the benefit of distribution companies for invested capital. As the value of distribution system reliability indices depend on customers load pattern, any change in customers load pattern causes changes in distribution system reliability indices. One of the factors that changes customers load pattern, is load growth. With considering that the system hardware characteristics are being constant, the values of reliability indices are also highly dependent on load distribution. Therefore, for assessing the current studies the level of validity and the adequacy of system in future, current load distribution and load growth in future should be studied. In this paper, with optimal placement of DG, it is tried to minimize the distribution system reliability indices sensitivity in accordance with load growth in different load patterns.

  10. Complementarity of Sources in Studying Adaptation: An Oral History Viewpoint

    Directory of Open Access Journals (Sweden)

    Tiiu Jaago

    2008-08-01

    Full Text Available The purpose of this article is to elucidate the complementary natureof two types of sources: First, an autobiographical narrative about the Soviet period written in 2005, 14 years after the period described. Second, a court file created by the representatives of Soviet authority from their point of view and containing material from the period 1945–1994. Both documents represent very different genres, are temporally different, have different purposes, and different viewpoints. Inspired by the work of Alessandro Portelli, particularly by his model of multilayered history-telling, the method of separating texts in three layers, institutional, communal, and personal, is used. The central question about the possibility of complementary treatment of diverse sources in oral history is posed against the background of researching adaptation to the Soviet regime. Asking a direct question will not offer the researcher very much information about actual adaptation or inadaptability because the respondents will be affected by their attitude towards, and the act of remembering, the Soviet regime. Therefore, in the present study the language of written texts is chosen for analysis pointing out that two contrary concepts characterise adaptation to Soviet authority: opposition that disputes the authority’s point of view, and the inability to phrase phenomena in the ‘non-Soviet language’. Additionally, the problem of individual agency in encountering the repressive ideological and societal system as expressed in the sources both diachronically and synchronically is discussed.

  11. Eurasian Union on the Viewpoint of China: Geopolitical Perspective

    Directory of Open Access Journals (Sweden)

    Guo Cheng

    2015-12-01

    Full Text Available This article is about geopolitical strategic analyze of Russian President Vladimir Putin’s “Eurasian Union” strategy from Chinese viewpoint. The article describes historical background of Eurasian Union, its geopolitical purposes, achievements and weakness, particularly from China's national strategic design and stance of Central Asia in Eurasian Continent. The geopolitical analysis of possibility for Sino-Russian Alliance and realistic difficulties of it are provided. Different point of Chinese experts on Russia-West relations are given. Some of them believe that he Warsaw Pact and the Cold War revival in the CIS, its purpose is to play as geopolitical blunders against the Western countries under the leadership of NATO, IMF and the United States. While others, take into consideration the US-Russian Strategic Arms Reduction Treaty, and Russia’s actively participation in the former Group of Eight, accession to WTO and other initiatives that indicates the current Moscow is not the Soviet Union, and does not exclude cooperation with existing international system dominated by the Western world. And finally, China's own Eurasian strategy design is represented, especially China’s foreign policy options on Central Asia as solutions to some current existing geopolitical differences between China and Russia’s own Eurasian Strategy in order to achieve mutual win-set goal.

  12. Intuitive Experiences from Sohrevardi’s Viewpoint

    Directory of Open Access Journals (Sweden)

    Reza Heydarinoori

    2012-04-01

    Full Text Available The truth of intuitive experiences and how to fulfill them are among the issues that all people, cultures and rituals have faced with and expressed views about. There are two major approaches the essence-oriented notion which has emphasized on the cohesion and commonality of these experiences between individuals and people, and construction-oriented perspective which has considered more important roles for the discovery ideas and thoughts in the development and shaping of these experiences, so there are essential differences of them between people and cultures. Intellectual system of Illumination, which has been developed according to Sohrevardi’s discussions, has unique and valuable view in this regard. It asserts that :::::union::::: with light underlies mystical revelation and the specific self-centeredness is involved in the realization of these experiences along with illumination, observation, :::::union:::::, and inexistence. Although characteristics of illumination and talent are essential in this system of thought, the collection of features regarding spiritual experiences, according to Sohrevardi, represents a kind of essence-orientation in mystical revelation. The personal unity of experiences based on the thinking of each individual does not mean to separate experiences. Rather, they all have common grounds. The present study first, refers to the views expressed in this regard, and then explains what and how of spiritual experiences from the viewpoint of Sohrevardi. It finally, provides answers to some unknown issues.

  13. Age management in Slovenian enterprises: the viewpoint of older employees

    Directory of Open Access Journals (Sweden)

    Jana Žnidaršič

    2010-12-01

    Full Text Available The main aim of this research is to highlight age management within Slovenian enterprises from the viewpoint of older employees by finding out what influences older employees to decide “should I stay or should I go”. The empirical research methodology is based on mixed strategy of approaching organizations (employees, which means that the quantitative (factor analysis, cluster analysis, correlation, regression, descriptive statistics and frequency distributions and qualitative parts (in-depth interviews analysis of research were conducted simultaneously. The results of the research indicate that there are in fact two groups of older employees, which can be referred to as “susceptible” and “insusceptible” in terms of how the employer can affect their decisions. “The unsusceptible” have already decided to retire as soon as possible and they cannot be influenced by any employer measure. On the other hand, “the susceptible” employees are sensitive to employers’ measures aimed at prolonging their working lives. Besides, a regression analysis confirmed a statistically significant correlation between the inclination towards extending one’s employment period and the susceptibility to the employer measures. It can thus be concluded that, through age management measures, an employer has an impact on an extended employment period of older employees. However, employers should be interested primarily in those employees who are inclined towards extending their working lives.

  14. Evaluating of Mashhad urban development plans from compact city viewpoint

    Directory of Open Access Journals (Sweden)

    Mohammad rahim Rahnama

    2013-09-01

    Full Text Available There are many problems especially in large cities due to producing of urban development plans in different time, on the other hand; changing traditional to strategies approach is other reason for creating today problems. Therefore, one of the main factors of sustainability development principles is smart growth by emphasis on compactly. Mashhad metropolitan need, presentation sustainable development pattern in urban development plans due to complex structure and important position. Due to, are prepared development plans in various times, should be adapted with sustainable development principles and compact city indicators. In this research at first were studied indicators of smart growth pattern, after that was evaluated development and comprehensive plans based on these principles. Finding of research show, although there is mentioned viewpoint in urban development plans but haven’t succeeded in order to achieving smart growth. On the other hand, Mashhad Middle West area is one of the main districts that smart growth principles are nearly, but it isn’t success completely.

  15. Ahl al-Bayt's Characteristics from Nahjol Balagheh's viewpoint

    Directory of Open Access Journals (Sweden)

    Mansour Darvishi Tafvizi

    2016-03-01

    Full Text Available The biggest challenge between Sunni and Shia has been the issue of Imamate throughout the history. Meanwhile the true meaning of Ahl al-Bayt has always been a disagreement between these two sects. The Shiite scholars claim that the term Ahl al-Bayt is truly applicable to Kasa companions whereas, the Sunni scholars have more than ten various ideas and narrations. Studying NahjolBalagheh viewpoint that is noticed by both Shiite and Sunni scholars can show the way to those who seek the truth. After examining what Imam Ali says about Ahl al-Bayt, we come across characteristics that do not deserve anybody else but Kasa companions and chaste Imams (peace be upon them. Characteristics such as Ahl al-Bayt are the basis of religion and the criteria of truth and justice, the angles are repeatedly sent to them, they are the resources of God on earth, the pillars of science and Imam Mahdi is among them. Neither the whole BaniHashim nor the wives of the prophet (God bless him and his family possess these features. And of course they themselves didn’t have such a claim and the claim was later alleged by some scholars who tried to create virtues for them.

  16. Carcinogenic effects ofcircadian disruption:an epigenetic viewpoint

    Institute of Scientific and Technical Information of China (English)

    Abbas Salavaty

    2015-01-01

    Circadian rhythms refer to the endogenous rhythms that are generated to synchronize physiology and behavior with 24-h environmental cues. These rhythms are regulated by both external cues and molecular clock mechanisms in almost all cells. Disruption of circadian rhythms, which is called circadian disruption, affects many biological processes within the body and results in different long-term diseases, including cancer. Circadian regulatory pathways result in rhythmic epigenetic modiifcations and the formation of circadian epigenomes. Aberrant epigenetic modiifcations, such as hypermethylation, due to circadian disruption may be involved in the transformation of normal cells into cancer cells. Several studies have indicated an epigenetic basis for the carcinogenic effects of circadian disruption. In this review, I ifrst discuss some of the circadian genes and regulatory proteins. Then, I summarize the current evidence related to the epigenetic modiifcations that result in circadian disruption. In addition, I explain the carcinogenic effects of circadian disruption and highlight its potential role in different human cancers using an epigenetic view-point. Finally, the importance of chronotherapy in cancer treatment is highlighted.

  17. Cost assessment of bioethanol from the viewpoint of consumer

    Energy Technology Data Exchange (ETDEWEB)

    Anahideh, H.; Nourbakhsh, S. H.; Shakouri G, H. [Department of Industrial Engineering, Engineering Collage, University of Tehran (Iran, Islamic Republic of)], e-mail: h.anahideh@ut.ac.ir, email: nourbakhsh@ut.ac.ir, email: hshakouri@ut.ac.ir

    2011-07-01

    Demand for transportation fuels has risen progressively over the last decade. Utilization of biomass waste as a raw material for future energy production has attracted a good deal of attention as an alternative to petroleum based fuels, the primary source of energy for transportation at present. Today, bioethanol, an alcohol made by fermentation, is probably the most used non-fossil alternative transport biofuel in the world. It is usually used as a gasoline additive to increase octane and improve vehicle emissions. This paper presents a cost assessment of fuels E-10, E-85 and gasoline from the viewpoint of the consumer. The imposed costs to the consumer are calculated as well as the hidden costs, which the consumer may not notice. The price of a tank of E-85 is found to be greater than that of a tank of gasoline but the environmental cost of it is much less than that of either E-10 or gasoline. The price of E-10, on the other hand, is the same as the price of gasoline but its cost, in terms of CO2 emissions, is lower.

  18. Carcinogenic effects of circadian disruption: an epigenetic viewpoint.

    Science.gov (United States)

    Salavaty, Abbas

    2015-08-08

    Circadian rhythms refer to the endogenous rhythms that are generated to synchronize physiology and behavior with 24-h environmental cues. These rhythms are regulated by both external cues and molecular clock mechanisms in almost all cells. Disruption of circadian rhythms, which is called circadian disruption, affects many biological processes within the body and results in different long-term diseases, including cancer. Circadian regulatory pathways result in rhythmic epigenetic modifications and the formation of circadian epigenomes. Aberrant epigenetic modifications, such as hypermethylation, due to circadian disruption may be involved in the transformation of normal cells into cancer cells. Several studies have indicated an epigenetic basis for the carcinogenic effects of circadian disruption. In this review, I first discuss some of the circadian genes and regulatory proteins. Then, I summarize the current evidence related to the epigenetic modifications that result in circadian disruption. In addition, I explain the carcinogenic effects of circadian disruption and highlight its potential role in different human cancers using an epigenetic viewpoint. Finally, the importance of chronotherapy in cancer treatment is highlighted.

  19. [Impact of backward sexual viewpoints on population development].

    Science.gov (United States)

    Wang, B

    1991-04-01

    In the development of human society, the reproductive function was considered the sole purpose of sexual activities. Any other purposes were deemed abnormal or deviant. The prevalence of that viewpoint reflected the needs during the transformation from hunting to farming as major means of production of the society and the needs for large populations under the socioeconomic conditions of rural society. With the low level of productivity in a family-oriented economy, further development depended on the number of labor hands in the family. The wars for extension of territory and for survival need a constant supply of soldiers. Under such circumstances, the need for large populations implied the importance of fertility behavior in sexual relations. In the rural farming societies, fertility was important in strengthening and developing the family wealth, status, and family structure. Blood relations were emphasized in rural society for family inheritance, for expansion of family influence, and for old age support. The rapid decline of fertility in Europe at the beginning of this century was proposed by some Chinese scholars as the result of their citizens pursuing individual happiness including in sexual relations. The use of contraceptives prevented couples from being overburdened with children. These concepts on sexual relations facilitated the decline of fertility. The necessary social and economic conditions and advances in technology are already present for the changes of the traditional concepts toward sexual relations. The united efforts of social agencies in promoting these changes will be an efficient ensure in regulating the speed of population growth.

  20. Patient advocacy from the clinical nurses' viewpoint: a qualitative study

    Science.gov (United States)

    Davoodvand, Shirmohammad; Abbaszadeh, Abbas; Ahmadi, Fazlollah

    2016-01-01

    One of the advanced nursing care procedures emphasized by nursing organizations around the world is patient or nursing advocacy. In addition to illustrating the professional power of nursing, it helps to provide effective nursing care. The aim of the present study was to explain the concept of patient advocacy from the perspective of Iranian clinical nurses. This was a qualitative study that examined the viewpoint and experiences of 15 clinical nurses regarding patient advocacy in nursing. The nurses worked in intensive care units (ICUs), coronary care units (CCUs), and emergency units. The study participants were selected via purposeful sampling. The data was collected through semi-structured interviews and analyzed using content analysis. Data analysis showed that patient advocacy consisted of the two themes of empathy with the patient (including understanding, being sympathetic with, and feeling close to the patient) and protecting the patients (including patient care, prioritization of patients’ health, commitment to the completion of the care process, and protection of patients' rights). The results of this study suggest that nurses must be empathetic toward and protective of their patients. The results of the present study can be used in health care delivery, nursing education, and nursing management and planning systems to help nurses accomplish their important role as patient advocates. It is necessary to further study the connections between patient advocacy and empathy. PMID:27471588

  1. Patient advocacy from the clinical nurses' viewpoint: a qualitative study.

    Science.gov (United States)

    Davoodvand, Shirmohammad; Abbaszadeh, Abbas; Ahmadi, Fazlollah

    2016-01-01

    One of the advanced nursing care procedures emphasized by nursing organizations around the world is patient or nursing advocacy. In addition to illustrating the professional power of nursing, it helps to provide effective nursing care. The aim of the present study was to explain the concept of patient advocacy from the perspective of Iranian clinical nurses. This was a qualitative study that examined the viewpoint and experiences of 15 clinical nurses regarding patient advocacy in nursing. The nurses worked in intensive care units (ICUs), coronary care units (CCUs), and emergency units. The study participants were selected via purposeful sampling. The data was collected through semi-structured interviews and analyzed using content analysis. Data analysis showed that patient advocacy consisted of the two themes of empathy with the patient (including understanding, being sympathetic with, and feeling close to the patient) and protecting the patients (including patient care, prioritization of patients' health, commitment to the completion of the care process, and protection of patients' rights). The results of this study suggest that nurses must be empathetic toward and protective of their patients. The results of the present study can be used in health care delivery, nursing education, and nursing management and planning systems to help nurses accomplish their important role as patient advocates. It is necessary to further study the connections between patient advocacy and empathy.

  2. A Study of Sanandaj Traditional Bazaar from a Phenomenological Viewpoint

    Directory of Open Access Journals (Sweden)

    A. Farsi

    2015-08-01

    Full Text Available The phenomenon of Sanandaj Traditional Bazaar is a complete and complex set of economic, cultural and social activities. A reasonable harmony has gradually developed between the various aspects of the Bazaar and its architecture in spite of all these complexities. Thus it seems that this phenomenon involves valuable but hidden structures, whose understanding is possible only in a constructive interaction with the space, its users and the shopkeepers. The purpose of this study is to explain the Sanandaj Traditional Bazaar phenomenon as reflected in the experiences of the users and shopkeepers through a phenomenological viewpoint and by relying on the views of philosophers such as Gadamer and Heidegger. The research method is phenomenological hermeneutics, and depth semi-structured interviews with eleven shopkeepers and users were conducted in this study. Finally, nineteen new semantic horizons of Sanandaj Traditional Bazaar emerged. The violation of the main passage by the shopkeepers as an authentic behavior, the communicational function of Bazaar, the combination of the concept of Sanandaj Traditional Bazaar with the historic event of the construction of Enghelab Street, the comfort and intimacy in communications within the Bazaar and incomprehensible natural passage of time in the Bazaar due to the physical structure of the Bazaar, are the main results of this paper.

  3. Virtual reality: Avatars in human spaceflight training

    Science.gov (United States)

    Osterlund, Jeffrey; Lawrence, Brad

    2012-02-01

    familiarize and assess operational processes, allow the ability to train virtually, experiment with "what if" scenarios, and expedite immediate changes to validate the design implementation are all parameters of interest in human spaceflight. Training benefits encompass providing 3D animation for post-training assessment, placement of avatars within 3D replicated work environments in assembling or processing hardware, offering various viewpoints of processes viewed and assessed giving the evaluators the ability to assess task feasibility and identify potential support equipment needs; and provide human factors determinations, such as reach, visibility, and accessibility. Multiple object motion capture technology provides an effective tool to train and assess ergonomic risks, simulations for determination of negative interactions between technicians and their proposed workspaces, and evaluation of spaceflight systems prior to, and as part of, the design process to contain costs and reduce schedule delays.

  4. High availability using virtualization

    CERN Document Server

    Calzolari, Federico

    2009-01-01

    High availability has always been one of the main problems for a data center. Till now high availability was achieved by host per host redundancy, a highly expensive method in terms of hardware and human costs. A new approach to the problem can be offered by virtualization. Using virtualization, it is possible to achieve a redundancy system for all the services running on a data center. This new approach to high availability allows to share the running virtual machines over the servers up and running, by exploiting the features of the virtualization layer: start, stop and move virtual machines between physical hosts. The system (3RC) is based on a finite state machine with hysteresis, providing the possibility to restart each virtual machine over any physical host, or reinstall it from scratch. A complete infrastructure has been developed to install operating system and middleware in a few minutes. To virtualize the main servers of a data center, a new procedure has been developed to migrate physical to virtu...

  5. COMPANION ANIMALS SYMPOSIUM: Rendered ingredients significantly influence sustainability, quality, and safety of pet food.

    Science.gov (United States)

    Meeker, D L; Meisinger, J L

    2015-03-01

    The rendering industry collects and safely processes approximately 25 million t of animal byproducts each year in the United States. Rendering plants process a variety of raw materials from food animal production, principally offal from slaughterhouses, but include whole animals that die on farms or in transit and other materials such as bone, feathers, and blood. By recycling these byproducts into various protein, fat, and mineral products, including meat and bone meal, hydrolyzed feather meal, blood meal, and various types of animal fats and greases, the sustainability of food animal production is greatly enhanced. The rendering industry is conscious of its role in the prevention of disease and microbiological control and providing safe feed ingredients for livestock, poultry, aquaculture, and pets. The processing of otherwise low-value OM from the livestock production and meat processing industries through rendering drastically reduces the amount of waste. If not rendered, biological materials would be deposited in landfills, burned, buried, or inappropriately dumped with large amounts of carbon dioxide, ammonia, and other compounds polluting air and water. The majority of rendered protein products are used as animal feed. Rendered products are especially valuable to the livestock and pet food industries because of their high protein content, digestible AA levels (especially lysine), mineral availability (especially calcium and phosphorous), and relatively low cost in relation to their nutrient value. The use of these reclaimed and recycled materials in pet food is a much more sustainable model than using human food for pets.

  6. Evaluating students’ perception of a three-dimensional virtual world learning environment

    Directory of Open Access Journals (Sweden)

    Michael Chau

    2013-09-01

    Full Text Available Three-dimensional virtual environments have gained wide popularity due to improvement in graphic rendering technology and networking infrastructure. Many education institutions have been trying to leverage the potential of 3D virtual environments in their application in education. In this research, we aim to evaluate the students’ perception of virtual environments in teaching and learning activities. We set up a virtual classroom, where a short presentation was delivered to students through virtual projectors in Second Life, the most widely adopted 3D virtual environment. The students filled in a questionnaire after the class. We found that the students gave a statistically higher evaluation to 3D virtual environments in terms of satisfaction and enjoyment, while comparable scores between 3D and traditional learning environment in terms of concentration, perceived usefulness, and learning and understanding were obtained. Our results show that virtual learning environment is of great potential in e-learning. Some recommendations in using the virtual environment for learning activities are given.

  7. The Study of Three-dimensional Product Rendering Based on the Photography Studio Model%基于摄影棚模式的计算机三维产品渲染研究

    Institute of Scientific and Technical Information of China (English)

    雷鸿源

    2014-01-01

    通过对产品摄影的评价因素和对摄影棚拍摄特点的分析,分别以白色和黑色为渲染背景,建立了基于摄影棚模式的三维产品渲染流程。在虚拟摄影棚左侧、右侧和顶部建立三盏不同的矩形灯光,并结合材质设置和渲染参数设置,就能够渲染出白色背景的精美产品效果图;黑色背景的渲染是以一盏背景灯将产品从黑色背景中烘托出来,并利用模糊倒影来增强产品的立体感;还分析了产品渲染中实景匹配的两种方式,并提出透明材质物体渲染的注意事项。以渲染器Vray为实验平台,渲染结果真实度高。%Through the analysis of the evaluation factors of the products ’ photographs and the characteristics of the photography studio ,this pa-per has established three-dimensional product rendering process based on the photography studio model with white and black background re-spectively .With three different rectangular lights on the left ,the right and the top of the virtual photography studio and combined with material settings and rendering parameters settings ,beautiful product renderings with white background can be rendered .Black background rendering is to heighten products of black background with the background light and to enhance the three -dimensional effects of the products using fuzzy inverted image .This paper has analyzed 2 methods of virtual match of rendering and proposed some precautions of the renderings of objects with transparent materials .The experiments are based on Vray with vivid and real rendering effect .

  8. Spatial and viewpoint selectivity for others' observed actions in monkey ventral premotor mirror neurons.

    Science.gov (United States)

    Maranesi, Monica; Livi, Alessandro; Bonini, Luca

    2017-08-15

    The spatial location and viewpoint of observed actions are closely linked in natural social settings. For example, actions observed from a subjective viewpoint necessarily occur within the observer's peripersonal space. Neurophysiological studies have shown that mirror neurons (MNs) of the monkey ventral premotor area F5 can code the spatial location of live observed actions. Furthermore, F5 MN discharge can also be modulated by the viewpoint from which filmed actions are seen. Nonetheless, whether and to what extent MNs can integrate viewpoint and spatial location of live observed actions remains unknown. We addressed this issue by comparing the activity of 148 F5 MNs while macaque monkeys observed an experimenter grasping in three different combinations of viewpoint and spatial location, namely, lateral view in the (1) extrapersonal and (2) peripersonal space and (3) subjective view in the peripersonal space. We found that the majority of MNs were space-selective (60.8%): those selective for the peripersonal space exhibited a preference for the subjective viewpoint both at the single-neuron and population level, whereas space-unselective neurons were view invariant. These findings reveal the existence of a previously neglected link between spatial and viewpoint selectivity in MN activity during live-action observation.

  9. The Virtual Dressing Room

    DEFF Research Database (Denmark)

    Holte, Michael Boelstoft; Gao, Yi; Petersson, Eva

    2015-01-01

    This paper presents the design and evaluation of a usability and user experience test of a virtual dressing room. First, we motivate and introduce our recent developed prototype of a virtual dressing room. Next, we present the research and test design grounded in related usability and user experi...... experience studies. We give a description of the experimental setup and the execution of the designed usability and user experience test. To this end, we report interesting results and discuss the results with respect to user-centered design and development of a virtual dressing room....

  10. Virtually Abelian quantum walks

    Science.gov (United States)

    Mauro D'Ariano, Giacomo; Erba, Marco; Perinotti, Paolo; Tosini, Alessandro

    2017-01-01

    We study discrete-time quantum walks on Cayley graphs of non-Abelian groups, focusing on the easiest case of virtually Abelian groups. We present a technique to reduce the quantum walk to an equivalent one on an Abelian group with coin system having larger dimension. This method allows one to extend the notion of wave-vector to the virtually Abelian case and study analytically the walk dynamics. We apply the technique in the case of two quantum walks on virtually Abelian groups with planar Cayley graphs, finding the exact solution in terms of dispersion relation.

  11. The virtual Haken conjecture

    CERN Document Server

    Agol, Ian; Manning, Jason

    2012-01-01

    We prove that cubulated hyperbolic groups are virtually special. The proof relies on results of Haglund and Wise which also imply that they are linear groups, and quasi-convex subgroups are separable. A consequence is that closed hyperbolic 3-manifolds have finite-sheeted Haken covers, which resolves the virtual Haken question of Waldhausen and Thurston's virtual fibering question. An appendix to this paper by Agol, Groves, and Manning proves a generalization of the main result of "Residual finiteness, QCERF and fillings of hyperbolic groups".

  12. Virtual Reality Musical Instruments

    DEFF Research Database (Denmark)

    Serafin, Stefania; Erkut, Cumhur; Kojs, Juraj

    2016-01-01

    The rapid development and availability of low-cost technologies have created a wide interest in virtual reality. In the field of computer music, the term “virtual musical instruments” has been used for a long time to describe software simulations, extensions of existing musical instruments......, and ways to control them with new interfaces for musical expression. Virtual reality musical instruments (VRMIs) that include a simulated visual component delivered via a head-mounted display or other forms of immersive visualization have not yet received much attention. In this article, we present a field...

  13. Virtual Reality Musical Instruments

    DEFF Research Database (Denmark)

    Serafin, Stefania; Erkut, Cumhur; Kojs, Juraj

    2016-01-01

    The rapid development and availability of low-cost technologies have created a wide interest in virtual reality. In the field of computer music, the term “virtual musical instruments” has been used for a long time to describe software simulations, extensions of existing musical instruments......, and ways to control them with new interfaces for musical expression. Virtual reality musical instruments (VRMIs) that include a simulated visual component delivered via a head-mounted display or other forms of immersive visualization have not yet received much attention. In this article, we present a field...

  14. TractRender: a new generalized 3D medical image visualization and output platform

    Science.gov (United States)

    Hwang, Darryl H.; Tsao, Sinchai; Gajawelli, Niharika; Law, Meng; Lepore, Natasha

    2015-01-01

    Diffusion MRI allows us not only voxelized diffusion characteristics but also the potential to delineate neuronal fiber path through tractography. There is a dearth of flexible open source tractography software programs for visualizing these complicated 3D structures. Moreover, rendering these structures using various shading, lighting, and representations will result in vastly different graphical feel. In addition, the ability to output these objects in various formats increases the utility of this platform. We have created TractRender that leverages openGL features through Matlab, allowing for maximum ease of use but still maintain the flexibility of custom scene rendering.

  15. Methods for Quantifying and Characterizing Errors in Pixel-Based 3D Rendering.

    Science.gov (United States)

    Hagedorn, John G; Terrill, Judith E; Peskin, Adele P; Filliben, James J

    2008-01-01

    We present methods for measuring errors in the rendering of three-dimensional points, line segments, and polygons in pixel-based computer graphics systems. We present error metrics for each of these three cases. These methods are applied to rendering with OpenGL on two common hardware platforms under several rendering conditions. Results are presented and differences in measured errors are analyzed and characterized. We discuss possible extensions of this error analysis approach to other aspects of the process of generating visual representations of synthetic scenes.

  16. Using Virtual Reality For Outreach Purposes in Planetology

    Science.gov (United States)

    Civet, François; Le Mouélic, Stéphane; Le Menn, Erwan; Beaunay, Stéphanie

    2016-10-01

    2016 has been a year marked by a technological breakthrough : the availability for the first time to the general public of technologically mature virtual reality devices. Virtual Reality consists in visually immerging a user in a 3D environment reproduced either from real and/or imaginary data, with the possibility to move and eventually interact with the different elements. In planetology, most of the places will remain inaccessible to the public for a while, but a fleet of dedicated spacecraft's such as orbiters, landers and rovers allow the possibility to virtually reconstruct the environments, using image processing, cartography and photogrammetry. Virtual reality can then bridge the gap to virtually "send" any user into the place and enjoy the exploration.We are investigating several type of devices to render orbital or ground based data of planetological interest, mostly from Mars. The most simple system consists of a "cardboard" headset, on which the user can simply use his cellphone as the screen. A more comfortable experience is obtained with more complex systems such as the HTC vive or Oculus Rift headsets, which include a tracking system important to minimize motion sickness. The third environment that we have developed is based on the CAVE concept, were four 3D video projectors are used to project on three 2x3m walls plus the ground. These systems can be used for scientific data analysis, but also prove to be perfectly suited for outreach and education purposes.

  17. Virtual Reality and its Implementation in Transport Ergonomics

    Directory of Open Access Journals (Sweden)

    Jasna Jurum-Kipke

    2007-03-01

    Full Text Available The experience of our environment is based on the informationthat reach us by means of our sensory organs, andwhich are subsequently processed in our brains. Digital interpretationimplemented to mathematical models of the studiedsubjects brings us to the so-called virtual reality that allows us toreplace some natural human senses, in this case the visualones, by computer-generated infonnation. The procedure is expandedto three-dimensional (3D scanning i. e. searching ofthe special form of the obse1ved subject/object, then digital recordingof the space point cloud (pixels which correspond tothe item, then vectorisation of the fonn, rendering and finallyanimation. In this way, by watching the display, the impressionof the virtual environment can be generated in the human perception.Moreover, in this way the human model can be realizedin a characteristic way in such a virtual space. The implementationof this virtual reality, in accordance with the possibilitiesthat it provides, has been the subject of very intensive researchin the world, and in Croatia as well. The work presentssome possibilities of applying virtual reality in the field of ergonomicanalysis of the collision process of two vehicles.

  18. The students’ viewpoint on the quality gap in educational services

    Science.gov (United States)

    RAHIM KHANLI, MARZIYEH; DANESHMANDI, HADI; CHOOBINEH, ALIREZA

    2014-01-01

    Introduction: Students and university community are social and human resources of the country. The students’ viewpoints about the quality of educational services can be considered as a basis for planning quality promotion and improving organizational performance. This study was conducted to determine the quality gap in educational services by the students of Health and Nutrition School of Shiraz University of Medical Sciences. Methods: In this cross-sectional study, 140 students participated voluntarily (age range=19 to 40 years). The service quality (SERVQUAL) questionnaire was used for data collection. This questionnaire measured the quality gap in 5 dimensions of educational service including assurance, responsiveness, empathy, reliability, and tangibility. The students’ perception about the current conditions and their expectations as to optimal conditions can be determined, using this questionnaire. The score of the gap in quality of educational services is calculated from difference between perception and expectation scores. Due to non-normality of data, non-parametric tests were used. To this end, data were analyzed by statistical tests including Wilcoxon, Friedman, Kruskal-Wallis and Mann-Whiteny tests in SPSS 14. Results: The results showed that there was quality gap in all 5 dimensions of educational services. The largest and the smallest gaps were observed in "responsiveness" with a mean±SD of -0.94±0.74 and in "reliability" with a mean±SD of -0.76±0.69, respectively. There was a significant difference in quality gap between the 5 dimensions (p<0.001). Conclusion: According to the results, the students’ expectations were higher than their perceptions of current conditions; also, in all aspects of the services their expectations were not met. It is recommended that workshops on customer services, communication skills and personnel’s technical skills development should be planned and held. Also, allocating more resources for improving

  19. The students' viewpoint on the quality gap in educational services

    Directory of Open Access Journals (Sweden)

    MARZIYEH RAHIM-KHANLI

    2014-07-01

    Full Text Available Introduction: Students and university community are social and human resources of the country. The students’ viewpoints about the quality of educational services can be considered as a basis for planning quality promotion and improving organizational performance. This study was conducted to determine the quality gap in educational services by the students of Health and Nutrition School of Shiraz University of Medical Sciences. Methods: In this cross-sectional study, 140 students participated voluntarily (age range=19 to 40 years. The service quality (SERVQUAL questionnaire was used for data collection. This questionnaire measured the quality gap in 5 dimensions of educational service including assurance, responsiveness, empathy, reliability, and tangibility. The students’ perception about the current conditions and their expectations as to optimal conditions can be determined, using this questionnaire. The score of the gap in quality of educational services is calculated from difference between perception and expectation scores. Due to non-normality of data, non-parametric tests were used. To this end, data were analyzed by statistical tests including Wilcoxon, Friedman, Kruskal-Wallis and Mann-Whiteny tests in SPSS 14. Results: The results showed that there was quality gap in all 5 dimensions of educational services. The largest and the smallest gaps were observed in "responsiveness" with a mean±SD of -0.94±0.74 and in "reliability" with a mean±SD of -0.76±0.69, respectively. There was a significant difference in quality gap between the 5 dimensions (p<0.001. Conclusion: According to the results, the students’ expectations were higher than their perceptions of current conditions; also, in all aspects of the services their expectations were not met. It is recommended that workshops on customer services, communication skills and personnel’s technical skills development should be planned and held. Also, allocating more resources for

  20. The Students’ Viewpoint on Quality of Educational Services in Iran

    Science.gov (United States)

    Siamian, Hasan; Rostami, Farideh; Ghara, Aliasghar Nadi; Abedi, Ghassem

    2017-01-01

    Background: Recently, focusing on higher education quality has got increasingly critical. The novel managerial attitudes have defined the customer-demanded quality. Based on this, recognizing the receivers’ perception of the quality of the services offered and evaluating the quality of the service is considered of the basic measures taken in order to develop quality promotion programs. Therefore, this is a qualitative research conducted for students’ viewpoint on quality of educational services. Material and Methods: This qualitative study has been performed by the phenomenological method. The samples have been selected based on goal-oriented approach. In this qualitative research, the required data have been collected in two phases (90 individual interviews and 30 focus group discussions) at Mazandaran University of Medical Sciences during which the participants have conveyed their experiences and expectations encountering the educational quality topic. All the interviews have been recorded and implemented. The interviews analysis has been carried out simultaneously with the implementation and using theme analysis by Smith method. Results: According to the findings regarding the definition of quality, the students have emphasized two important aspects including “educational services standards by the teacher “and “the students’ satisfaction”. Thus the final education quality resulted from the students’ experiences and perception is this way: “Presenting the students educational services in class and out of class compatible with the educational services standards so that it results in the students’ satisfaction”. When a person views her/him-self rightful as a customer, whatever seems necessary to them appears like a requirement. Then regarding paying attention and reflecting on the customers’ perceived needs, it is possible to determine their expectations limit to some extent. Conclusion: Therefore, designing educational quality standards in