nils-herrmann/clean_scirepeval huggingface dataset:
Low power readout circuit for 384×288 uncooled IRFPA with novel readout stage

A readout integrated circuit for 384×288 uncooled infrared focal plane array (IRFPA) is presented in this paper. To overcome the kickback to sample and hold stage with less power consumption, a novel readout stage of a Class AB op-amp with input stage in each column and sharing one cascode output stage is introduced. This IRFPA readout circuit has been designed and fabricated in 0.35um CMOS technology. The readout speed of the circuit can reach 7MHz, the dynamic range is 86.5dB and power consumption is 108mW. A 32×32 experimental chip has been verified by test results.
A coordinated primary frequency regulation from Permanent Magnet Synchronous Wind Turbine Generation

As a growing number of Permanent Magnet Synchronous Wind Turbine Generations (PMSG-WT) are integrated into the modern power grid, there has been a great concern for system operators who expects PMSG-WT to play an active role in the primary frequency regulation when frequency event occurs. However, PMSG-WTs are still unable to provide any additional active power in response to the system frequency change. In this work, a control scheme of coordinated frequency regulation for DFIG is redesigned and implemented into a PMSG-WT model by synthesizing the inertial control, over-rotor speed control and pitch angle control. Inertial control emulates the total inertia response of both wind turbine and generator to provide a short-term frequency support. According to the de-loaded optimum power extraction curve, the over-rotor speed and pitch angle controls are coordinated to maintain the reserved power and meanwhile assist the primary frequency regulation in a long-term period. The coordinated control strategy of PMSG-WT comprises the low, medium and high wind speed modes. By this means, the comprehensive control method will promote the PMSG-based wind farms to effectively participate in the system frequency regulation under a full scope of wind speed conditions.
Elimination of numerical oscillations in power system dynamic simulation

This paper addresses numerical oscillations encountered in power system dynamic simulation resulting from trapezoidal numerical integration rule. Two methods are presented to eliminate the numerical oscillations: trapezoidal with numerical stabilizer method and Gear's second order method. A detailed comparison is given regarding the accuracy of the trapezoidal rule, trapezoidal with numerical stabilizer method, and Gear's method. The validity of the new methods is demonstrated in the simulation of a power electronic circuit within Virtual Test Bed. The new methods are of great significance in performing a meaningful simulation for power electronics circuits.
An error robust distortion model for depth map coding in error prone network

Error robustness becomes an important issue when the compressed depth map is transmitted over error prone network. There have been some algorithms to improve the error robustness of color video in the past years. However, their extension to depth map are not reasonable due to the difference between depth map and color video. In this paper, a novel error robust distortion model is proposed to enhance the error robustness of depth map, in which the end-to-end distortion of virtual view is estimated. More specifically, the proposed distortion model recursively computes the expected decoded depth for each pixel by considering the channel condition and error concealment method, and then the expected decoded depth is used to estimate the end-to-end distortion of virtual view. Experimental results show that the proposed distortion model consistently outperforms the conventional distortion model and outperforms the random intra updating algorithm in most cases.
A multiple vectors voltage waveform modulation method for microgrid inverter

Voltage waveform distortion scenario exists and this phenomenon greatly diminishes the efficiency of electric power conversion when the conventional SVPWM method is applied in microgrid inverter. In order to solve the problems, a Multiple Vectors Pulse Width Modulation (MVPWM) method based on 12 voltage vectors is proposed. The modulation method we proposed defines 12 voltage vectors in the space vector plane and the reference voltage vector is created by synthesizing two adjacent voltage vectors and the zero voltage vectors. The proposed method does not lose some advantages which belong to conventional SVPWM method such as simplified calculation character and easy implementation feature. Furthermore, MVPWM can effectively avoid the upper and lower switch states of a leg short-circuiting the voltage source so that there is no additional requirement to set the dead-time. Therefore, the effect of dead-time to the inverter and the distortion of voltage waveform can be decreased. From another perspective, the efficiency of electric power conversion can be increased. The validity of the proposed MVPWM method has been verified by both theoretical analysis and simulation results.
Image matching based on a local invariant descriptor

Image matching is a fundamental task of many computer vision problems. In this paper we present a novel approach to match two images in presenting significant geometric deformations and considerable photometric variations. The approach is based on local invariant features. First, local invariant regions are detected by a three-step process which determines the positions, scales and orientations of the regions. Then each region is represented by a novel descriptor. The descriptor is a two-dimensional histogram. Performance evaluations show that this new descriptor generally provides higher distinctiveness and robustness to image deformations. We present the image matching results. The matching results show good performance of our approach for both geometric deformations and photometric variations.
Multimedia security in the distributed environment

Multicast is very useful way for large-scale distributing multimedia over the network. It can significantly reduce the bandwidth required to transmit same multimedia over the network to multiple receivers. This property makes multicast competitive and attractive. We propose a simple and efficient scheme in order to resolve the issue mentioned above. In our scheme, the content provider generates two different watermarked packets for even' data packet firstly. Next, he encrypts every two watermarked packets by two different keys, respectively. Finally, he multicasts all of encrypted packets with encrypted keys to intended receivers. In the receiver, only one of every pair of encrypted packets is decrypted relying on the ID stored in tamper-resistant hardware. Every receiver obtains unique watermarked packets because every ID is unique. So, the watermarked packets can be used to trace those receivers who make redistribution of received multimedia content illegally.
Distributed Video Coding Based on the Human Visual System

This letter proposes a distributed video coding (DVC) scheme based on the human visual system (HVS). As we know, HVS can seldom sense any changes below the just-noticeable-difference (JND) distortion threshold due to its underlying sensitivity and masking property. Therefore, the un-noticeable signal differences between the original frame and side information need not to be corrected in DVC. Experimental results demonstrate that the proposed algorithm can save the bits-rates significantly without degrading the subjective quality of the reconstructed frames.
Multi-level low-complexity coefficient discarding scheme for video encoder

Rate-Distortion (R-D) optimization technique plays an important role in video coding. R-D sense discarding (thresholding) technique can make great improvement on the coding efficiency. This work first proposes a multi-level coefficient discarding scheme, which is composed of coefficient-level (CL), block-level and macroblock-level discarding. In CL, coefficient-level R-D cost function is formulated and then CL discarding scheme is developed. At last, an effective implementation method is proposed to reduce the complexity of the proposed scheme. The experimental results show that our proposed multi-level discarding scheme can improve the coding performance of video encoder by 0.15db in average.
Correlation preserving on graphs for image denoising

In this paper, we propose a novel dictionary-driven image denoising method based on correlation preserving on graphs. To overcome the drawbacks of the instable and unreliable correlations among a set of learned basis vectors, two effective regularized strategies are employed in our coding process. Specifically, a graph-based regularizer is built to preserve the global similarity, which can adaptively capture both geometric structures and discriminative features of textured patches. In particular, edge weights in the graph are obtained by seeking a nonnegative low-rank construction. Besides, a locality constraint is designed to automatically preserve not only spatial neighborhood information but also internal consistency present in noisy patches while learning an overcomplete dictionary. Experimental results show that our method achieves state-of-the-art denoising results in terms of both PSNR and subjective visual quality.
A low-complexity hardware-oriented mode decision scheme based on rate-distoration estimation

Video compression plays an important role in mobile applications, because more and more people use video to communicate with each other (like video call etc). However, the resources (energy, memory etc.) on mobile devices are limited, thus how to achieve a high coding performance in these devices becomes a big challenge. The recent standards such as H.264, HEVC and audio video coding standard (AVS) employ Rate distortion optimization (RDO) to select the best coding modes, however it results in extremely high computational complexity. This work presents a hardware friendly mode decision (MD) scheme. First, hardware-oriented RDcost estimation method is proposed by using least squares technique to reduce computational burden of RDO-based MD. Second, reconstructed-original (REC-ORG) united intra prediction scheme is presented to break the data dependency, while maintaining high coding performance. Third, highly efficient MD pipeline architecture is put forward to enhance MD processing capacity. The coding efficiency of our adopted MD scheme far outperforms (0.402 dB PSNR gain in average) the traditional SAD methods and the throughput of our designed pipeline is increased by 29%, 23% and 23% for I, P and B frames, respectively, compared with the existed RDO-based architecture.
Action Recognition in Broadcast Tennis Video

Motion analysis in broadcast sports video is a challenging problem especially for player action recognition due to the low resolution of players in the frames. This paper presents a novel approach to recognize the basic player actions in broadcast tennis video where the player is about 30 pixels tall. Two research challenges, motion representation and action recognition, are addressed. A new motion descriptor, which is a group of histograms based on optical flow, is proposed for motion representation. The optical flow here is treated as spatial pattern of noisy measurement instead of precise pixel displacement. To recognize the action performed by the player, support vector machine is employed to train the classifier where the concatenation of histograms is formed as the input features. The experimental results demonstrate that our method is promising
Chip waveform design for DS/SSMA systems with aperiodic random spreading sequences

In direct-sequence spread-spectrum multiple-access (DS/SSMA) systems with matched filter receivers, the chip waveform affects not only the system bandwidth efficiency, but also the error performance. This is because the statistical property of the multiple-access interference (MAI) depends on the actual shape of the chip waveform as well as its energy. In this paper, we propose an approach to design waveforms that may result in interchip interference (ICI) and derive a criterion for design based on the conditional Gaussian approximation (CGA) of the MAI for systems with aperiodic random spreading sequences. A novel performance metric including the effect of ICI is derived. Based on this metric, a closed form solution for optimal band-limited waveforms is obtained for excess bandwidth less than or equal to one. Numerical results, based on an analytical method as well as Monte-Carlo simulations, are provided to evaluate the performance of the proposed waveforms in systems with conventional matched filter receivers.
A 14-bit 8-column shared SAR ADC for 640×512 IRFPA

This paper presents a new structure of column-level successive approximation register (SAR) analogue-to-digital converter (ADC) for Infrared Focal Plane Array. In this design, each column has a capacitance array and each comparator and SAR logic block are shared by 8 columns. By using this shared structure, we achieved smaller silicon area, lower power dissipation and lower noise. And shared structure leaves enough space for signal and control wires of ADC blocks, therefore relieves the mutual disturbance among wires. Also, correlated switches are used to cancel the offset generated by charge injection. The conversion accuracy of the proposed ADC is 14 bits and is used for a 640×512 array with a frame rate of 50Hz.
A 16-bit two-step pixel-level ADC for 384∗288 infrared focal plane array

This paper presents a novel 16-bit pixel-level analog-to-digital converter (ADC) for the 384∗288 Infrared Focal Plane Array (IRFPA). It is a two-step ADC: the first is coarse quantization, and the second is fine quantization. Coarse quantization is to process the most significant 12 bits using a voltage reset method. Fine quantization is to dispose the remaining 4 bits by applying a falling multistep signal on the bottom plate of the integrating capacitor. The ADC is implemented in standard SMIC 0.18μm 1.8V/5V CMOS process, with 100Hz sampling rate.
A low power ROIC design for 1024×1024 IRFPA

A low power Read-Out Integrated Circuit (ROIC) for a short-wave Infra-Red Focal Plane Array (IRFPA) is designed as a prototype for 1024×1024 image system. Ripple integration and readout scheme as well as highly efficient power management is introduced to this design in order to decrease total power dissipation. To overcome the charge sharing problem caused by this low power readout scheme, novel low input capacitance column amplifier is proposed. The Data rate is about 10 M/s per channel, with a total power dissipation of 56 mW.
Matching graph connectivity of LDPC codes to high-order modulation by bit interleaving

The decoding threshold and the error floor are two key performance metrics that are commonly used to evaluate the goodness of a LDPC code design. For a finite-length irregular LDPC code employing sub-optimal iterative decoding algorithm, the major factors that determine the decoding threshold and the error floor are nodes degree distribution as well as the edge permutation associated with its tanner graph. In addition, due to the non-uniform bitwise error protection inherent to a high-order constellation (e.g. 256-QAM, 1024-QAM), generally there exists a mismatch between the encoder and the modulator unless a dedicated ldquoouterrdquo bit interleaver (de-multiplexer) is plugged between the two modules to match the non-uniform bits reliability. Motivated by the requirement for high spectral efficiency in the development of future DVB-C standard as well as the industrial trend for reusing the LDPC codes standardized in DVB-S2 specification, in this paper we focus on the design of the ldquoouterrdquo bit interleaver, assuming the LDPC code and the order 22Q constellation mapper are fixed a priori. The configuration for the proposed bit interleaver is solved by optimizing the degree profiles of Q ldquosubcodesrdquo, subject to the constraints of the degree distribution given by the ldquomotherrdquo code. Besides, to prevent the error-prone patterns existing in the ldquomotherrdquo code to cause decoding failures, an extra constraint is imposed on the allocation of low-degree coded bits to the constellation mapper. Compared with the random interleaving approach, the proposed bit interleaver can achieve significant gains in both the waterfall and the error floor regions.
Simulation study of permanent magnet synchronous machine direct drive wind power generator using three level NPC converter system

In this paper, two three-phase three-level Neutral Point Clamped (NPC) converters connected back-to-back are used for a direct drive wind power generator. A permanent magnet synchronous generator (PMSG) is used as the generator, which is driven by the wind turbine. Main problem of voltage unbalance in each electrolyte capacitor is controlled by using a simple chopper control circuit. A simple hardware method for balancing the Neutral Point (NP) voltage is proposed, which allows enhanced ride-through performance. This method can effectively balance the NP voltage without the limitations of modulation methods and load conditions. It also provides increased ride-through capabilities for the inverter during input voltage sags. Because of the NP balancing, the necessary size of the dc-bus capacitors is reduced. Here, MATLAB/SIMULINK simulation results are presented for the validity of proposed scheme.
Enhanced intra coding with joint line and pixel prediction

Existing video coding standards always employ line-based intra prediction for intra frame coding. However, it sometimes does not perform well for the bottom-right boundary pixels due to the low correlation with the referenced pixels. In this paper, we propose a novel joint line and pixel prediction (JLPP) method to compensate the performance degradation of boundary pixels. In JLPP, each block is partitioned into two subblocks, including a P-subblock covering bottom and right pixels and a L-subblock comprising the rest pixels. L-subblock will firstly be predicted and coded in a similar way to H.264/AVC intra coding. Secondly, a gradient-adjusted prediction scheme is applied to P-subblock with the aid of the reconstructed pixels in L-subblock. Therefore, the reconstruction qualities of the boundary pixels used to predict the subsequent blocks can be enhanced. Experimental results demonstrate that the proposed method achieves a PSNR gain of up to 0.63dB compared with H.264/AVC intra coding.
Simulation and Research of Fuzzy Immune Adaptive PID Control in Coke Oven Temperature Control System

Aiming at the coke oven's temperature characteristics of great inertia, pure time-delay, non-linear and time changeable, a fuzzy adaptive PID control method is presented based on the immune feedback regulating law and the adaptive ability of fuzzy logic ratiocination. The academic analysis and simulation results of coke oven's simple model indicate the feasibility and effectiveness the control method
Improved chicken swarm optimization

Considering the problem that the original chicken swarm optimization algorithm is easy to fall into local optimum because of premature convergence for high-dimensional complex problems, an improved chicken swarm optimization was proposed. In this algorithm, the part of chicks learning from the rooster in their subgroup is added to chick's position update equation, and the inertia weight and learning factor are also introduced. Then eight benchmark functions are used to test the proposed algorithm and the comparison with particle swarm optimization, bat algorithm, and original chicken swarm optimization are also performed. The simulated experimental results showed that the proposed algorithm is able to avoid premature convergence and therefore can escape from local optimum. Especially, the proposed method outperforms other evolutionary algorithms in finding the global optimum for high-dimensional problems.
An efficient and robust adaptive deinterlacing technique

This paper presents an efficient and robust adaptive deinterlacing technique that consists of three main steps, i.e. motion estimation, motion detection (MD), and adaptive decision-making. Firstly, five successive interlaced fields are used and four unidirectional motion vectors are calculated. Secondly, a probabilistic criterion is introduced to select the most reliable motion vector for each block before MD, which has four possible output motion states. Finally, an adaptive deinterlacing scheme is proposed based on the motion and texture information of each block, as well as the output of MD. Experimental results show that the proposed deinterlacing technique outperforms previous methods both objectively and subjectively. The analysis also shows that the proposed technique is robust to both unconventional motions and the video codec
Blind adaptive estimation and diversity combining of a fast varying, correlated multipath channel for DS/SS systems

The maximum ratio combining (MRC) of a fast varying, correlated multipath fading channel is investigated. A practical solution to the problem of simultaneously estimating the channel state and the channel parameters is proposed. Based on the expectation maximization (EM) algorithm, the procedure of iterating batches of data is simplified to an adaptive algorithm with only forward time recursions, which helps remove the required training sequences, and significantly reduces the memory requirement. Through computer simulations, we have found a near ideal MRC BER performance and demonstrated the efficacy of the new algorithm when applied to channels with changing Doppler spreads.
Image compressive-sensing recovery using structured laplacian sparsity in DCT domain and multi-hypothesis prediction

In compressive sensing (CS), the seeking of a fair domain is of essentially significance to achieve a high enough degree of signal sparsity. Most methods in the literature, however, use a fixed transform domain or prior information that cannot exhibit enough sparsity for various images. Superiorly, we propose an algorithm to explore the structured Laplacian sparsity of DCT coefficients, which can adapt to the non-stationarity of natural images. Better sparsity is achieved by utilizing the nonlocal similarity of natural images and constructing structured image patch groups. Meanwhile, multiple hypotheses for each pixel could be obtained owing to the overlapping of the structured groups and similar patches. Additionally, for solving the optimization problem formulated from the techniques above, we design an efficient iterative method based on split Bregman iteration (SBI) algorithm. Experimental results demonstrate that the proposed algorithm outperforms the other state-of-the-art methods in both objective and subjective recovery quality.
Fault diagnosis for down-hole conditions in beam pumping units based on an improved fuzzy Iterative Self-Organizing Data Analysis Technique

Dynamometer cards are commonly used to analyze down-hole conditions of beam pumping units in practical oil production. In the literature, supervised learning based methods heavily rely on training samples. In order to realize unsupervised learning of fault diagnosis for down-hole conditions, a method based on an improved fuzzy Iterative Self-Organizing Data Analysis Technique (ISODATA) with “merging” and “splitting” mechanisms is proposed in this paper. The Hsim similarity function is used to replace the Euclidean distance to improve the classification accuracy in high-dimensional space. In “merging” and “splitting” mechanisms, the “minimum distance between two classes” is a very important parameter to affect clustering accuracy and is difficult to be accurately set in advance. It is considered as a variable parameter and is dynamically adjusted in the clustering process. Simulated annealing algorithm is used to realize optimization and Xie-Beni (XB) validity index is used as the optimization target. An example is given to illustrate that the proposed method can realize dynamic clustering with a better effectiveness.