nils-herrmann/clean_scirepeval huggingface dataset:
GARCH based degradation modeling of solder joint under vibration loading

The degradation behavior of the solder joint under constant vibration loading is discussed, the voltage value at both sides of the solder joint is taken as the degradation characteristic. Considering the heteroskedasticity of characteristic signal under the vibration loading, the general time series model cannot describe heteroskedasticity, a Generalized Autoregressive Conditional Heteroskedastic model (GARCH) is proposed. Firstly, the upper and lower quantiles of the voltage signal are extracted. The failure time is determined by using the upper quantile and the degradation process is analyzed by the lower quantile. Secondly, the Auto-Regressive(AR) is built as the regressive basic model. Thirdly, a GARCH(1,1) model is proposed, which is tested by the Autoregressive Conditional Heteroskedastic (ARCH) method, the parameters of the model is estimated by the Maximum Likelihood algorithm. Finally, the performance of the presented GARCH based degradation model is examined by real data from experiment, which is compared with the classical AR model according to Akaike Information Criterion(AIC). The results suggest that GARCH(1,1) is superior to AR model, presented a theoretical foundation for further study about the degradation modeling of solder joint under vibration loading.
Review of board-level solder joint reliability under environmental stress

The reliability of board-level solder joint that provides the mechanical and electrical connections between the chip and print circuit board is such an import issue that they can result in the failure of the whole equipment under real service condition. The multiple stresses in service environment such as temperature and vibration loadings can cause the fatigue failure of solder joints easily. In this paper, a review was presented on the research situation and prospect of the reliability of solder joints with an emphasis on accelerated tests, numerical simulation and life prediction models. The failure behaviors of solder joints under coupling loadings of temperature and vibration were also introduced which represent the research trend in the future.
Short-term load forecasting for city holidays based on genetic support vector machines

Support vector machines (SVM), which are based on statistical learning theory and structural risk minimization principle, according to limited sample information, search the best compromise between the model complexity and the learning ability, and have good prediction effect. However, in the methods of load forecasting which are based on SVM, the choices of penalty coefficient c, insensitive coefficient ε and kernel parameter σ2 have a great impact on predictions, and may lead to large error results. This paper, using the powerful global optimization function, the implicit parallelism and other advantages of genetic algorithm (GA), searches the optimal values of SVM parameters c, ε and σ2 automatically, and improves its prediction performance. Then the genetic support vector machines (GA-SVM) is applied to holidays load forecasting of a city grid in Hebei province. The results indicate that the predicted effect of genetic support vector machines is better than that of the similar day forecasting method.
Strained Ge0.91Sn0.09 Quantum Well p-MOSFETs

Pseudomorphic Ge<sub>0.91</sub>Sn<sub>0.09</sub> on Ge on Si with strong photoluminescence and low defect density is used for p-MOSFET channels. The mobility of Ge<sub>0.91</sub>Sn<sub>0.09</sub> Quantum Well p-MOSFETs are higher than control Ge p-MOSFETs due to hole population in the GeSn wells. The 7.5% mobility enhancement on <;110> channel direction is observed using external transverse uniaxial tensile strain (~0.11%). The highest [Sn] of 9% in the channels grown by CVD, Pt SB S/D, high I<sub>on</sub>/I<sub>off</sub> ratio, and strain-enhanced mobility are obtained in this work.
Study on novel technologies for electrical energy saving in distribution network and its engineering applications

The electric energy saving system (EESS) for enterprise and city is proposed in this paper, which consists of three parts: electric energy saving equipments of high voltage, electric energy saving equipments of low voltage, and real-time reactive power optimal compensation. Three novel electric energy saving technologies are presented: high-quality hybrid var and harmonic compensator (HVHC) for high-voltage distribution network; low-cost and high-efficiency hybrid var compensator (HVC) for low-voltage distribution network; real-timely global optimization system of EESS. The characters of the three novel energy saving technologies are analyzed, respectively. Industrial practical effects confirm that the proposed EESS effectively solves the problems of electric energy saving in distribution network and ensures its operation securely and stably, as well as decreases the loss of electric energy greatly.
Additional fuel system optimization for CNG vehicle base on MDO method

Usually CNG vehicle is modified based on conventional vehicle in structure, the additional fuel system is very heavy due to its gas and structure, which increases the danger of potential gas leakage and explosion. Therefore the safety and reliability of the CNG vehicle should be highly emphasized. In this paper, we analyze the characteristic fuel structure of CNG vehicle and emphatically study on rear impact and NVH performance. A finite element model of CNG vehicle for rear impact and NVH analysis was created. Using OPTIMUS software with multidisciplinary feasible algorithm which integrated with Pam-Crash and MD Nastran software for collaborative optimization, we made the additional fuel system lighter and fit all requirements. From sensitivity analysis of initial design space we found sensitive ingredient of structure, and built response surface model for these sensitive parts as design parameters base on RBF function. We apply an adaptive evolutionary algorithm with discrete variables to find global optimal solution on response surface. Calculated results show that the response surfaces have high accuracy, and the optimization calculation converges very fast. Finally the mass of additional fuel system is significantly reduced, and the model and MDO method is proved to be effective and correct.
Neural Network and Nonlinear Prime-Dual Interior Algorithm for Optimization Reactive Power Compensation

This paper briefly analyses the conventional reactive power optimization compensation. The new method proposes a new optimization reactive power compensation for electrical network that uses neural network to predict electric network's important parameters and nonlinear prime-dual interior algorithm to optimize reactive power. This intelligent control system diminishes power losses, and settles the problems that the electric power has complicated parameters and it is hard to constitute the compensation system model. The result shows that the effect of this intelligent control system is good and this algorithm is valid.
A study on competitive location of express operation station

This thesis studies stackelberg competitive location problem of express operation station. Stackelberg competitive location planning model and market demand distribution model are established. Planning model based on attraction thought way that the leader making-decision of location of operation station is affected by decision- making of the follower, and considering market demand, delivery cost and management cost, in order to maximize the converted net profit of leader and follower. An example is given to illustrate.
Synthesis distortion estimation in 3D video using frequency and spatial analysis

We propose an analytical model to estimate the synthesized view quality in 3D video. Specifically, we estimate the depth-error induced distortion using an approach that combines frequency and spatial domain analysis. We also propose to decompose the spatial-variant video signals into gradient-based representations to capture the interaction between image gradients, depth errors and synthesis distortion. Experiment results with video sequences and coding/rendering tools used in MPEG 3DV activities show that our analytical model can accurately estimate the synthesis noise power.
Study on Chain Structure Model of Industry Clusters Grey Evolutionary Game Based on Symmetric Case

This paper designs a chain structure model of symmetric grey evolutionary game and describes replication dynamics of industry clusters whose payoff is symmetric and uncertain. On the basis of these, taking one symmetric grey evolutionary game of industry clusters as an example, we imitate and analyze its replication dynamics and evolutionary trace. Results show that there just exists unique equilibrium region of evolutionarily stable strategies(ess) in symmetric grey evolutionary game of industry clusters.
A Parallel Belief Propagation Decoding Algorithm for Rate Compatible Modulation

This letter proposes a parallel belief propagation algorithm for fast iterative decoding of rate compatible modulation. In this proposed algorithm, the processing at symbol node is partitioned into several low complexity sub-processors. All sub-processors have similar structures and work in parallel without cross connections among them. Numerical and simulation results show that proper partition results in significant reduction of the computational complexity without decoding performance degradation.
Measuring efficiency of hand surgery departments using data envelopment analysis(DEA)

This paper developed an approach based on data envelopment analysis(DEA) including CCR, BCC and FG models to evaluate the performance of hand surgery departments. Concerning the characteristics of hand surgery, the design of decision making unit(DMU) with 3 input indexes and 3 output indexes were conducted through the communication tool of IDEF0. Five sets of muti-index criteria were introduced to provide a comprehensive measurement. The approach was applied to a case study of 22 hand surgery departments in Mainland China. In the cases, the relative input-output efficiency of service quality, labor, medicine, and facility were measured, and several constructive suggestions about resources allocation and scale were proposed. The case study shows that this efficiency measurement method is applicable and instructive for hand surgery management.
Beyond SIFT using binary features in Loop Closure Detection

In this paper a binary feature based Loop Closure Detection (LCD) method is proposed, which for the first time achieves higher precision-recall (PR) performance compared with state-of-the-art SIFT feature based approaches. The proposed system originates from our previous work Multi-Index hashing for Loop closure Detection (MILD), which employs Multi-Index Hashing (MIH)  for Approximate Nearest Neighbor (ANN) search of binary features. As the accuracy of MILD is limited by repeating textures and inaccurate image similarity measurement, burstiness handling is introduced to solve this problem and achieves considerable accuracy improvement. Additionally, a comprehensive theoretical analysis on MIH used in MILD is conducted to further explore the potentials of hashing methods for ANN search of binary features from probabilistic perspective. This analysis provides more freedom on best parameter choosing in MIH for different application scenarios. Experiments on popular public datasets show that the proposed approach achieved the highest accuracy compared with state-of-the-art while running at 30Hz for databases containing thousands of images.
Flame Feature Model Development and Its Application to Flame Detection

In this study, both linear discriminant technique and logistic regression method are considered and compared to develop a flame feature model. Based on the comparison, the logistic regression method is chosen and plugged into a flame detection system for segmenting the fire regions. Some spurious fire-like regions are then removed by the image difference method and the invented color masking technique. Finally, a simple method is devised to estimate the burning degree of the fire flame so that users could be informed with a proper warning alarm. The proposed method is tested with twelve diverse fire flame video clips at the process speed of thirty frames per second. The proposed method can achieve more than 97% detection rate on the average. In addition, the system can correctly recognize fire flames within one second on the initial combustion from the test video clips, which seems very promising
Negative-sequence current compensation of power quality compensator for high-speed electric railway

In order to solve the power quality problem of high-speed electrified railway at 350km/h, this paper presents a new type of power quality compensation system, which is mainly made of railway regulator RPC, two sets of thyristor-controlled reactor and two sets of thyristor-controlled 3rd filter. The RPC is only used to transfer active power. The thyristor-controlled 3rd filters are used to suppress 3rd harmonic current and change the phase angle of power supply current. The thyristor-controlled reactors are as the same used to change the phase angle of power supply current. The proposed power quality compensator has small capacity and low cost. The working principle of negative sequence current compensation of the proposed power quality compensator is analysis. The simulation results have verified the correctness of the theoretical analysis in this paper, and the proposed power quality compensation system can reduce the capacity of the active part and have a good performance at negative sequence compensation.
Influence of interphase interference on resistive leakage current of MOA

The latent faults of the metal oxide surge arrester (MOA) can be found by on-line resistive leakage current monitoring. However, because of the influence of location and distributing mode of the MOA, the voltage of two other phases affect a single MOA by interphase interference, and this influences the monitoring accuracy of the MOA's resistive leakage current. A software analysis method for every phase influential factor is advanced. And we analyze the double CT method to eliminate this influence. Based on the double CT method, a bus-module on-line leakage current monitoring system for the MOA is developed.
Analysis method of compound uncertainty for water quality risk under cascade development mode

Aimed at the quantitative analysis for the run risk of water quality, an analysis method of grey-stochastic compound uncertainty for water quality risk under cascade development mode was established. Regarding respectively the many uncertainties affected the water quality risk and the compound uncertainty relationship among the various factors as random effect and grey relationship, thus establishing the risk analysis method of water quality based on grey-stochastic compound uncertainty, which derived based on an improved first-order second-moment method for solving method, the risk probability obtained by the grey-stochastic risk evaluation fell in a grey space, which satisfactorily reflected the uncertainty of water quality risk under cascade development mode. Project instance analysis shows that the complex uncertainty analysis method proposed can satisfactorily evaluate the potential risk of the water quality under cascade development mode.
Motion activity based wireless video quality perceptual metric

Due to its limited bandwidth, lossy compressed video is very important in wireless video transmissions. We propose a quality evaluation framework based on motion activity information, and two concepts, video definition and video smoothness are introduced into digital video metrics. The motion activity description method is essential to both aspects. Two simple but effective methods describing motion activities are presented first. Then, the role of motion activity played in the quality evaluation of video definition and video smoothness is set forth. The framework is fit for applications of a wide range.
Research on the method of multi-level linkage in virtual forest simulation information

Most forest simulation systems developed for a specific research objectives only use a growth model or simulation technology to simulate the single-granularity forest. It is very time consuming to recalculate growth model for the transformation between different granularity forest scenes. In order to realize the rapid transformation between different granularity forest scenes, this paper presents a method of multilevel linkage in virtual forest simulation information. This method builds the associations of different granularity forest scenes. It can realize continuous transformation from large granularity forest scenes to small granularity forest scenes, and vice versa. The experiment result shows that this method can effectively reduce the transformation time between different granularity forest scenes, and accelerate the rendering speed of large-scale forest scene.
Guided signal reconstruction with application to image magnification

We study the problem of reconstructing a signal from its projection on a subspace. The proposed signal reconstruction algorithms utilize a guiding subspace that represents desired properties of reconstructed signals. We show that optimal reconstructed signals belong to a convex bounded set, called the "reconstruction" set. We also develop iterative algorithms, based on conjugate gradient methods, to approximate optimal reconstructions with low memory and computational costs. The effectiveness of the proposed approach is demonstrated for image magnification, where the reconstructed image quality is shown to exceed that of consistent and generalized reconstruction schemes.
The step-power method study for the maximum power tracking of single-stage photovoltaic grid-connected inverter

Based on the characteristics of PV array model, static and dynamic mathematical models of the single-stage PV power grid-connected generation system under the condition of power control are established in this paper. The voltage trajectory of PV array is studied by means of phase diagram analysis, which provides the basis for designing the maximum power point tracking algorithm. A step-power tracking algorithm is proposed according to the trajectory analysis of PV array voltage. Without the DC side current sensor, the algorithm overcomes the shortcomings such as the collapse of the bus voltage caused by traditional perturbation and observation method, the incorrect tracking of maximum power point in the weak light case. The validity and correctness of this method is verified by simulations and experiments.
Keypoint trajectory coding on compact descriptor for video analysis

In contrast to still image analysis, motion information offers a powerful means to analyze video. In particular, motion trajectories determined from keypoints have become very popular in recent years for a variety of video analysis tasks, including search, retrieval and classification. Additionally, cloud-based analysis of media content has been gaining momentum, so efficient communication of salient video information to perform the necessary analysis of video at the cloud server is needed. This paper describes a novel framework to efficiently represent the keypoint trajectories. In particular, an interframe prediction is designed with the option to operate in a low-delay mode. Additionally, a scalable coding method is proposed that allows for a subset of the coded trajectories in a video segment to be easily accessed. Experimental results on several popular datasets including Stanford MAR and Hopkin155 demonstrate a significant rate saving of up to 25% with our proposed trajectory coding approaches relative to a state-of-the-art reference approach.
Approach to cooperative assembly task planning for multiple manipulators

It is very difficult to allocate the assembly tasks to multiple manipulators, because the number of manipulators is variable and each manipulator has different ability. This work presents an approach for cooperative assembly task planning for a multiple manipulators environment to improve the flexibility and reliability of the automated assembly system. In this paper, the hierarchical assembly precedence graph (HAPG) extended from the assembly precedence graph (APG) is proposed to describe the assembly sequences and the assembly process data necessary for the task allocations. The outline of the agent-based and cooperative assembly task planning system is presented, and this system starts from the HAPG and the information of the manipulator agents. For the sake of minimizing the makespan, the algorithm of task planning takes into account not only the assembly processing time but also the time needed for the manipulators to change tools. Some applications of this algorithm for a multiple manipulators environment are described.
Coding of faded scene transitions

Coding of a scene transition is often a challenging problem, from the compression efficiency point of view, because motion compensation may not be a powerful enough method to represent changes between pictures in the transition. This paper proposes a overlay coding technique for coding faded scene transitions. As shown by extensive simulations, over 50% bit-rate savings in both cross-fades and through-black fades compared to earlier techniques can be achieved. Overlay coding suits situations where video is edited manually or automatically.
Dispersion Characteristics of Thin-Film Waveguides with Two Dimensionally Sinusoidal Surface Corrugation

Rigorous apde-rpakhing techniques are used to salve the boundary value problem with tw-dimensionally C2D) sinusoidal corrugation in addition to the ordinary flat interface. Dispersion characteristics of the whole structure are presented. New physical effects of 2D periodic structure can be seen and rrnderstoad fran nurperical results. IHIEoWcnON 20 periodical surf- corrugatim in a planar guiding structwe can cause many new attractive physical effects based an which my circuits and devices for aiaawave, milliaeter and infrared waves can be established. Theexperinental phenosreM of the light propagaticm in 2D periodic planar waveguide have bean studied and summized (11. Several plethodr have been used in analysis. (hedidonally corrugated gratings has been rigorously analyzed using coupled-Wve analysis t23. By dividing the surface corrugation inb a large number of thin Cplanu) layers then treating one layer at a ti=, the results are thewetically obtainable bo an arbitrary level of accuracy. ht tha practidly treatable number of layers and lcIhe Roject supported by NatioMf WenCe Foundation
Optical formula recognition based on structural features

Automatic recognition of formulas is one of the key parts in an OCR system. It could be really useful to be able to re-use knowledge in the scientific books which are not available in electronic form. A method of optical formula recognition is described. It consists of two major steps, namely, symbol recognition and structural analysis. Firstly, the search and process connect the components to gain the symbol components followed by symbol recognition. After that, we analyze the structure of the formula on the basis of the recognition result and the geometry features. The system works reliably on almost noiseless images obtained by scanning among the usual documents clearly printed.