nils-herrmann/clean_scirepeval huggingface dataset:
Interactive viewpoint-space navigation for visual-audio exhibition of painting

In this paper, we present a system for exhibiting a Chinese landscape painting about 900 years old. There are three parts in our system: (1) we allocate a voice dubbing or background music, which is treated as a point sound source, onto the 2D painting and obtain its position in the 2D space. All of the audio data are then located in a 3D hidden space, by projecting their 2D positions to the 3D space through a projection model. (2) A two-layer directed graph structure is proposed to well organize the audio data in a 4D space (with 1D temporal and 3D spatial). (3) The exhibition is defined as an active exploration in a viewpoint space, which faces both the image and the 3D world where the sound sources reside. The 3D space and the two-layer graph structure generate a natural and meaningful stereo audio field. Meanwhile, compared to videos with guided walk through, the active exploration makes the exhibition more attractive.
Adaptive subcarrier and power allocation for delivering fine granularity scalable video stream over OFDMA system

In this paper, an adaptive subcarrier and power allocation algorithm is proposed for delivering fine granularity scalable (FGS) video stream over an OFDMA system. The proposed method targets, does not only minimize the overall transmission errors, but also provide the similar visual quality in the mean-square error sense to all users at a power constraint. The transmission optimization based on rate distortion theory is developed to achieve such a goal, which is implemented in two steps. First, assignment of layers to subcarriers is performed to achieve the maximum power efficiency, and secondly, optimal power distribution across all subcarriers is performed. The simulated results show that, compared to the uniform subcarrier and power allocation scheme, the proposed algorithm can achieve significant performance improvement in terms of both the overall transmission efficiency and the impartially quality division to each user.
An Alternative Method for Power System Dynamic State Estimation Based on Unscented Transform

An efficient, timely, and accurate state estimation is a prerequisite for most energy management system (EMS) applications in power system control centers. The emerging wide-area measurement systems (WAMSs) offer new opportunities for developing more effective methods to monitor power system dynamics online. Recently, alternative methods for power system state estimation have caught much attention. Due to the nonlinearity of state transition and observation equation, linearization and Jacobian matrix calculation are indispensible in the existing methods of power system state estimation. This makes WAMS' high performance compromised by burdensome calculation. In order to overcome the drawbacks, this study tries to develop an effective state estimation method without the linearization and Jacobian matrix calculation. Firstly, unscented transformation is introduced as an effective method to calculate the means and covariances of a random vector undergoing a nonlinear transformation. Secondly, by embedding the unscented transformation into the Kalman filter process, a method is developed for power system dynamic state estimation. Finally, some simulation results are presented showing accuracy and easier implementation of the new method.
A Description Method for Network Architecture

Due to lack of desired model for traditional network architecture, services which are newly deployed can't be analyzed and verified quickly or efficiently. To address this problem, this paper puts forward a description method for network architectures which includes two parts: the modeling method and the formal model. First of all, we give a modeling method from the essence of the service interactions for network architecture, secondly, on the base of the modeling method, the formal model which is a description method for network architecture is provided, finally, we provide an application case with the description method. It is verified that the description method does well in the description of the network architectures and it can satisfy the need of analyzing the deploying of new services.
Demultiplexer design for multi-edge type LDPC coded modulation

Generally, the capacity-achieving signaling design for a specific channel should consider the joint optimization of channel coding and modulation. Nevertheless, coding theorists and practitioners have recognized that a well-designed LDPC code can achieve capacity-approaching performance universally across a range of data transmission and storage channels. A pronounced example is the forward error correction scheme adopted recently by the second generation standards for digital video broadcasting (DVB), wherein the same LDPC codes are expected to be reused over satellite, terrestrial and cable channels. However, to accommodate the spectral efficiency of different channel type, the coded bits should be mapped to the modulator judiciously. The well-known BICM strategy employs a large random bit interleaver, which typically yields good performance for an arbitrary choice of constellation mapper. However, it is problematic for high-speed coding and modulation due to the large amount of memory and circuits routing required. This motivates us to impose structural simplicity on the bit interleaver configuration so that the coded bits are de-multiplexed systematically into parallel groups to feed the constellation mapper. In this paper, we focus on the design of bit demultiplexers for multi-level modulations by applying the framework of multi-edge type (MET) LDPC. Since the channel-dependence of a given code ensemble is dominated by the mutual information between the input and output of the effective channel, we propose to simplify the analysis of the decoding behavior by using a set of surrogate binary erasure channels (BEC). Simulation results indicate that the proposed bit demultiplexer surpasses the performance of the heuristic interleaving strategy specified in second generation DVB standard for terrestrial channels (DVB-T2).
Investigation of disc-type sensors using the UHF method to detect partial discharge in GIS

The disc-type UHF sensor is considered among the simplest couplers for partial discharge (PD) detection in gas-insulated switchgear (GIS). This paper mainly focuses on the improvement of the sensitivity of the disc-type sensor. Disc-type sensors with different dimensions were tested on a 220 kV model GIS to find the critical parameters that determine the sensitivity of the sensor. The waveform of the PD signal and the twoport insertion loss were measured to see the amplitude of the output signal and the transmission rate on different frequencies. The FD-TD method was used to investigate the dimension factors in detail along with the effect of the dimension of the tank in which the sensors are installed. The transformation process between the TEM mode and the higher-order modes of the electromagnetic (EM) wave was also simulated to investigate the receiving efficiency of the disc-type sensors for different propagation modes. The results showed that the diameter of the disc and the ratio of the height of the disc to the thickness of the insulation were the most critical parameters that determined the sensitivity of the disc-type sensor.
Multi layer based rate control algorithm for HEVC

The specialized QP determination and reference picture set (RPS) mechanism in High Efficiency Video Coding (HEVC) significantly improves the coding efficiency. In this paper, we propose a frame layer rate control algorithm for HEVC based on this specialized mechanism. Firstly, we design a RPS based hierarchical partition structure. Then an efficient hierarchical bit allocation scheme is proposed. Moreover, a novel header bits ratio prediction method is also provided to further improve the accuracy of bit allocation. Finally, an improved mean of absolute difference (MAD) prediction scheme is provided for quadratic R-Q model to calculate an accurate quantization parameter. Experimental results demonstrate the proposed algorithm has much better R-D performance. Compared with the state-of-the-art rate control scheme for HEVC, the BD-Rate gain can be up to 30% and BD-PSNR gain can be 0.6dB on average in Low_Delay configuration. Moreover, our proposed algorithm also provides smaller mismatch between the target bit rate and the actual bit rate.
Local Gabor Binary Patterns Based on Kullback–Leibler Divergence for Partially Occluded Face Recognition

The partial occlusion is one of the key issues in the face recognition community. To resolve the problem of partial occlusion, based on our previous work of local Gabor binary patterns (LGBP) for face recognition, we further propose Kullback-Leibler divergence (KLD)-based LGBP for partial occluded face recognition. The local property of LGBP face recognition is thoroughly used in the method, by introducing KLD between the LGBP feature of the local region and that of the non-occluded local region to estimate the probability of occlusion. The probability is used as the weight of the local region for the final feature matching. The experimental results on the AR face database demonstrate the effectiveness of the KLD-based LGBP face recognition method for partially occluded face images.
Decoupled control of doubly fed induction generator for wind power system

Wind power, as an important and promising renewable resource, is widely studied. Recently, doubly fed induction generator (DFIG) becomes more popular in wind power due to its various advantages over other types of wind turbines, such as variable speed, lower power electronic cost and so on. However, the back-to-back converters require effective and accurate control to accommodate the complexity of power system operation. In this paper, first of all, a dynamic model of DFIG-based wind power system is derived in complex form. Based on the dynamic model, a complete control strategy is presented to control the rotor-side converter and grid-side converter, respectively. A decoupled control method, which is capable of separating d-axis and q-axis components of rotor current, is applied to harness wind power. The concept of instantaneous power is introduced to regulate DC-link voltage. The control strategy is tested in RTDS/RSCAD. The effectiveness of the proposed method is verified by the simulation results.
Low voltage ride-through and performance improvement of a grid connected DFIG system

In this paper, analytical study on the impact of voltage sag in the internal dynamics of a grid connected Doubly Fed Induction Generator (DFIG) system is presented. A common dc-link of the rotor side converter (RSC) and grid side converter (GSC) supported static compensator (STATCOM) is proposed for the voltage ride through capability. The proposed system is connected to a small transmission network, where many types' loads are connected. It is observed that the voltage sag at the PCC of the grid affects the internal dynamics of DFIG such as flux demagnetization of the stator flux, high transients in the developed electromagnetic torque, and abnormal rotor current spikes. This affects the performance of the DFIG during transient conditions and this may leads to the malfunctioning of the power electronics converters. This topology will also support the reactive power requirement of the grid without affecting the performance of the dc-link voltage. Hence, this structure is useful in improving the transient stability, power oscillation damping, voltage stability and increase in power transfer limit of the connected power system. The proposed DFIG system along with its controller is modeled and simulated in MATLAB using Simulink and power system block-set toolboxes. The simulation results are presented to validate the performance of the proposed system.
Comparison and review of islanding detection techniques for distributed energy resources

The many different islanding detection methods for anti-islanding protection in power system are discussed. Passive, active and remote techniques are reviewed. Most of the ldquoactive methodsrdquo discussed are developed for photovoltaic (PV) as a distributed energy resource. Some recent methods can be use for any type of distributed generation. A final comparison of active islanding detection methods is presented later in this paper.
Just-Noticeable Difference-Based Perceptual Optimization for JPEG Compression

The Quantization table in JPEG, which specifies the quantization scale for each discrete cosine transform (DCT) coefficient, plays an important role in image codec optimization. However, the generic quantization table design that is based on the characteristics of human visual system (HVS) cannot adapt to the variations of image content. In this letter, we propose a just-noticeable difference (JND) based quantization table derivation method for JPEG by optimizing the rate-distortion costs for all the frequency bands. To achieve better perceptual quality, the DCT domain JND-based distortion metric is utilized to model the stair distortion perceived by HVS. The rate-distortion cost for each band is derived by estimating the rate with the first-order entropy of quantized coefficients. Subsequently, the optimal quantization table is obtained by minimizing the total rate-distortion costs of all the bands. Extensive experimental results show that the quantization table generated by the proposed method achieves significant bit-rate savings compared with JPEG recommended quantization table and specifically developed quantization tables in terms of both objective and subjective evaluations.
Depth-Preserving Warping for Stereo Image Retargeting

The popularity of stereo images and various display devices poses the need of stereo image retargeting techniques. Existing warping-based retargeting methods can well preserve the shape of salient objects in a retargeted stereo image pair. Nevertheless, these methods often incur depth distortion, since they attempt to preserve depth by maintaining the disparity of a set of sparse correspondences, rather than directly controlling the warping. In this paper, by considering how to directly control the warping functions, we propose a warping-based stereo image retargeting approach that can simultaneously preserve the shape of salient objects and the depth of 3D scenes. We first characterize the depth distortion in terms of warping functions to investigate the impact of a warping function on depth distortion. Based on the depth distortion model, we then exploit binocular visual characteristics of stereo images to derive region-based depth-preserving constraints which directly control the warping functions so as to faithfully preserve the depth of 3D scenes. Third, with the region-based depth-preserving constraints, we present a novel warping-based stereo image retargeting framework. Since the depth-preserving constraints are derived regardless of shape preservation, we relax the depth-preserving constraints to fulfill a tradeoff between shape preservation and depth preservation. Finally, we propose a quad-based implementation of the proposed framework. The results demonstrate the efficacy of our method in both depth and shape preservation for stereo image retargeting.
An experimental environment for studying hybrid fuel cell system operating characteristics

Fuel Cell/Battery hybrid systems represent a major technology solution for future vehicles, portable auxiliary power supplies, and distributed generation. Today's focus on clean and renewable energy has sparked interests in fuel cell systems, especially the hydrogen PEM fuel cell (FC). Past and current research states that fuel cells cannot effectively handle dynamic loads on their own and thus a battery bank can be used to provide the power for varying load currents. This paper seeks to demonstrate the concept of the fuel cell-battery hybrid system by showing the operating characteristics of a system driven only by a FC and as a hybrid in an experimental environment. The dynamic load consists of a tandem DC motor drive and generator set. This set provides various load profiles such as variable motor speeds and constant motor drive speeds with variable electric generator loads. The 50 Watt Hampden model H-FCTT-1 is used in our experiments for studying the differences of fuel cell operating characteristics in non-hybrid and hybrid systems.
A Real-Time Video Watermarking Using Adjacent Luminance Blocks Correlation Based on Compressed Domain

Based on the strong correlation of adjacent luminance blocks, this paper proposes a video watermarking algorithm based on the correlation of adjacent luminance blocks in the MPEG-4 video coding standard bit-stream. In the algorithm, the watermark is embedded in the DCT coefficients of I frames and P frames. This algorithm adopts the re-embedding and optimal retrieving strategy to guarantee the synchronization between embedding and retrieving watermark, and improve the robustness of watermarking. Experimental results show that this algorithm has obvious low complexity, high watermark payload and the strong robustness against re-encoding, multiple re-encoding and deleting.
Adaptive transform with HEVC intra coding

This paper proposes a content adaptive transform based on singular value decomposition (SVD) with HEVC intra coding. In the latest video coding standard HEVC, a combination of Discrete Cosine Transform (DCT) and Discrete Sine Transform (DST) is adopted to transform the residuals from intra prediction. The DCT and DST are fixed transforms which are derived based on the Gauss-Markov model. Since the residual blocks contain various distributions which may not be compacted well by the fixed DCT/DST, we propose an adaptive transform method based on SVD which is adaptive to residuals for angular intra coding. Experimental results show that the proposed method can achieve rate-distortion performance improvements compared to HEVC intra coding (up to 1.9% bit rate savings).
An efficient VLSI architecture of VLD for AVS HDTV decoder

In this paper, we present a VLSI design of variable length code decoder for AVS video standard. As a co-processor of a RISC CPU, the design can decode fixed length code, unsigned or signed k-th Exp-Golomb code, and AVS 2-D variable length code. Furthermore, it has a pre-processing submodule, which can perform start code detection and de-stuffing for the input bitstream. The proposed architecture has been described in Verilog HDL, simulated with VCS digital simulator, and implemented using 0.18 /spl mu/ Artisan CMOS cells library by synopsys design compiler. The circuit costs about 15k equivalent logic gates (not including 4 kb on-chip SRAM). And the critical path is less than 6 ns in the worst case. This design has been implemented in a single chip AVS HDTV decoder, AVS101, which can support real-time decoding for NTSC, PAL, 720p 60 frames/s or 1080i 60 fields/s programs. Although the architecture was originally designed for AVS video standard, it can be easily adapted to other coding standards.
Discriminant analysis for perceptionally comparable classes

Traditional discriminate analysis treats all the involved classes equally in the computation of the between-class scatter matrix. However, we find that for many vision tasks, the classes to be processed are not equal in perception, i.e. a distance metric can be defined between the classes. Typical examples include head pose classification and age estimation. Aiming at this category of classification problem, this paper proposes a novel discriminant analysis method, called Class Distance based Discriminant Analysis (CDDA). In CDDA, the perceptional distance between two classes is exploited to weight the outer product in the between-class scatter computation, to concentrate more on the classes difficult to separate. Another novelty of CDDA is that to preserve the within-class local structure of multimodal labeled data, the within-class scatter is re-defined by complementing the similarity of the samples pairs in the nearby classes. The method is then applied to head pose classification and age estimation problem, and experimental results demonstrate the effectiveness of CDDA.
Locating partial discharge in power transformer by electrical method

To locale partial discharge (PD) source in power transformer by electrical method, the propagating principle of PD pulse along transformer windings and the response of PD pulse at detecting terminals outside the transformer are studied. Simulating analysis through numerical model and imitating experiment on transformer winding are carried out. A simulation model of transformer winding is established. The equivalent circuit is made-up in order that the transfer property of PD pulse along the winding could be calculated and analyzed. There are differences in the properties according to the PD source positions so that the relationship between the difference and PD positions can provide some information for PD locating. Based on numerical treatment of the relationship, the electrical method of PD locating is presented. The energy of the measured signal is used to locale PD source. The device for PD pulse imitating is developed for the experiments on transformer windings. The terminal signals caused by PDs at different positions are measured during the experiments, and the results indicate that the locating accuracy of these methods is satisfied for engineering practice use.
Macro-Block-Level Selective Background Difference Coding for Surveillance Video

Utilizing the special properties to improve the surveillance video coding efficiency still has much room, although there have been three typical paradigms of methods: object-oriented, background-prediction-based and background-difference-based methods. However, due to the inaccurate foreground segmentation, the low-quality or unclear background frame, and the potential "foreground pollution" phenomenon, there is still much room for improvement. To address this problem, this paper proposes a macro-block-level selective background difference coding method (MSBDC). MSBDC selects the following two ways to encode each macro-block (MB): coding the original MB, and directly coding the difference data between the MB and its corresponding background. MSBDC also features at employs the classification of MBs to facilitate the selection, through which, prediction and motion compensation turns more accurate, both on foreground and background. Results show that, MSBDC significantly decreases the total bitrate and obtains a remarkable performance gain on foreground compared with several state-of-the-art methods.
MPEG Internet Video Coding Standard and Its Performance Evaluation

MPEG has produced standards that have provided the industry with the best video compression technologies. To address diverse Internet needs, MPEG issued a Call for Proposals (CfP) for Internet video coding (IVC) in July, 2011. The anticipation is that any patent declaration associated with the baseline profile of this standard will indicate that the patent owner is prepared to grant a free of charge license to an unrestricted number of applicants worldwide. Three codecs have responded to the CfP: Web video coding (WVC), video coding for browsers (VCB), and IVC. WVC is in fact the AVC baseline, and VCB uses the same coding tools as VP8. IVC has been developed in MPEG from scratch by combining well-known existing technology elements and new coding tools with royalty-free declarations. In June 2015, the IVC project was approved as ISO/IEC 14496–33 (MPEG-4 IVC). This standard can be highly beneficial for video services in the Internet domain. This paper describes the main coding tools used in IVC, and evaluates its objective and subjective performances compared with WVC, VCB, and AVC high profile (AVC HP). The experimental results show that IVC’s compression performance is approximately equal to that of the AVC HP for typical operational settings, both for streaming and low-delay applications, and is superior to WVC and VCB.