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The vector graphics with gradient mesh can be attributed to their compactness and scalability; however, they tend to fall short when it comes to real-time editing due to a lack of real-time rasterization and an efficient editing tool for image details. In this paper, we encode global manipulation geometries and local image details within a hybrid vector structure, using parametric patches and detailed features for localized and parallelized thin-plate spline interpolation in order to achieve good compressibility, interactive expressibility, and editability. The proposed system then automatically extracts an optimal set of detailed color features while considering the compression ratio of the image as well as reconstruction error and its characteristics applicable to the preservation of structural and irregular saliency of the image. The proposed real-time vector representation makes it possible to construct an interactive editing system for detail-maintained image magnification and color editing as well as material replacement in cross mapping, without maintaining spatial and temporal consistency while editing in a raster space. Experiments demonstrate that our representation method is superior to several state-of-the-art methods and as good as JPEG, while providing real-time editability and preserving structural and irregular saliency information.

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.

We report on the analysis of quantum transport through an Aharonov-Bohm ring with embedded double quantum dots. The normal metal leads are assumed to be weakly coupled to the two quantum dots. In the quantum dot region, Rashba spin-orbit coupling and electron-electron interaction are considered. The quantum transport is analyzed based on the Keldysh nonequilibrium Green's function formalism. A spin-polarized current emerges in this device due to the combined effect of a magnetic flux, threading through the AB ring, and the Rashba spin-orbit coupling. An interesting switching property of the spin polarization by turning on and off the gate within small voltage window is observed. This feature, however, does not exist in the Aharonov-Bohm ring structure with single quantum dot. We therefore propose a theoretical idea of a bipolar spin polarization switch

Orthogonal frequency-division multiplexing (OFDM) signaling format is commonly associated with guard subintervals to reject interblock interference (IBI) and enable simple one-tap frequency-domain equalization (FDE) at the receiver when received over dispersive channels. Despite the advantages, the insertion of guard subintervals expands the signal spectrum and thus trades off the spectral efficiency significantly. In this paper, the nonguarded OFDM (NG-OFDM) signaling format, which is exactly OFDM without inserting guard subintervals, is considered to avoid the spectrum expansion and combined with spectral precoding to further achieve high spectrum compactness. In particular, spectral precoders are designed for NG-OFDM to provide very small spectral sidelobes, and thus extremely compact signal spectrum, and associate the transmitted waveform with low peak-to-average power ratio. To reject IBI among received NG-OFDM blocks over dispersive channels, a guard subinterval in each received block is removed at the receiver, and this turns the resultant receiver as nonorthogonal over subcarrier subchannels, thus resulting in intercarrier interference (ICI). The corresponding channel capacity and linear minimum-mean-square-error (LMMSE) data estimation are analyzed. It is shown that the proposed spectrally precoded NG-OFDM (SP-NG-OFDM) system can provide channel capacity very close to nonprecoded and spectrally precoded OFDM using the cyclic prefix (CP-OFDM) when the removal guard ratio is small, and much higher channel capacity per unit bandwidth than spectrally precoded CP-OFDM conveying the same data rate provided that a small out-of-band power proportion is required. When a sufficiently small precoding rate is adopted, the SP-NG-OFDM receiver, using guard removal and LMMSE-FDE, is also shown to counteract ICI effectively and exploit frequency diversity over dispersive channels.

This paper is concerned with minimizing the delay due to data communication during the execution of a parallel algorithm on an SIMD computer with a two-way circular unit-shift interconnection network. Algorithms are developed which determine, for a given parallel procedure, the order of computation within that procedure, for every parallel arithmetic expression, the alignment of operands for every binary operation, and the mapping and remapping of data into physical memories so that the communication cost is minimized. The proposed algorithms are applicable to array variables with special types of index functions.