nils-herrmann/clean_scirepeval huggingface dataset:
Nonlinear Message Expansion for Hash Function

This paper carries out a statistical analysis on the nonlinear diffusion & propagation of the SHA message expansion. The nonlinear expansion of the message is realized through the rolled-out and folded-over of the integer tent maps, and a piece-wise-nonlinear message expansion scheme is further given. Compared with SHA-256 message expansion, the message expansion mode presented in this paper has enhanced the degree of nonlinear diffusion of the message expansion, and thus improved computation efficiency.
Notice of RetractionDetermination of Thiourea by High Performance Liquid Chromatography with Different Solvents

Thiourea is a toxicant which will brings some adverse affects to the public health, even in some cases is fatal. The detection of thiourea by High Performance Liquid Chromatography (HPLC) on different solvents, as methanol, ethanol and ultrapure water were studied respectively. The results showed that the concentrations between 0.5 μ g/mL and 5.0 μ g/mL, the peak area of thiourea in three different solvents had a good relationship with its solution concentrations, the correlation factor were all above 0.98, under the same chromatogram condition as 40% methanol and 60%ultrapure water as the mobile phase, flow rate of the mobile phase was 0.6mL/min, UV-VIS detector at 242nm, column oven was at 30°C, sample size was in 10μL, When used the ultrapure water as the solvent, the relative standard deviation (RSD) ranged from 1.19% to 2.21%, the recovery rate was 88.9%, which demonstrated the method was correct and reliable, and accuracy rating was high.
Nonrandom quantization errors in timebases

Timebase distortion causes nonlinear distortion of waveforms measured by sampling instruments. When such instruments are used to measure the rms amplitude of the sampled waveforms, such distortions result in errors in the measured rms values. This paper looks at the nature of the errors that result from nonrandom quantization errors in an instrument's timebase circuit. Simulations and measurements on a sampling voltmeter show that the errors in measured rms amplitude have a non-normal probability distribution, such that the probability of large errors is much greater than would be expected from the usual quantization noise model. A novel timebase compensation method is proposed which makes the measured rms errors normally distributed and reduces their standard deviation by a factor of 25. This compensation method was applied to a sampling voltmeter and the improved accuracy was realized.
Short Circuits of a 10-MW High-Temperature Superconducting Wind Turbine Generator

Direct Drive high-temperature superconducting (HTS) wind turbine generators have been proposed to tackle challenges for ever increasing wind turbine ratings. Due to smaller reactances in HTS generators, higher fault currents and larger transient torques could occur if sudden short circuits take place at generator terminals. In this paper, a finite element model that couples magnetic fields and the generator's equivalent circuits is developed to simulate short-circuit faults. Afterward, the model is used to study the transient performance of a 10-MW HTS wind turbine generator under four different short circuits, i.e., three-phase, phase–phase clear of earth, phase-phase-earth, and phase-earth. The stator current, fault torque, and field current under each short circuit scenario are examined. Also included are the forces experienced by the HTS field winding under short circuits. The results show that the short circuits pose great challenges to the generator, and careful consideration should be given to protect the generator. The findings presented in this paper would be beneficial to the design, operation and protection of an HTS wind turbine generator.
Gain estimates and exponential ISS for a class of hybrid dynamical networks

This paper studies the exponential input-to-state stability (e-ISS) for hybrid dynamical networks (HDNs) consisting of flow and jumping subsystems. Concepts of input-to-state exponent (IS-E) and event-ISS are proposed. By using the IS-E estimates of subsystems and the method of multiple Lyapunov functions and M-matrix theory, the e-ISS including event-e-ISS criteria are established for HDNs. The small-gain condition for the coupling of flows is needed while such condition for the coupling of impulses is not necessary. It also shows that a HDN may have ISS even all subsystems have no ISS. Finally, one example is given to illustrate the results.
Image annotation via social diffusion analysis with common interests

Automatic annotation of images is of crucial importance in image retrieval and management systems. Most of the existing annotation methods rely on content-based approach to annotation, whose effectiveness is restricted due to the semantic gap between low-level features and semantic annotations, as well as the irrelevance between annotations and image content. Recently, social media analysis has been investigated for image annotation. Inspired by the abundant social diffusion records of images in online social networks, we propose a novel image annotation approach based on social diffusion analysis. We present a common-interest model to interpret social diffusion, i.e. different images have different social diffusion routes due to the preferences of users, and such preferences are represented as common interests of pairwise users rather than personalized interests. We propose an image annotation framework that consists of learning of common interests, feature extraction from social diffusion records, and automatic annotation by learning to rank. Experimental results on a real-world dataset show that our proposed approach outperforms content-based and user-preference-based annotation methods.
A convolutional neural network-based approach to rate control in HEVC intra coding

Rate control is an essential element for the practical use of video coding standards. A rate control scheme typically builds a model that characterizes the relationship between rate (R) and a coding parameter, e.g. quantization parameter or Lagrange multiplier (A). In such a scheme, the rate control performance depends highly on the modeling accuracy. For inter frames, the model parameters can be precisely updated to fit the video content, based on the information of previously coded frames. However, for intra frames, especially the first frame of a video sequence, there is no prior information to rely on. Therefore, intra frame rate control has remained a challenge. In this paper, we adopt the R-A model to characterize each coding tree unit (CTU) in an intra frame, and we propose a convolutional neural network (CNN) based approach to effectively predict the model parameters for every CTU. Then we develop a new CTU level bit allocation and bitrate control algorithm based on the R-A model for HEVC intra coding. The experimental results show that our proposed CNN-based approach outperforms the currently used rate control algorithm in HEVC reference software, leading to on average 0.46 percent decrease of rate control error and 0.7 percent BD-rate reduction.
A novel one-bit feedback collaborative beamforming algorithm using two time slots

Collaborative beamforming is an effective approach when transmitting common message to a relatively distant destination. In collaborative beamforming, it is necessary to compensate the unknown phase offset for the phase alignment at the receiver. We introduce a new method for the one-bit feedback collaborative beamforming scheme to achieve the phase alignment. The receiver feeds back one bit at each time slot, but the transmitters exploit two successive feedback bits, including the current and last feedback bits, to make decision. The algorithm can adjust the step of random perturbation and the size of directional factor accordingly. The results show that less time slots are required to achieve the phase alignment and the convergence speed is improved greatly.
Fractal dimension estimation of groundwater depth series of well irrigation area in Sanjiang Plain based on continuous wavelet transform

In order to reveal the groundwater depth series complexity characteristic of well irrigation area in Sanjiang Plain, taking Jiansanjiang branch bureau as example, the fractal dimension estimation method of hydrological series based on continuous wavelet transform was adopted to analyze the complexity of groundwater depth series in 7 production teams of Jiansanjiang branch bureau. The results show that the wavelet fractal dimension estimation method is robust and feasible. The complexity order of each groundwater depth series from big to small is as follows:69th production team of Farm Qixing, 22th production team of Farm Qianjin, 4th production team of Farm Qianjin, 1th production team of Farm 859, 11th production team of Farm Qianjin, 26th production team of Farm 859, 21th production team of Farm 859. We can see that the groundwater exploitation is the key driving factor of groundwater depth complexity. The research achievements reveal the characteristic of local groundwater resources complex system and provide decision basis for scientifically managing groundwater resources in Jiansanjiang branch bureau so much as the entire Sanjiang Plain.
Simulation research on distributed energy consumption in active distribution network

The micro-grid technology has its limitation in the management of large- scale and extensive distributed energy resource (DER). While active distribution network (ADN) can not only manage the DER actively, but also interact with the demand side, so that large-scale DER can be consumed. By using simulation method and evaluating efficiency of DER and the consumption capability of different consumption patterns, this paper analysis the simulation result of the consumption process in ADN.
Research on a flexible waveform power amplifier adopting Switch-Linear Hybrid(SLH) Scheme

A novel power amplifier adopting switch-linear hybrid scheme (SLH-FWPA) is introduced to accomplish flexible waveforms power amplification in a high bandwidth at high output power rating. The final output stage of SLH-FWPA is derived from linear power amplifier architecture to maintain excellent output quality and well dynamic performance; and meanwhile using tracking power supplies for the linear output stage to acquire total system efficiency above 80% generally. Theoretic analysis for SLH-FWPA is given and experimental results verify the implementation of SLH-FWPA.
Application of Analytic Hierarchy Process in Optimization Selection of Groundwater Artificial Recharge Methods in Sanjiang Plain

With the rapid increase of paddy area, the groundwater level of well irrigation paddy area in Sanjiang Plain has widely declined in recent years, which has led to more and more “hanging pump”, partial overpumping and a series of water environmental problems. Therefore, the groundwater resource dynamic balance in Sanjiang Plain needs to be recovered urgently. In order to solve above-mentioned problems, taking Hongxinglong branch bureau of Heilongjiang state farm for example, this paper optimizationally selects and sorts groundwater artificial recharge methods with the analytic hierarchy process (AHP for short), and proposes large-diameter well recharge is the optimum method. The study can provide scientific gist for groundwater artificial recharge practice and sustainable development of agriculture in Hongxinglong branch bureau and even the entire Sanjiang Plain. Analytic Hierarchy Process ; Sanjiang Plain ; groundwater artificial recharge methods ; large-diameter well recharge
Effects of Armature Winding Segmentation With Multiple Converters on the Short Circuit Torque of 10-MW Superconducting Wind Turbine Generators

Superconducting synchronous generators (SCSGs) are drawing more attention in large direct-drive wind turbine applications. Despite low weight and compactness, the short circuit torque of an SCSG may be too high for wind turbine constructions due to a large magnetic air gap of an SCSG. This paper aims at assessing the effects of armature winding segmentation on reducing the short circuit torque of 10-MW SCSGs. A concept of armature winding segmentation with multiple power electronic converters is presented. Four SCSG designs using different topologies are examined. Results show that armature winding segmentation effectively reduce the short circuit torque in all the four SCSG designs when one segment is shorted at the terminal.
Hierarchical quadtree-based flexible block ordering in HEVC intra coding

In all of the existing block-based image and video coding standards, blocks are processed in the fixed scan order. Then in HEVC intra coding, intra prediction is always based on the top and/or left neighboring reconstructed pixels, which incurs less accurate prediction for blocks where the spatial correlation is not along the topleft-to-bottomright direction. To obtain better intra prediction, we propose to flexibly determine the coding order of blocks in HEVC intra coding. Complying with the hierarchical quadtree structure in HEVC, our flexible block ordering (FBO) technique recursively decides the coding order of four sub-blocks when splitting one block. Moreover, we propose new methods to perform inter/extrapolation for intra prediction so as to fully utilize neighboring reconstructed pixels, not always being top/left. Experimental results show that our proposed FBO technique achieves on average 2.9% BD-rate reduction compared to HEVC baseline.
Research on the mechanism of contractor support for new-type equipment

One of the current trends in most armies of the world is to reduce the size of the military, but this may cause serious problems in manpower for equipment support. To resolve this problem, the best way is to make use of non-military resources in the form of contractor support. This paper discusses the necessity and feasibility of using contractor support for new-type equipment based on the requirements for adapting the Chinese military to high-tech war, the requirements for achieving transformation in military affairs and the requirements for civil-military integration in equipment support.
Effects of Cyber Coupling on Cascading Failures in Power Systems

In this paper, we propose a model to investigate the cascading failures in the coupled system (smart grid) that comprises a power grid and a coupling cyber network. In this model, we take into consideration the effects of power overloading, contagion, and interdependence between power grids and cyber networks on failure propagations in the coupled system, and then use a stochastic method to generate the time intervals between failures, thus producing the dynamic profile of the cascading failures caused by the attack of cyber malwares. We study several coupled systems generated by coupling the UIUC 150 Bus System with cyber networks of different structures and coupling patterns. Simulation results show that the dynamic profile of the cascading failures in a coupled system displays a “staircaselike” pattern which can be interpreted as a combined feature of the typical step propagation profile triggered repeatedly by cyber attacks due to network coupling. Results also show that cyber coupling can intensify both the extent and rapidity of power blackouts. Moreover, the cyber network structure and the coupling patterns affect the propagation of the cascading failures in smart grids. Scale-free cyber networks promote failure spreading, and the higher average cyber node degree also intensifies the spreading. Coupling power nodes with high-degree cyber nodes accelerates the failure propagation compared with random or low-degree couplings.
Lithology Identification Methods Contrast Based on Support Vector Machines at Different Well Logging Parameters Set

Based on the coring well and well logging data, according to three methods, including M-N value, curve superposition and curve characteristic value, which are often be used on lithology identification, three different well logging curve parameters set was collected, joining with SVM, lithology identification was fulfilled, after that, to selecting the best well logging parameters set that suitable to used on lithology identification according to error minimum principle through contrasting the results. Results show that two of three different parameters set indicated the error minimum characteristic on the process, those are curve superposition value and curve characteristic value, the parameters sets of curve superposition value and curve characteristic value methods can be the preferable fundamental data to be used on lithology identification from well logging.
A Power Flow Algorithm with Three-Order Convergence Rate

A power flow algorithm with three-order convergence is proposed, which make full use of the second order derivative information of power flow equations, and it can decrease the iterations effectively. To reduce calculation burden of Hession matrix, A new power flow model is given in the paper. Both node voltages and injected currents are treated as variables. Traditional power flow equations are departed to linear network equations and nonlinear node equations. The Hession matrix of the nonlinear equations is const matrix with simple structure. Simulation results of IEEE test cases and several real systems show that the proposed method can converge after only 2~3 iterations with fast speed.
Inversion-Optimization Method for Determination of Longitudinal Dispersion Coefficient in River

To overcome the difficulty in the identification of parameter of the water environmental system caused by the limited observation data with noise, a new method, namely inversion-optimization method, was suggested for determination of longitudinal dispersion coefficient in river. The method which based on one dimensional water quality model with instantaneous source, was validated by a test. The influences on parameter estimation of observation norse, instrument precision were discussed in detail. The computational results indicate that inversion-optimization method can give good precision inversion results for tracer test.
A New Type Real-Time Simulation Platform for Modular Multilevel Converter Based HVDC

This paper focused on a new type simulation platform. Restricted by the number of network nodes and time step, traditional all digital simulation platform is not fast enough for the modular multilevel converter Based HVDC (MMC-HVDC). This paper presented a real-time digital-analog hybrid simulation platform including 49-level MMC, described the method of calculating the proportion of the platform to the original system. The characteristics of the simulation platform were designed according to the dynamic response features of actual system and its converter was simulated by analog devices. Depending on the special communication interface the simulation platform can also be used to verify the function of converter valve based controller (VBC) used in the Nanhui MMC-HVDC project. Experiment results of severe bipolar short circuit fault are compared with that by off-line digital simulation platform PSCAD, showing that most of the dynamic characteristics are basically identical. Thus the simulation system is verified available for optimization of dynamic parameters and real-time test of control system in planning of MMC-HVDC system.
Analysis of fatigue damage repair based on laser shock processing for copper film

The effect of laser shock processing on fatigue life was investigated for pre-damaged polycrystalline copper film in this study. First, a series of laser shock processing experiments is performed by changing laser power density and number of pulses for the specimens with the same damage degree. The optimal repairing parameters of laser shock processing is identified by comparing with the fatigue lives of specimens before and after laser shock processing. Next, the effect of laser shock processing on the fatigue lives of the damaged and undamaged specimens under identical laser shock processing parameters is investigated. Finally, the opportunity of repair damage for the specimens with different damage degrees is discussed using the optimal processing parameters for the laser shock processing. The results indicated that laser shock processing has a great potential as a means of repairing the fatigue damage for film components.
A detection method for response time of overall primary frequency regulation of power grid

In this paper, a deep information mining is carried out for the frequency variation data curve during grid power shortage based on the grid frequency control mechanism. Considering the difference characteristics of system frequency response process with or without a governor provided for the grid, it is proposed to use the grid failure frequency data with a high sampling rate measured and recorded by phasor measurement unit (PMU) to calculate the maximum system frequency deviation and determine the actual action response time of overall primary frequency regulation (PFR) of grid by detecting the variation of the maximum frequency deviation. Both the simulation examples and the calculation results of actual grid data indicate that this method can provide relatively accurate references for evaluating the response time of overall primary frequency regulation of the grid.
Distributed PrefixSpan algorithm based on MapReduce

For mining sequential patterns on massive data set, the distributed sequential pattern mining algorithm based on MapReduce programming model and PrefixSpan is proposed. Mining tasks are decomposed to many small tasks, the Map function is used to mine each Prefix-Projected sequential pattern, and the projected databases were constructed parallelly. It simplifies the search space and acquires a higher mining efficiency. Then the intermediate values are passed to a Reduce function which merges together all these values to produce a possibly smaller set of values. Both theoretical analyses and experimental results show MR-PrefixSpan reduces the time of scanning database. It solves the problem of mining massive data effectively, has considerable speedup and scaleup performances with an increasing number of processors on the Hadoop platform.
Improved decoding algorithm and structure of turbo space-time coded modulation

Bandwidth efficient turbo codes have demonstrated good performance in single-antenna links. This paper is motivated by the need for applying such approaches to multiple-antenna links, and fulfilling relatively low-complexity decoding method in a turbo space-time coded modulation system. Our scheme evolved from symbol-interleaved turbo trellis coded modulation, then to make an iterative decoding procedure fit in multiple-antenna links, the zero-forcing algorithm and an antenna selector are introduced in a 2-transmitter system.
An Improved Algorithm of LEACH Routing Protocol in Wireless Sensor Networks

In order to solve the problems of LEACH (Low Energy Adaptive Clustering Hierarchy) nodes short life cycle and consumption imbalance, the paper proposes an improved algorithm of LEACH. The main idea of the improved algorithm is to consider the current position and the current energy of the node, which can be more evenly distributed cluster head, in order to prolong the life cycle of the node. A comparison is made between LEACH protocol and NEW-LEACH protocol. Simulation result shows that the improved protocol increases by 40.7% in survival time.