nils-herrmann/clean_scirepeval huggingface dataset:
Joint rendering and segmentation of free-viewpoint images

This paper presents a method that jointly performs synthesis of free-viewpoint images and object segmentation from that viewpoint. This method works efficiently and online by sharing a certain calculation process among rendering and segmentation steps. Since the segmentation is performed for arbitrary viewpoints directly, the extracted object can be superimposed onto another 3-D scene with geometric consistency. Experimental results using a 25-camera array show the effectiveness of our method.
Unified environment-adaptive control of accompanying robots using artificial potential field

Our research is focused on mobile robots that can accompany a person, and this paper addresses how to control the relative position of the robot to the accompanied person according to the dynamic environment. The robot is expected to move side-by-side with the person in the normal situation, but the position in front or behind the person might be better if there are some obstacles. We devised the shape of the artificial potential field of the accompanied person to smoothly control the robot position in a unified way, and obtained favorable results via simulations.
A novel small-capacity photovoltaic module for mobile applications

We propose a new small-capacity photovoltaic module with a booster function from ultra low voltage input, low power consumption maximum power point tracking (MPPT) and power System-in-Package (SiP) technology for mobile applications. The ultra low voltage input booster function enable single solar cell application without a series connection of solar cell to drive the device and /or charging the battery. This function solves the problem of partial shading of the small capacity photovoltaic module. Low-power-consumption MPPT is achieved by using a newly developed boost control IC. The MPPT can draw 1.2 to 1.5 times more power from the photovoltaic module than can be drawn without MPPT. Moreover, in cloud condition this circuit can get over 1.5 times more power than without MPPT. The main feature of the circuit is raising up output voltage to 15 V from a single solar cell 0.4 V. The power SiP, contains three semiconductor devices and several tenth of passive parts to minimize the size and improve efficiency.
Rate-distortion analysis of super-resolution image/video decoding

An image/video communication scenario with super-resolution (SR) decoding, where the decoded images are upsampled using SR reconstruction at the receiver side, is analyzed from a theoretical perspective. To formulate the rate-distortion performance for such cases, we propose a new numerical model that combines a frequency-domain SR model and a rate-distortion theory for lossy image compression. We considered several factors that affect the reconstruction quality, and revealed that SR decoding performs better in low bitrates. We also conducted real-image simulations and confirmed that both the numerical analysis and real-image simulations exhibit quite similar tendencies, which supports the effectiveness of our numerical model.
TransCAIP: A Live 3D TV System Using a Camera Array and an Integral Photography Display with Interactive Control of Viewing Parameters

The system described in this paper provides a real-time 3D visual experience by using an array of 64 video cameras and an integral photography display with 60 viewing directions. The live 3D scene in front of the camera array is reproduced by the full-color, full-parallax autostereoscopic display with interactive control of viewing parameters. The main technical challenge is fast and flexible conversion of the data from the 64 multicamera images to the integral photography format. Based on image-based rendering techniques, our conversion method first renders 60 novel images corresponding to the viewing directions of the display, and then arranges the rendered pixels to produce an integral photography image. For real-time processing on a single PC, all the conversion processes are implemented on a GPU with GPGPU techniques. The conversion method also allows a user to interactively control viewing parameters of the displayed image for reproducing the dynamic 3D scene with desirable parameters. This control is performed as a software process, without reconfiguring the hardware system, by changing the rendering parameters such as the convergence point of the rendering cameras and the interval between the viewpoints of the rendering cameras.
Bandwidth-guaranteed video delivery system employing new ethernet synchronization method

Optical-fiber communication systems have been adopted to deliver video data at high bit rates for professional use. In such professional video delivery systems, each broadcast station needs to edit video data and this requires frequency clock synchronization between broadcast stations. For synchronization, a synchronous network such as ATM (Asynchronous Transfer Mode) was adopted into video delivery systems for traditional professional use. In order to achieve a sufficient guaranteed bandwidth and low packet delay variation using Ethernet, we propose a new transmission frame that consists of fix-sized Ethernet packets and a fixed-sized inter-frame gap (IFG). Furthermore, we propose applying a new synchronization method that monitors the change in the IFG length. Test results on the proposed method show that the synchronization accuracy is &#60; 0.1 ppm.
Modal Bandwidth Enhancement of Plastic Optical Fibers by W-Shaped Refractive Index Profile

Modal bandwidth enhancement in multimode plastic optical fibers (POFs) is successfully achieved by a W-shaped refractive index profile, even compared to conventional high-bandwidth graded-index (GI) POFs. We experimentally fabricate different types of W-shaped POFs by varying the index exponent g, numerical aperture, and depth of the index valley. Then, we verify that the group delay of high-order modes is strongly affected by the index valley, by which the bandwidth higher than that of conventional GI POFs is achieved. In this paper, we design the optimum index profile of W-shaped POF for high-bandwidth performance. In addition to the bandwidth enhancement, we demonstrate low bending-loss in W-shaped POFs compared to GI POFs.
Theoretical analysis on interframe predictive coding with subpixel displacement accuracy — An exhaustive approach

A theoretical analysis on interframe predictive coding is presented in which special attention is paid on two issues that are practically important. First, the displacements between the target and reference images are usually given with limited accuracy due to quantization. Second, when the displacements are provided in subpixel accuracies, interpolation between the pixels is necessary to produce an estimation image. Our formulation takes an exhaustive approach in which we faithfully follow the process of subpixel interpolations with limited displacement accuracies. Our analysis can be used to determine how accurate the displacement vectors should be and which subpixel interpolation method should be used to optimize the rate-distortion performance.
PCA-coded aperture for light field photography

A light field, which is often understood as a set of dense multi-view images, has been utilized in various 2D/3D applications. Efficient light field acquisition using a coded aperture camera is the target problem considered in this paper. Specifically, the entire light field, which consists of many images, should be reconstructed from only a few images that are captured through different aperture patterns. In previous work, this problem has often been discussed from the context of compressed sensing (CS). In contrast, we formulated this problem from the perspective of principal component analysis (PCA) to derive optimal non-negative aperture patterns and a straight-forward reconstruction algorithm. Even though it is based on a conventional technique, our method has proven to be more accurate and much faster than a state-of-the-art CS-based method.
Theoretical Analysis of View Interpolation With Inaccurate Depth Information

A problem of view interpolation from a pair of rectified stereo images with inaccurate depth information is addressed. Errors in geometric information greatly affect the quality of the resulting images since inaccurate geometry causes miscorrespondences between the input images. A new theory for quantitatively analyzing the effect of depth errors and providing a principled optimization scheme based on the mean-squared error metric is proposed. The theory clarifies that, if the probabilistic distribution of the depth errors is given, an optimized view-interpolation scheme that outperforms conventional linear interpolation can be derived. It also reveals that, under specific conditions, linear interpolation is acceptable as an approximation of the optimized-interpolation scheme. Furthermore, band limitation combined with linear interpolation is also analyzed, leading to an optimal cutoff frequency, which achieves better results than the antialias scheme proposed in previous studies. Experimental results using real scenes are also presented to confirm this theory.
A 0.9 V operation 2-transistor flash memory for embedded logic LSIs

A novel 2-transistor flash memory cell is proposed to meet the read performance of mask ROMs. A very low 0.9 V nonword-line-boosting read operation is successfully achieved by employing a novel 2-transistor channel F-N program and channel F-N erase NOR (2-Tr CCNOR) flash memory architecture. We realize a low power program/erase scheme and high reliability by utilizing hole-free channel F-N tunneling with a simple memory cell structure and process.
Multi-Pole Components of Magnetic Field in Dipole Magnets Wound With High $T_{\rm c}$ Superconductor Tape and Feasibility of Their Accelerator Applications

Applications of high superconductors to accelerator magnets are attractive from the viewpoint of cooling cost reduction and that of generating very high magnetic field at low temperature. However, in magnets using cosine-theta like coils, three-dimensional shape of coil ends and magnetic field quality might be concerns, because most of practical high superconductors are with flat tape shape. We studied the field quality of dipole magnets wound with high superconductor tapes. Case studies on magnetic field design were made for dipole magnets wound with coated conductors: we designed two magnets and calculated multi-pole components of the magnetic field to evaluate their field qualities. The torsion/bending tolerance of coated conductors was studied experimentally to clarify the feasibility of three-dimensional winding. The influence of the shielding current in high superconductor tapes on field quality was discussed based on the numerical electromagnetic field analysis of superconductors.
Pulsed-Field Magnetizing Characteristics of Rectangular-Shaped Gd–Ba–Cu–O Bulk Using Split- and Solenoid-Type Coils

We have investigated the trapped-held characteristics of a rectangular-shaped Gd-Ba-Cu-O bulk (33 × 33 × 15 mm3) magnetized by pulsed-field magnetization (PFM) using split- and solenoid-type coils. A soft iron yoke was set below the bulk for the solenoid coil and two yokes are inserted in the bores of the split coil. The maximum trapped held BZmax at the center of the bulk surface was 1.73 T at 40 K in the case of the solenoid coil, with a distorted profile. On the other hand BZmax was enhanced to 3.05 T at 40 K for the split coil with two yokes for which a symmetric trapped-held profile was observed. The behavior of the magnetic flux motion indicated two conditions for the enhancement of the trapped held: that the magnetic flux intrudes easily into the bulk even for lower applied fields and then saturates with minimal flux creep. We have also investigated the electromagnetic and thermal properties of the bulk during PFM using a numerical simulation in which the magnetic flux tended to align along the z-axis due to the presence of the soft iron yoke. The use of the split coil with two yokes is effective in enhancing the trapped held for the rectangular-shaped bulks.
Unstructured light field rendering using on-the-fly focus measurement

This paper introduces a novel image-based rendering method which uses inputs from unstructured cameras and synthesizes free-viewpoint images of high quality. Our method uses a set of depth layers in order to deal with scenes with large depth ranges. To each pixel on the synthesized image, the optimal depth layer is assigned automatically based on the on-the-fly focus measurement algorithm that we propose. We implemented this method efficiently on a PC and achieved nearly interactive frame-rates.
Rate-distortion performance of multi-view image coding with subsampling of viewpoints

In this paper, we consider the rate-distortion performance of a multi- view image set with subsampling of the viewpoints. As a basic analysis, we compare two scenarios: (i) all images would be coded and transmitted in even quality, and (ii) a half of the images would be discarded by subsampling at the sender side, and the remaining half would be coded and transmitted. In the second scenario, the discarded images would be reconstructed at the receiver side using some view interpolation technology. We first introduce a theoretical model describing the rate-distortion performance of the scenarios above. Then, we present numerical simulations and experiments, showing that which scenario yields better performance depends on the bitrate, the properties of the image set, and the accuracy of the view interpolation.
Direction-adaptive hierarchical decomposition for image coding

A new model of decomposing an image hierarchically into direction-adaptive subbands using pixel-wise direction estimation is presented. For each decomposing operation, an input image is divided into two parts: a base image subsampled from the input image and subband components. The subband components consist of residuals of estimating the pixels skipped through the subsampling, which ensures the invertibility of the decomposition. The estimation is performed in a direction-adaptive way, whose optimal direction is determined by a L1 norm criterion for each pixel, aiming to achieve good energy compaction that is suitable for image coding. Furthermore, since the L1 norms are obtained from the base image alone, we do not need to retain the directional information explicitly, which is another advantage of our model. Experimental results show that the proposed model can achieve lower entropy than conventional Haar or D5/3 discrete wavelet transform in case of lossless coding.
Online segmentation of free-viewpoint video

This paper presents a method that jointly performs synthesis and object segmentation of free-viewpoint video using multi-view video as the input. This method works efficiently and online by sharing 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 3-D 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. Experimental results using a 25-camera array show the effectiveness of our method.
Real-time view synthesis system using active illumination and adaptive space-time cost-volume filtering

Our target is development of a view synthesis system that includes the entire process from capturing of multi-view videos to synthesize virtual view in real-time. Depth estimation of the target scene is indispensable for view synthesis from multi-view videos. In this paper, we improved the depth estimation method we had developed in a previous work, where an active illumination technique was combined with an efficient layer based algorithm. More specifically, we proposed an adaptive space-time filtering for the cost volumes constructed for depth estimation. The adaptive space-time filtering adapts its shape for each pixel automatically according for depth estimation, resulting in higher quality of the depth estimation especially in dynamic scenes. Our method was tested on a system consisting of 16 video cameras and a Digital Light Processing (DLP) projector to show its effectiveness. We achieved higher quality depth estimation, resulting in higher quality virtual view synthesis with a nearly real-time frame rate.
Toward Optimization of Multi-Pulse, Pulsed Field Magnetization of Bulk High-Temperature Superconductors

Pulsed field magnetization (PFM) is the most practical method for magnetizing bulk superconducting materials as trapped field magnets, but the record trapped field achieved by PFM to date is still significantly less than the true trapped field capability of these materials. In this paper, a flexible numerical modeling technique based on the finite element method is used to provide a comprehensive and realistic picture of multi-pulse PFM, which has been shown to be effective in increasing the trapped field/flux over a single pulse. First, the maximum trapped field capability of a representative sample is determined using two types of numerical model simulating field-cooling and zero-field-cooling magnetization. Next, various sets of magnetic field pulses are applied to the bulk to analyze multi-pulse PFM. An increase in the trapped field can be achieved after a second pulse and to do so an increased amplitude of applied field is required to maximize the trapped field fully. The numerical analysis shows that this occurs in subsequent pulses because it is more difficult for the magnetic flux to penetrate the sample and there is a lower temperature rise.
Modal bandwidth enhancement in a plastic optical fiber by W-refractive index profile

A plastic optical fiber (POF) having a W-shaped refractive index profile (W-shaped POF) was prepared for the first time that had a possibility to realize a higher bit rate transmission than those of the conventional silica-based multimode fiber and graded index (GI) POF links. Since the W-shaped POF has a valley of the refractive index at the boundary of the core and cladding of the conventional graded-index (GI) POF, the group delay of higher order modes is strongly influenced, and the modal dispersion in the GI POF is compensated. By comparing the propagating mode properties of the W-shaped POF with those of the GI POF, we clarified theoretically and experimentally that the index valley has a remarkable modal dispersion compensation effect.
Spatial domain analysis on the focus measurement for light field rendering

Light field rendering (LFR) is an image-based rendering method for synthesizing free-viewpoint images from a set of multi-view images. In LFR, no/little knowledge of geometry is required, since scene objects are assumed to be at a constant depth. This assumption causes focus-like effects on synthetic images, in which only the objects near to the assumed depth are synthesized clearly and sharply. In order to generate all-in-focus synthetic images, the authors proposed a focus measurement method which uses several kinds of reconstruction filters. Using this method, we can detect in-focus parts on multiple images that are synthesized with different assumed depths, and integrate them into one final image. Though this algorithm was shown to be effective for some real scenes, the optimal combination of reconstruction filters has not been discussed yet. In this paper, we introduce a detailed spatial domain analysis of this focus measurement method, and compare three combinations by the theoretical analysis and an experiment.
Displaying Real-World Light Fields With Stacked Multiplicative Layers: Requirement and Data Conversion for Input Multiview Images

To provide realistic 3-D perception to human observers, 3-D displays have evolved to present not only a pair of stereo images but also many images to different viewing directions. A light-field display, which consists of a few light-attenuating pixelized layers (e.g., LCD panels) stacked in front of a backlight, has attracted attention because of its potential to simultaneously support many viewing directions with high quality. The transmittances of the layers are determined from a set of multiview images or a light field that is given to represent observations expected from many viewing directions. However, the relation between the configuration of the given light field and the quality of displayed images has not sufficiently been discussed in previous works. In this study, in our aim to display real-world objects with high quality, we address the requirement for the target light field given as the input. We deeply analyze several factors that associate the configuration of the target light field with the quality of the displayed images, and we derive a quantitative requirement on the configuration: The disparities among the adjacent viewpoints should be limited to 0-1 pixels. To meet this strict requirement with real-world objects, we propose using a multiview camera and image-based rendering, where we can generate virtual light fields with arbitrary configurations and densities. Our theory and method are verified by experiments using a computer-simulated display.
Simulation of shielding performance against near field coupling to EMI filter for power electronic converter using FEM

When designing an Electromagnetic interference (EMI) filter for power electronic converters, we should consider the shielding performance against the external near field coupling to the EMI filter as well as the attenuation performance. In this paper, we studied the validity of the Finite Element Method (FEM) simulation of the EMI filter for predicting the shielding performance before a trial manufacture. First, we created models of capacitors and common mode choke coils which can simulate their impedance characteristics. Next, using these component models, the assembled EMI filter model was created. We compared the measured and simulated results to verify the model. The shielding performance was evaluated using a loop coil as an external near field source. Consequently, the simulated results agreed with the measured results well.
Synthesis Error COmpeNsateD Multiview Video plus Depth for representation of multiview video

SECOND-MVD (Synthesis Error COmpeNsateD Multiview Video plus Depth) is an alternative 3D format that we introduce for representation of multiview video. In this data format, images at some viewpoint remain original, and the others are converted to a novel format. Residual based representation, such as layered depth video and free-viewpoint TV data unit were proposed. We propose hybrid image that not only consists of residual but also remainder pixels. Generation and reconstruction process of a hybrid image uses virtual image synthesized by the images that remained original in SECOND-MVD. In this paper, we investigate the compression performance of SECOND-MVD using hybrid image. Experiments demonstrate reduction in bit rate using hybrid image against residual image in SECOND-MVD framework.
Depth of field in light field rendering

This paper focuses on the sampling problem in light field rendering (LFR) that is a fundamental approach to image based rendering. Quality of LFR depends on a light ray database generated from pre-acquired images, since image synthesis is a process of gathering appropriate light ray data from the database. For improving the quality, interpolation of light ray data is effective. It is based on an assumption that scene objects are placed on a plane called "focal plane". According to the depth of the focal plane (distance between cameras and focal plane), focus-like effect would appear on the synthesized images. In this paper, we formulate the depth of field In light field rendering to address the range of depth where scene objects are rendered in focus. In our theory, the plenoptic sampling theory is generalized to compare with some other related works. Our representation is intuitive and useful for quantitative analysis of LFR.