Shading Schemes Research Articles

Scaling Byzantine Fault-Tolerant Consensus With Optimized Shading Scheme

Scaling Byzantine Fault-Tolerant Consensus With Optimized Shading Scheme

Offline character recognition in transport logistic tables

The paper proposes the improved skeleton method of handwritten characters recognition, which is based on the filtering procedure and the principle of alternating shading schemes of skeletonized area on the 4- and 8-timeslinked raster. The procedure of high-frequency filtration based on discrete real cosine transformation or discrete complex Fourier transform with automatic selection of filtration parameters makes it possible to significantly improve the image quality of handwritten symbols, in particular, to eliminate in many cases thin bridges between the areas of symbol element representation. The principle of alternating the painting schemes along the 4- and 8-timeslinked raster makes it possible to get the wave front of the skeletonized area close to a circle. In this case, the broken lines representing the branches of the skeleton graphs retain the shapes of the symbols. Numerical experiments on the construction of skeleton sets and skeleton graphs for recognizable handwritten symbols located in the cells of the tables of logistic transport problems have been performed. Software implementation of the method is proposed.

Reconfigurable Patterns of Photovoltaic Cells to Reduce Power Loss due to Detrimental Shading Conditions

Poorly illuminated or defective photovoltaic cells (PV cells) affect the performance of the whole panel. In this work, we propose a methodology to discover the best connection pattern among cells in a panel under unfavorable shading conditions. It is, therefore, assumed that the target PV module allows internal disconnection and reconnection of neighboring cells. In order to manage the reconfiguration of the cells on the array, the developed algorithm searches for the connection pattern that yields the least power loss, taking into account the cell model in silicon and the effect of shading. Three progressive shading schemes have been applied to mimic possible hard shading on a 36-cell panel. For each case, the algorithm analyzed the IV-characteristics of the panel and suggested the best cell-connection pattern to achieve the highest power output under each condition. When less than 15 of the 36 PV cells were affected by shading, the algorithm was able to present up to 30% reduction in power loss when compared to the standard configuration, and up to 20% reduction when compared to complex fixed connection patterns. For shading patterns where 15 or more PV cells were affected, reconnection of the cells did not result in a reduction of power loss. However, if the PV panel is properly installed, only marginal hard shading should be expected and the algorithm would represent a promising tool to be deployed dynamically by means of switches and a management unit coupled to the panel.

A Tool for Stereoscopic Parameter Setting Based on Geometric Perceived Depth Percentage

It is a necessary but challenging task for creative producers to have an idea of the depth perception of the target audience when watching a stereoscopic film in a cinema during production. This paper proposes a novel metric, geometric perceived depth percentage (GPDP), to numerate and depict the depth perception of a scene before rendering. In addition to the geometric relationship between the object depth and focal distance, GPDP takes the screen width and viewing distance into account. As a result, it provides a more intuitive means for predicting stereoscopy and is universal across different viewing conditions. Based on GPDP, we design a practical tool to visualize the stereoscopic perception without the need for any 3-D device or special environment. The tool utilizes the stereoscopic comfort volume, GPDP-based shading schemes, depth perception markers, and GPDP histograms as visual cues so that animators can set stereoscopic parameters more easily. The tool is easily implemented in any modern rendering pipeline, including interactive Autodesk Maya and offline Pixar’s RenderMan renderer. It has been used in several production projects including commercial ones. Finally, two user studies show that GPDP is a proper depth perception indicator and the proposed tool can make the stereoscopic parameter setting process easier and more efficient.

A Study on the Impact of Household Occupants’ Behavior on Energy Consumption Using an Integrated Computer Model

In this paper, several models are integrated into a thermal model to study the impact of occupants’ behaviors on the building energy consumption. An air flow model is developed to simulate ventilation related to the occupant’s patterns of window opening and closing. An electric consumption model is developed to simulate the usage pattern and the electricity input to household electric appliances. The thermostat setpoint temperature and window shading schemes are varied with different occupants’ behavior norms and are included in the model. The simulation was applied to a typical household located in the city of Oshawa in Ontario, Canada. The results show that the window opening has the greatest impact on the energy consumption during the heating season, and the shading scheme has the greatest impact on the A/C energy consumption during the cooling season. The electricity consumption of the A/C can be significantly reduced by appropriately applying the shading and opening schemes and resetting the thermostat setpoint temperature to a slightly higher degree. Keeping the windows closed and allowing the solar radiation to be transmitted through the window in winter help reduce the energy usage to heat the house.

A Multi-Channel Salience Based Detail Exaggeration Technique for 3D Relief Surfaces

Visual saliency can always persuade the viewer's visual attention to fine-scale mesostructure of 3D complex shapes. Owing to the multi-channel salience measure and salience-domain shape modeling technique, a novel visual saliency based shape depiction scheme is presented to exaggerate salient geometric details of the underlying relief surface. Our multi-channel salience measure is calculated by combining three feature maps, i.e., the 0-order feature map of local height distribution, the 1-order feature map of normal difference, and the 2-order feature map of mean curvature variation. The original relief surface is firstly manipulated by a salience-domain enhancement function, and the detail exaggeration surface can then be obtained by adjusting the surface normals of the original surface as the corresponding final normals of the manipulated surface. The advantage of our detail exaggeration technique is that it can adaptively alter the shading of the original shape to reveal visually salient features whilst keeping the desired appearance unimpaired. The experimental results demonstrate that our non-photorealistic shading scheme can enhance the surface mesostructure effectively and thus improving the shape depiction of the relief surfaces.

Development and Implementation of Lighting and Shading Control Algorithms in an Airport Building

This paper presents the development and implementation of shading and lighting control schemes in an airport building. The airport has several perimeter zones with large glass facades that receive excessive solar gains throughout the year. Starting from a large southwest zone, illuminance sensors were installed in strategic positions and interior daylight levels were monitored under various sky conditions and shade positions. Analysis of the results allowed derivation of reliable correlations between ceiling and work plane illuminances, which were used to develop control schemes for shading and lighting operation. After successful implementation, the project moved to the next phase, which included all the perimeter zones in the airport. In this phase, only one sensor was installed on the ceiling of each zone, and illuminance levels were predicted using simulation models and validated with a few manual measurements. The developed control schemes were implemented in all perimeter zones of the airport. The study also includes simulation results for the potential energy savings owing to reduced lighting and cooling energy demand.

Effectiveness of SRTM and ALOS-PALSAR data for identifying morphostructural lineaments in northeastern Brazil

This work provides a comparison between ALOS (Advanced Land Observing Satellite) PALSAR (Phased Array type L-band Synthetic Aperture Radar) and DEM (Digital Elevation Model) SRTM (Shuttle Radar Topography Mission) data aiming to evaluate their efficiency to detect morphostructural lineaments. An area in Northeastern Brazil was selected to perform this investigation because of its unambiguous evidence of tectonic fault activity from the Precambrian to the Quaternary. DEM enhanced by shading schemes and palettes was integrated with images representative of morphometric variables as aspect and horizontal curvature in order to enable the recognition of linear features. Images derived from HIS transformation and arithmetic operations of fine beam dual (HH+HV) polarization PALSAR images were processed to provide RGB compositions. Comparisons among lineament maps based on these two remote-sensing products attest to the highest efficacy of SRTM data in detecting geologically meaningful lineaments in the study area. These indicate a main E–W trend and secondary, NE–SW and NW–SE trends, which conform to dominant directions of tectonic fault zones previously mapped in northeastern Brazil. Geomorphological and geological field investigations carried out in the course of the current research further contributed to showing the best performance of this product for unravelling details of three expressive tectonic structures in the study area. This study shows that lineament attenuation in PALSAR images augments proportionally with increased land use. Other important interferences that either rule out or significantly attenuate linear structures are imposed by natural characteristics of the L-band PALSAR sensor, including layover and high-look azimuth in equatorial latitude. The latter might have particularly attenuated detection of lineaments parallel to illumination azimuth. Taking into account these interferences in PALSAR images, integration of DEM-SRTM data used herein offers a much more robust tool to help carry out morphostructural studies in terrains displaying characteristics similar to the ones in the study area.

Razor

Recent work demonstrates that interactive ray tracing is possible on desktop systems, but there is still much debate as to how to most efficiently support advanced visual effects such as soft shadows, smooth freeform surfaces, complex shading, and animated scenes. With these challenges in mind, we reconsider the options for designing a rendering system and present Razor , a new software rendering architecture for distribution ray tracing designed to produce high-quality images with high performance on future single-chip many-core hardware. Razor includes two noteworthy capabilities: a set of techniques for quickly building the kd-tree acceleration structure on demand every frame from a scene graph and a system design that allows for crack-free multiresolution geometry with each ray independently choosing its geometry resolution. Razor's per-frame kd-tree build is designed to robustly handle arbitrarily scene animation, while its per-ray multiresolution geometry provides continuous level of detail driven by ray and path differentials. Razor also decouples shading from visibility computations using a two-phase shading scheme inspired by the REYES system, and caches tessellated representations of freeform surfaces at multiple levels of detail. We present experimental results gathered from a prototype system implemented on eight CPU cores, and discuss which aspects of the system are most successful and which would benefit from further investigation.

Visual saliency guided normal enhancement technique for 3D shape depiction

Visual saliency can effectively guide the viewer's visual attention to salient regions of a 3D shape. Incorporating the visual saliency measure of a polygonal mesh into the normal enhancement operation, a novel saliency guided shading scheme for shape depiction is developed in this paper. Due to the visual saliency measure of the 3D shape, our approach will adjust the illumination and shading to enhance the geometric salient features of the underlying model by dynamically perturbing the surface normals. The experimental results demonstrate that our non-photorealistic shading scheme can enhance the depiction of the underlying shape and the visual perception of its salient features for expressive rendering. Compared with previous normal enhancement techniques, our approach can effectively convey surface details to improve shape depiction without impairing the desired appearance.

Using Multiple Sequence Alignment Editors and Formatters: Figure 1.

Sequence alignment editors enable the user to manually edit a multiple sequence alignment (msa) in order to obtain a more reasonable or expected alignment. Editors allow sequences to be reordered and/or modified using the computer's cut and paste commands. They are designed to accept various msa formats and to provide the output file in a suitable user-designated format. Sequence formatters provide various output formatting options, such as color and shading schemes to enhance visualization of residue alignments. The formatters can output files in Postscript, EPS, RTF, and other widely recognized formats, while accepting the standard input formats, such as MSF, ALN, and FASTA. This article introduces a number of sequence alignment editors and formatters, and provides links to sites where they can be found.

Robust optimal shading scheme for adaptive beamforming with missing sensor elements

A new technique for re-computing shading parameters for low sidelobe levels for a radar or sonar system is disclosed. When some of the sensor elements become inoperative, remaining shading parameters are recomputed using a new constraint. This approach leads to an overall gain pattern that is superior compared to the one without re-computing the weights.

Real-Time Point-Based Rendering Using Visibility Map

Because of its simplicity and intuitive approach, point-based rendering has been a very popular research area. Recent approaches have focused on hardware-accelerated techniques. By applying a deferred shading scheme, both high-quality images and high-performance rendering have been achieved. However, previous methods showed problems related to depth-based visibility computation. We propose an extended point-based rendering method using a visibility map. In our method we employ a distance-based visibility technique (replacing depth-based visibility), an averaged position map and an adaptive fragment processing scheme, resulting in more accurate and improved image quality, as well as improved rendering performance.

Fast restoration of large area breakdown for power distribution systems

An adjacent table-based simplified model of distribution networks containing medium voltage buses of a substation is established. Identification of bus outage and the condition to start fast restoration procedure are discussed. A complex load shading parameter is set up to describe various load shading schemes. The imaginary part of the load shading parameter describes the states of switches of load shading schemes while the real part is the corresponding amount of shaded load. A new concept of independent tripping operation is also put forward. The procedure to search the operation with the least amount of shaded load for a feeder and a connected domain are detailed. The procedure for fast restoration of a large area breakdown of the whole distribution network under emergency states is dealt with using a typical grid distribution network as an example. Results of analysis show that the direct load shading scheme under the most balanced topology is not always the optimal scheme. The proposed method can obtain the optimal operating mode with the least amount of shaded load thus showing its feasibility.

Functional Insights from the Structure of the Multifunctional C345C Domain of C5 of Complement

The complement protein C5 initiates assembly of the membrane attack complex. This remarkable process results in lysis of target cells and is fundamental to mammalian defense against infection. The 150-amino acid residue domain at the C terminus of C5 (C5-C345C) is pivotal to C5 function. It interacts with enzymes that convert C5 to C5b, the first step in the assembly of the membrane attack complex; it also binds to the membrane attack complex components C6 and C7 with high affinity. Here a recombinant version of this C5-C345C domain is shown to adopt the oligosaccharide/oligonucleotide binding fold, with two helices packed against a five-stranded beta-barrel. The structure is compared with those from the netrin-like module family that have a similar fold. Residues critical to the interaction with C5-convertase cluster on a mobile, hydrophobic inter-strand loop that protrudes from the open face of the beta-barrel. The opposite, helix-dominated face of C5-C345C carries a pair of exposed hydrophobic side chains adjacent to a striking negatively charged patch, consistent with affinity for positively charged factor I modules in C6 and C7. Modeling of homologous domains from complement proteins C3 and C4, which do not participate in membrane attack complex assembly, suggests that this provisionally identified C6/C7-interacting face is indeed specific to C5.

Rendering Deformable Surface Reflectance Fields

Animation of photorealistic computer graphics models is an important goal for many applications. Image-based modeling has emerged as a promising approach to capture and visualize real-world objects. Animating image-based models, however, is still a largely unsolved problem. In this paper, we extend a popular image-based representation called surface reflectance field to animate and render deformable real-world objects under arbitrary illumination. Deforming the surface reflectance field is achieved by modifying the underlying impostor geometry. We augment the impostor by a local parameterization that allows the correct evaluation of acquired reflectance images, preserving the original light model on the deformed surface. We present a deferred shading scheme to handle the increased amount of data involved in shading the deformable surface reflectance field. We show animations of various objects that were acquired with 3D photography.

3MATRIX and 3MOTIF: a protein structure visualization system for conserved sequence motifs.

Computational methods such as sequence alignment and motif construction are useful in grouping related proteins into families, as well as helping to annotate new proteins of unknown function. These methods identify conserved amino acids in protein sequences, but cannot determine the specific functional or structural roles of conserved amino acids without additional study. In this work, we present 3MATRIX (http://3matrix.stanford.edu) and 3MOTIF (http://3motif.stanford.edu), a web-based sequence motif visualization system that displays sequence motif information in its appropriate three-dimensional (3D) context. This system is flexible in that users can enter sequences, keywords, structures or sequence motifs to generate visualizations. In 3MOTIF, users can search using discrete sequence motifs such as PROSITE patterns, eMOTIFs, or any other regular expression-like motif. Similarly, 3MATRIX accepts an eMATRIX position-specific scoring matrix, or will convert a multiple sequence alignment block into an eMATRIX for visualization. Each query motif is used to search the protein structure database for matches, in which the motif is then visually highlighted in three dimensions. Important properties of motifs such as sequence conservation and solvent accessible surface area are also displayed in the visualizations, using carefully chosen color shading schemes.

3MOTIF: visualizing conserved protein sequence motifs in the protein structure database.

3MOTIF is a web application that visually maps conserved sequence motifs onto three-dimensional protein structures in the Protein Data Bank (PDB; Berman et al., Nucleic Acids Res., 28, 235-242, 2000). Important properties of motifs such as conservation strength and solvent accessible surface area at each position are visually represented on the structure using a variety of color shading schemes. Users can manipulate the displayed motifs using the freely available Chime plugin. http://motif.stanford.edu/3motif/

Recursive Estimation of Illuminant Motion from Flow Field and Simultaneous Recovery of Shape

We present a scheme based on the total least squares estimator to track the motion of a point source, by observing a sequence of images of an object illuminated by it. The initial shape of the object is estimated from any one of the existing shape and source from shading schemes from a single image frame. The total least squares formulation is used that considers this estimate of shape as being a noisy measurement of the actual shape. The method tracks the illuminant motion between successive frames from the flow field. Using the data only from two successive frames, an approach is developed to estimate the underlying illuminant motion between those two frames. This approach is then extended and a recursive method which uses the data from all previous image frames is developed to track the illuminant motion. An incremental shape recovery scheme using the proposed illuminant motion estimator is also presented. The method is then extended to deal with the presence of ambient light and the motion of multiple illuminants. We present typical simulation results to validate the proposed illuminant motion and shape update schemes. No feature point correspondence is required between the successive frames. Also the method is applicable to any general reflectance map.

Camptothecin production in Camptotheca acuminata seedlings in response to shading and flooding

One-year-old Camptotheca acuminata seedlings were grown under heavy shade (27% full sunlight), slight shade (67% full sunlight), or full sunlight for 2 weeks, then subjected to flooding for 4 weeks under continued shading schemes. Growth, chlorophyll fluorescence, and camptothecin concentrations were determined. Flooding led to significant decreases in leaf biomass, while shading significantly increased stem biomass. Under full sunlight or slight shade conditions, lateral root biomass was significantly decreased by flooding, whereas under heavy shade, it was not significantly reduced by flooding. Shaded leaves displayed significantly higher chlorophyll fluorescence than the non-shaded leaves throughout the 6-week period. Onset of flooding caused immediate decline of chlorophyll fluorescence of nonshaded and slight-shaded seedlings, but the effect of flooding quickly diminished. Heavy shade led to elevated camptothecin concentrations in leaves, whereas flooding had no effect. Camptothecin concentrations in stems were not altered by either flooding or shading; however, they were substantially lowered in lateral roots under heavy shade compared with those grown in full sunlight. Flooding induced an additional camptothecin accumulation in lateral roots under slight shade, but it failed to do so under either heavy shade or full sunlight conditions. Key words: anti-tumor compounds, camptothecin, chlorophyll fluorescence, flooding, secondary metabolites, shading.