nils-herrmann/clean_scirepeval huggingface dataset:
Study on promoting integration of large scale wind employed the 750kV controllable shunt reactor

By the end of 2010, the 750kV double circuit power transmission project from Dunhuang to Wusheng in Gansu had been put into operation, aimed at promoting the integration of large scale wind power, and solving the technology and practical problems caused by the intensively exploitation and long-distance transmission of the wind power. But the transportability of the power transmission line was impacted seriously by the frequent and large-amplitude fluctuations of the reactive power and voltage, and the bus voltage is more difficult to control. The 750kV controllable shunt reactor (CSR) which has been operated in Dunhuang substation of Gansu in 2011 provides a very efficient technological means of solving these problems. The super grid of Hexi of Gansu paralleled with the CSR is modelled in this paper. The action situation of the CSR and the influence to the system reactive power and voltage are studied, when the capacity of integrated wind power changes. The integrated capacity was measured at Dunhuang substation, the actual result of the CSR to promote the integration of the large scale wind power is revealed qualitatively and quantitatively.
A parallel computing method for fault diagnosis based on Hadoop

To improve the efficiency and the speed of fault diagnosis for multimode process under big data environment, a new parallel computation fault diagnosis approach, called GFCM-VMD-HM, is proposed for multimodal TE process based on Hadoop platform. Firstly, the global fuzzy c-means (GFCM) clustering algorithm is applied to distinguish the operation modes. Then, Variational Mode Decomposition(VMD) algorithm is introduced for the sake of filtering. After that, the data are encoded string files and put to Hadoop Distributed File System (HDFS). Finally, character statistics program is written to output multiple files under MapReduce data frame to complete the fault feature extraction and diagnosis. An experimental study is carried out to evaluate the performance of the proposed algorithm. The results obtained show that the method saves fault diagnosis time by means of parallel computing.
Video denoising using a spatiotemporal statistical model of wavelet coefficients

We propose a video denoising algorithm based on a spatiotemporal Gaussian scale mixture (ST-GSM) model in the wavelet transform domain. This model simultaneously captures local correlations between the wavelet coefficients of natural video sequences across both space and time. Bayes least square estimation is used to recover the original signal from the noisy observation. To further improve the performance, motion compensation is employed before ST-GSM denoising, where a Fourier domain noise-robust cross correlation approach is proposed for motion estimation. Experiments show that the performance of the proposed method is highly competitive when compared with state-of-the-art video denoising algorithms.
Objective Quality Assessment for Image Retargeting Based on Structural Similarity

We propose an objective quality assessment method for image retargeting. The key step in our approach is to generate a structural similarity (SSIM) map that indicates at each spatial location in the source image how the structural information is preserved in the retargeted image. A spatial pooling method employing both bottom-up and top-down visual saliency estimations is then applied to provide an overall evaluation of the retargeted image. To evaluate the performance of the proposed IR-SSIM algorithm, we created an image database that contains images produced by different retargeting algorithms and carried out subjective tests to assess the quality of the retargeted images. Our experimental results show that IR-SSIM is better correlated with subjective evaluations than existing methods in the literature. To further demonstrate the advantages and potential applications of IR-SSIM, we embed it into a multi-operator image retargeting process, which generates visually appealing retargeting results.
Polarity Information Coded Flip-OFDM for Intensity Modulated Systems

A polarity-information-coded flip orthogonal frequency division multiplexing is proposed for intensity modulation/direct detection optical communications in this letter. In the proposed scheme, the modulated signals in the frequency domain are not constrained to have Hermitian symmetry. The real and imaginary parts of the time-domain complex signals are separated, and the polarities of the real and imaginary parts are jointly encoded and modulated. The transmit strategy and the receive algorithm of the proposed scheme are analyzed in detail. The major advantage of the proposed scheme is that its spectral and optical power efficiencies are higher than existing schemes, which is validated in simulation.
SSIM-inspired divisive normalization for perceptual video coding

We propose a perceptual video coding framework based on an SSIM-inspired divisive normalization scheme as an attempt to transform the DCT domain frame prediction residuals to a perceptually uniform space before coding. Based on the residual divisive normalization process, we define a distortion model for mode selection and show that such a divisive normalization strategy largely simplifies the subsequent perceptual rate-distortion optimization procedure. Experiments demonstrate that the proposed scheme can achieve significant gain in terms of rate-SSIM performance in comparison with H.264/AVC.
Performance Analysis of Multi-Antenna Hybrid Satellite-Terrestrial Relay Networks in the Presence of Interference

The integration of cooperative transmission into satellite networks is regarded as an effective strategy to increase the energy efficiency as well as the coverage of satellite communications. This paper investigates the performance of an amplify-and-forward (AF) hybrid satellite-terrestrial relay network (HSTRN), where the links of the two hops undergo Shadowed-Rician and Rayleigh fading distributions, respectively. By assuming that a single antenna relay is used to assist the signal transmission between the multi-antenna satellite and multi-antenna mobile terminal, and multiple interferers corrupt both the relay and destination, we first obtain the equivalent end-to-end signal-to-interference-plus-noise ratio (SINR) of the system. Then, an approximate yet very accurate closed-form expression for the ergodic capacity of the HSTRN is derived. The analytical lower bound expressions are also obtained to efficiently evaluate the outage probability (OP) and average symbol error rate (ASER) of the system. Furthermore, the asymptotic OP and ASER expressions are developed at high signal-to-noise ratio (SNR) to reveal the achievable diversity order and array gain of the considered HSTRN. Finally, simulation results are provided to validate of the analytical results, and show the impact of various parameters on the system performance.
Embedded foveation image coding

The human visual system (HVS) is highly space-variant in sampling, coding, processing, and understanding. The spatial resolution of the HVS is highest around the point of fixation (foveation point) and decreases rapidly with increasing eccentricity. By taking advantage of this fact, it is possible to remove considerable high-frequency information redundancy from the peripheral regions and still reconstruct a perceptually good quality image. Great success has been obtained previously by a class of embedded wavelet image coding algorithms, such as the embedded zerotree wavelet (EZW) and the set partitioning in hierarchical trees (SPIHT) algorithms. Embedded wavelet coding not only provides very good compression performance, but also has the property that the bitstream can be truncated at any point and still be decoded to recreate a reasonably good quality image. In this paper, we propose an embedded foveation image coding (EFIC) algorithm, which orders the encoded bitstream to optimize foveated visual quality at arbitrary bit-rates. A foveation-based image quality metric, namely, foveated wavelet image quality index (FWQI), plays an important role in the EFIC system. We also developed a modified SPIHT algorithm to improve the coding efficiency. Experiments show that EFIC integrates foveation filtering with foveated image coding and demonstrates very good coding performance and scalability in terms of foveated image quality measurement.
Pricing-Based Distributed Energy-Efficient Beamforming for MISO Interference Channels

In this paper, we consider the problem of maximizing the weighted sum energy efficiency (WS-EE) for multi-input single-output (MISO) interference channels (ICs), which are well acknowledged as general models of heterogeneous networks (HetNets), multicell networks, etc. To address this problem, we develop an efficient distributed beamforming algorithm based on a pricing mechanism. Specifically, we carefully introduce a price metric for distributed beamforming design, which fortunately allows efficient closed-form solutions to the per-user beam-vector optimization problem. The convergence of the distributed pricing-based beamforming design is theoretically proven. Furthermore, we present an implementation strategy of the proposed distributed algorithm with limited information exchange. Numerical results show that our algorithm converges much faster than existing algorithms, while yielding comparable, sometimes even better performance in terms of the WS-EE. Finally, by taking the backhaul power consumption into account, it is interesting to show that the proposed algorithm with limited information exchange achieves better WS-EE than the full information exchange-based algorithm in some special cases.
Research on noise source identification of traction motor system for electric buses based on sound intensity

The characteristics of the Electric Vehicle (EV) traction motor system are different from the traditional industrial motor system, and the noise source are also different with different conditions. Based on the theory of sound intensity, the experiments of noise source identification of the Electric Vehicle traction motor system are research through the measurement at discrete points firstly. The noise source of the whole motor are analyzed in details, and the main noise frequencies is 3600 Hz and 5800 Hz. The figure of noise source identification with different frequencies received and 1/3 octave to sound intensity and sound pressure as well as the noise spectrum characteristics can be acquired. In addition, according to the experiments, the noise spectrum characteristics of each part of the Electric Vehicle motor system have been established.
On the multiple-access capacity of multitone-CDMA communications

This paper derives a bit-error-probability expression for an asynchronous multitone-code-division multiple access (CDMA) system and shows that the multiple-access (MA) capacity of this system is identical to that of a conventional (single-carrier) direct-sequence spread-spectrum system under conditions of equal bandwidth and equal bit rate. It is also shown that using more subcarriers to increase the processing gain does not increase the MA capacity.
Automatic Segmentation of Fuzzy Laser Lines with Sub-Pixel Accuracy from the Uneven Background During Robotic Arc Welding

Robust and automatic segmentation of the reflected laser lines from the arc light modified background is prerequisite for the subsequent measurement of the weld pool shape which is of great importance for monitoring robotic arc welding. In this paper, the two dimensional intensity distribution caused by the arc light in the captured image is modeled. Based on the model, we propose an efficient and effective method that comprises three parts: (1), spline enhancement to achieve sub-pixel accuracy, (2), a gradient detection filter to eliminate the uneven background, (3), an effective threshold selection method. Experimental results verified that the proposed method is significantly superior to other state of art methods in segmentation accuracy.
Subjective quality assessment of Screen Content Images

Research on Screen Content Images (SCIs) becomes important as they are increasingly used in multi-device communication applications. In this paper, we present a study of subjective quality assessment for distorted SCIs, and investigate which part (text or picture) contributes more to the overall visual quality. We construct a large-scale Screen Image Quality Assessment Database (SIQAD) consisting of 20 source and 980 distorted SCIs. The 11-category Absolute Category Rating (ACR) is employed to obtain three subjective quality scores corresponding to the entire image, textual and pictorial regions respectively. Based on the subjective data, we investigate the applicability of 12 state-of-the-art Image Quality Assessment (IQA) methods for objectively assessing the quality of SCIs. The results indicate that existing IQA methods are limited in predicting human quality judgement of SCIs. Moreover, we propose a prediction model to account for the correlation between the subjective scores of textual and pictorial regions and the entire image. The current results make an initial move towards objective quality assessment of SCIs.
The impact of dynamic range on open-loop power control error

Direct sequence code division multiple access (DS-CDMA) techniques have received a great deal of attention for current and future communication systems. One of the major considerations in implementing a DS-CDMA system is the necessity for accurate power control to ensure adequate quality-of-service and capacity. This paper investigates the measurement error of an open-loop power control algorithm under transmit power limitation. The power control error is analysed and numerically computed.
Bitplane-by-bitplane shift (BbBShift) - A suggestion for JPEG2000 region of interest image coding

The JPEG2000 image coding standard defines two kinds of region of interest (ROI) coding methods-the general scaling based method and the maximum shift (maxshift) method. The former requires shape coding of the ROIs, which leads to increased complexity of codec implementations and limits the choice of ROI shapes (currently, only rectangle and ellipse shapes are defined). The latter allows for arbitrarily shaped ROI coding without explicitly transmitting any shape information to the decoder, but does not have the flexibility to select an arbitrary scaling value to define the relative importance of the ROI and the background wavelet coefficients. We propose a bitplane-by-bitplane shift (BbBShift) method, which supports both arbitrary ROI shape and arbitrary scaling without shape coding.
Perceptual evaluation of multi-exposure image fusion algorithms

Multi-exposure image fusion is considered an effective and efficient quality enhancement technique widely adopted in consumer electronics products. Nevertheless, little work has been dedicated to the quality assessment of fused images created from natural images captured at multiple exposure levels. In this work, we first build a database that contains source input images with multiple exposure levels (≥ 3) together with fused images generated by both classical and state-of-the-art image fusion algorithms. We then carry out a subjective user study using a multi-stimulus scoring approach to evaluate and compare the quality of the fused images. Considerable agreement between human subjects has been observed. Our results also show that existing objective image quality models developed for image fusion applications either poorly or only moderately correlate with subjective opinions.
Performance of one-hop/symbol FHMA for cellular mobile communications

This paper is concerned with the bit-error rate (BER) performance of a cellular one-hop/symbol frequency-hopping multiple-access (FHMA) system operating through a multipath Rayleigh fading channel. M-ary frequency shift keying modulation with noncoherent square-law envelope demodulation and Reed-Solomon (RS) coding is considered. The multiple-access and adjacent cell interference of the cellular FHMA system has been studied. In order to illustrate how sensitive both systems are to the near/far problem, performance of the FHMA system is compared with that of a direct-sequence code-division multiple-access system for an equal system bandwidth. Also, this paper investigates the effect of the values of frequency reuse factor (N) on the system capacity of the cellular frequency-hopping system.
Electroluminescent Image Processing and Cell Degradation Type Classification via Computer Vision and Statistical Learning Methodologies

A data set of 90 60-cell module images from 5 commercial PV module brands over 6 exposure steps of damp-heat testing were analyzed. An automated data analysis pipeline was developed using the open source coding language Python to parse the module images into individual cell images. As the original raw images are not directly suitable for modeling, this algorithm implements techniques which include filtering, thresholding, convex Hull, regression fitting, and perspective transformation to pre-process the original image. After cell extraction, 5400 individual cell images as a function of brand and exposure time were obtained. From the data set, 3 initial degradation categories were observed: good, cracked, and heavily busbar-corroded. For supervised machine learning classification, these images were manually sorted into these 3 categories yielding 3550 images. To increase the data set size, the cell images were augmented by flipping the images about the x-axis and y-axis as well as rotated 180 degrees. This increased the total sample size to 14,200 images with good, cracked, and heavily corroded counts of 12,004, 492, and 1704, respectively. A training and testing framework was generated using stratified sampling with a training to testing data ratio of 80:20. The statistical learning algorithms Support Vector Machine (SVM), Random Forest (RF), and Artificial Neural Network (ANN), were independently trained on the training set and then given the remaining data images to predict their classification. The results showed model prediction accuracies of 98.77%, 96.60%, and 98.13% for the SVM, RF, and ANN models, respectively.
An image pixels based fast matching algorithm for Die Bonder targeting

Auto Die Bonder (ADB) is often encountered in the IC package field, whose key technical difficulty lies in quickly and accurately locating the bonding positions of the chips. In this paper, a normalized cross correlation (NCC) algorithm based on image pixels has been used to address this problem. By using iterated algorithm with simplified expression, the modified NCC (MNCC) is remarkably accelerated compared to the traditional one. Afterwards, the MCNN algorithm has been examined by experiments to locate the lead-frame pads, and the result shows its superiority in efficiency with satisfactory positioning accuracy.
High dynamic range image tone mapping by optimizing tone mapped image quality index

An active research topic in recent years is to design tone mapping operators (TMOs) that convert high dynamic range (H-DR) to low dynamic range (LDR) images, so that HDR images can be visualized on standard displays. Nevertheless, most existing work has been done in the absence of a well-established and subject-validated image quality assessment (IQA) model, without which fair comparisons and further improvement are difficult. Recently, a tone mapped image quality index (TMQI) was proposed, which has shown to have good correlation with subjective evaluations of tone mapped images. Here we propose a substantially different approach to design TMO, where instead of using any pre-defined systematic computational structure (such as image transformation or contrast/edge enhancement) for tone mapping, we navigate in the space of all images, searching for the image that optimizes TMQI. The navigation involves an iterative process that alternately improves the structural fidelity and statistical naturalness of the resulting image, which are the two fundamental building blocks in TMQI. Experiments demonstrate the superior performance of the proposed method.
A novel scheme for underwater acoustic mobile communications

The underwater acoustic channel is a complicated and time-varying multipath channel, especially for the mobile applications in the littoral. To accommodate the execrable channel conditions, a robust communication scheme is proposed, which combines the differential frequency hopping(DFH) and multi-carrier technologies. Also a novel Doppler-shift estimation and synchronization method is presented, which utilizes the doppler-invariant hyperbolic frequency modulation(HFM) signal associating with the doppler-sensitive long single tone pulse. Simulation results demonstrate that the proposed communication scheme performs well for underwater acoustic mobile communications with relative velocity up to 30 knots at data rate about 300bps. Base on these preliminary results, the proposed scheme shows considerable promise for reliable underwater acoustic mobile communications.
On the use of a suppression filter for CDMA overlay

This paper is concerned with a direct-sequence code-division multiple-access (DS-CDMA) system operating over a Rayleigh fading channel and sharing a common spectrum with a narrow-band waveform. A suppression filter at the receiver is employed to reduce the narrow-band interference. We evaluate the average up-link bit error rate (BER) performance and investigate how the performance is influenced by various parameters, such as the number of taps of the suppression filter, the number of multiple-access users, the ratio of narrow-band interference bandwidth to the spread-spectrum bandwidth, the interference power to signal power ratio, the ratio of the offset of the interference carrier frequency from the spread-spectrum carrier frequency to the half spread-spectrum signal bandwidth, and so on.
Video quality assessment using structural distortion measurement

Objective image/video quality measures play important roles in various image/video processing applications, such as compression, communication, printing, analysis, registration, restoration and enhancement. Most proposed quality assessment approaches in the literature are error sensitivity-based methods. We follow a new philosophy in designing image/video quality metrics, which uses structural distortion as an estimation of perceived visual distortion. We develop a new approach for video quality assessment. Experiments on the video quality experts group (VQEG) test data set shows that the new quality measure has higher correlation with subjective quality measurement than the proposed methods in VQEG's Phase I tests for full-reference video quality assessment.
A Patch-Structure Representation Method for Quality Assessment of Contrast Changed Images

Contrast is a fundamental attribute of images that plays an important role in human visual perception of image quality. With numerous approaches proposed to enhance image contrast, much less work has been dedicated to automatic quality assessment of contrast changed images. Existing approaches rely on global statistics to estimate contrast quality. Here we propose a novel local patch-based objective quality assessment method using an adaptive representation of local patch structure, which allows us to decompose any image patch into its mean intensity, signal strength and signal structure components and then evaluate their perceptual distortions in different ways. A unique feature that differentiates the proposed method from previous contrast quality models is the capability to produce a local contrast quality map, which predicts local quality variations over space and may be employed to guide contrast enhancement algorithms. Validations based on four publicly available databases show that the proposed patch-based contrast quality index (PCQI) method provides accurate predictions on the human perception of contrast variations.