nils-herrmann/clean_scirepeval huggingface dataset:
An Pilot-Assisted Channel Estimation Method for OFDM Systems in Time-Varying Channels

Orthogonal frequency division multiplexing (OFDM) systems encounter performance degradations due to the time varying (TV) channels in wireless environments. As delay spread increases, symbol duration should also increase, and then OFDM systems become more susceptible to time-variations. Time-variations introduce inter-carrier interference (ICI), which must be mitigated to improve the performance in high delay and Doppler spread environments. In this paper, we propose a method to estimate the TV channel. The method is designed for the comb pilot pattern. It performs a multi- symbol processing of the LS estimate over the pilot sub- carriers to detect the active paths of the channel and uses a piece-wise linear model to approximate the time-variations characteristic of each active path during each OFDM symbol to mitigate ICI. Theoretical analysis and simulation result show performance improvement in high delay and Doppler spread environments.
Modelling and simulation of underwater target's typical motion

In order to make the target's motion model more reasonably so as to improve detection probability of subsequent search action, according to different situations about whether target takes countermeasure or not, the target's motion can divide into three kinds, no countermeasure, countermeasure and uncertain information. Secondly, the forecast method of target's future position distribution based on three motions is explained respectively. Then, the motion model is proved validity by using simulation at last. This method will be worthful for the search tactics study to a certain extent.
Multiclass Least Squares Wavelet Support Vector Machines

A novel admissible support vector (SV) kernel, namely modified L-P wavelet kernel, is proposed based on theoretic analysis. The wavelet kernel can approximate arbitrary curve in quadratic continuous integral space, thus the generalization ability of the support vector machines (SVM) is improved. Based on the wavelet kernel function and the multiclass least squares support vector machines (MLS-SVM), the multiclass least squares wavelet support vector machines (MLS-MLPWSVM) is presented. The spiral multiclass classification experimental results show some advantages of MLS-MLPWSVM over MLS-SVM on the classification and the generalization performance.
Privacy Preserving Data Mining Algorithms by Data Distortion

Recently, a new class of data mining methods, known as privacy preserving data mining (PPDM) algorithms, has been developed by the research community working on security and knowledge discovery. The aim of these algorithms is the extraction of relevant knowledge from large amount of data, while protecting sensitive information simultaneously. In this paper, we present a generic PPDM framework and a classification scheme for centralized database, adopted from early studies, to guide the review process. Frequencies of different techniques/algorithms used are tableau and analyzed. A set of metrics and a theoretical framework are also proposed for assessing the relative performance of selected PPDM algorithms. Finally, we share directions for future research
Particle Swarm Optimization Programming

PSO is a parallel stochastic optimization algorithm with advantages of less parameters and high efficiency. This paper describes the programming problem in the method of two linear tables with discrete and continuous quantity, then uses discrete PSO algorithm to discrete optimization and continuous PSO to optimize continuous quantity in the solving process respectively, based on these proposes the Particle Swarm Optimization Programming algorithm. Finally, GP and PSOP algorithms are compared by applying them to solving programming problem respectively with three typical test functions, the results show that the PSOP algorithm has better convergence precision and stability than the GP algorithm.
Stereoscopic Perceptual Video Coding Based on Just-Noticeable-Distortion Profile

Stereoscopic video coding is a key technology for the development of three-dimensional television (3DTV). Nonetheless, the task remains highly challenging owing to the large amount of 3DTV. Traditional stereoscopic video coding is found to be ineffective in reducing the unnecessary stereoscopic perceptual redundancy. Thus better compression efficiency is highly desired in stereoscopic video coding. In this paper, we propose a foveation weight model based on auto-stereoscopic display, and incorporate it into a stereoscopic just-noticeable-distortion (JND) model to give more accurate estimation of the stereoscopic perceptual effect. In order to utilize this model to improve the stereoscopic video coding efficiency, we present a block-adaptive residue preprocessing method based on stereoscopic JND model. Extensive experiment results demonstrate that the proposed scheme can efficiently reduce the unnecessary perceptual redundancy without visual quality degradation.
The Classification, Design and Placement of Security Sensor for Network Security Situational Awareness System

Network security situational awareness system (NSSAS) is one of the hotspots in information security domain. In order to solve the problem of NSSAS security situation information acquisition, it is highly necessary to study security sensors. On the basis of knowing the information requirement of NSSAS, we put forward a kind of classification method of security sensors, design a general architecture of security sensor, point out some key technologies related to implementing security sensors, give some placement policies, and discuss the management architecture and methods of security sensors finally.
A Universal Protection Controller for Li-ion Battery Charger

A universal protection controller for Li-ion battery charger is proposed in this paper. First, an in-depth analysis on Li-ion battery charger protection has been made, then a detailed system description was given, and finally test results were presented. This IC provides battery thermal protection, due time termination, bad cell detection, automatic recharge and state indication, which are usually neglected in conventional charger design. Furthermore, a new approach has been introduced to implement the battery thermal control unit for the system. With the battery thermal protection module, the charge current could be set according to a typical, not the worst-case, ambient temperature, which helps to accelerate the charging process. A novel oscillator without comparator is designed to generate the system clock. The protection controller IC was fabricated in 1.5 Â?m BCD (Bipolar CMOS DMOS) technology. The proposed functions of the IC were verified by simulation and measurement.
Development of sweetness sensor for high-potency sweeteners using lipid polymer membrane

High-potency sweeteners are applied to low-calorie diets and bitterness-masking ingredients in pharmaceutical products. We have studied taste sensors with lipid polymer membranes based on potentiometric measurement system for high-potency sweeteners. However, the sensor also responds to astringency substances because of hydrophobic characteristics of the lipid polymer membrane. In this study, we developed a new taste sensor using a lipid polymer membrane for saccharin sodium and acesulfame potassium as negatively charged high-potency sweeteners. We optimized the quantities and types of lipids and plasticizers for the fabrication of the sensor with high selectivity and sensitivity. We succeeded in the fabrication of the new sensor, the output of which could be suppressed under −5 mV for astringency substances. Moreover, the sensor has a good sensitivity and selectivity for saccharin sodium and acesulfame potassium.
Power quality detecting based on fast lifting wavelet transform

This paper advances a novel method for power quality detection by using fast lifting wavelet transform and utilizing the reconstructed signal to compensate for the harmonics. After the disturbed signal is decomposed to many sub-bands in frequency domain, the disturbing time and level can be identified and the disturbed signal can be compensated by the reconstructed signal. In this paper, the theory of fast lifting wavelet transform is given and the lifting wavelet of Daubechies(9/7) is applied to detect voltage sag, transient disturb and harmonics. Simulations validate that the method display a good detecting performance in both time and frequency domain and can depict the strange characteristics of the signal. Compared to traditional wavelet transform, the lifting wavelet transform depresses calculation complexity, effectively reducing calculation time and no additional memory is required, thus it is more practicability.
A study on packaging of PZT MEMS microphone

Packaging is the key issue in the commercialization of micromechanical microphone (also known as MEMS microphone). The ferroelectric-micromechanical microphone would have higher sensitivity and better acoustics performance. The microphone's package will play a role in protecting the MEMS microphone chip, providing signal channel, shielding the electromagnetism interference from circumference as well. Furthermore, the acoustic performance of microphone is affected by package construction. The design and fabrication of a surface mount package for the PZT microphone is presented in this paper. The microphone chip and amplifier are integrated on an organic substrate, on which a metal cap is attached for EMI shielding. The sensitivity at 1kHz is -36.8dB (14.5mV/Pa) for packaged microphone. The selection of adhesives has been optimized to ensure enough shear strength and satisfied performance. Three types of adhesives were used for die attachment. Optical profiler was used to measure the surface topography of the PZT film before and after attachment. A comparison of failure modes after shear test, for different adhesives was made for materials selection. The acoustic performance affected by different configuration of the package has been investigated. The inlet hole on the cap can restrain the response at high frequency. Packaged microphones were evaluated after thermal cycling and thermal storage.
Alteration of BBB tight junction protein expression induced by EMP exposure

In this study, we examined the effects of exposure to electromagnetic pulse(EMP) on the functional integrity of the BBB and, on the expression of tight junction (TJ) protein (occludin, ZO-1) in rats. Animals were whole body exposed or sham exposed to EMP at 200 kV/m for 400 pulses. The permeability of BBB was examined using Evans Blue (EB) as vascular tracer. The expression of the level of TJ proteins were assessed by western blot. The data indicated that EMP exposure caused increased permeability of BBB and decreased levels of TJ protein ZO-1. These results suggested that the alteration of ZO-1 may play an important role in the disruption of tight junctions, which may lead to dysfunction of the BBB after EMP exposure.
Auditory responses to short-wavelength infrared neural stimulation of the rat cochlear nucleus

Pulsed Infrared laser is well-known for its high spatial resolution and contact-free stimulation mode. In order to improve the current auditory brainstem implants (ABI), 980 nm-short-wavelength infrared light was applied to stimulate the cochlear nucleus of rats. Single neural activity from contralateral inferior colliculus was recorded during laser stimulation. Animal experimental results showed that 980 nm laser could not directly activate neurons in cochlear nucleus and a photo-acoustic response was observed during stimulation, however, 980 nm laser produces an inhibitory effect on neural responses to sounds; After we added carbon nanoparticles onto the surface of animal cochlear nucleus, 980 nm laser could directly stimulate neurons and no interference between adjacent recording channels was observed. These findings indicated that with the enhancement of carbon nanoparticles, short-wavelength infrared neural stimulation (SW-INS) might be an effective method to overcome the defects of current ABIs. With this method, a new type of optical ABI with transcutaneous stimulating method is quite promising.
An innovative design of light collimator based on freeform microlens array

This study presents an innovative freeform lens used in the NLIS (Natural Light Illumination System). The NLIS is used to guide the natural light indoors for illumination, which system is implemented in energy saving smart buildings to reduce energy consumption. The freeform lens is based on microlens array to collimate the light from the collecting sub-system before entering the light transmitting sub-system. Results show better parallelism can be achieved for later light transmission.
Face recognition based on circularly symmetrical Gabor transform

In this paper, we propose a face recognition approach using circularly symmetrical Gabor transform (CSGT). The traditional Gabor transform is replaced by CSGT. All the face images are transformed by CSGT first and then face recognition is performed in CSGT feature space. Detailed theoretical analysis is presented and simulation results on Yale, AR and ORL face databases are given. The recognition rates can reach 92.59%, 85.29% and 97.5% respectively by the proposed algorithm.
High performance adaptive robust control for nonlinear system with unknown input backlash

A high performance adaptive robust control (ARC) algorithm is developed for a class of nonlinear system with unknown input backlash, parametric uncertainties and uncertain nonlinearities disturbances. Due to the inherent dynamic nonlinear nature of backlash, existing robust adaptive control methods mainly focus on using on-line parameter adaptation for an approximate inversion of the unknown backlash. As a result, even in the absence of other uncertain nonlinearities and disturbance, asymptotic output tracking can never be achieved by continuous controller for the non-smooth characteristics of backlash. Experimental results also show that a linear controller alone performed better than a controller including the selected backlash inverter with a correctly estimated or overestimated backlash gap. Unlike many existing control schemes, the backlash inverse is not constructed in this paper. A new linearly parameterized model for backlash is presented and the projection algorithm is used for parameters estimation. The proposed adaptive robust control law consists of three parts: model compensation term, the robust control term and robust feedback term. The ARC ensure that all closed-loop signals are bounded and achieves the tracking within the desired precision. Simulations results illustrate the performance of the ARC.
RFID application challenges and risk analysis

RFID application becomes the focus recently. As an automatic identification technology, RFID has many advantages over traditional one like barcode. It does bring about tremendous changes, and also face lots of barriers during investment. In this paper, we integrate technology risk, IT risk and RFID risk, develop a RFID risk factor framework with analogy method, and find out the relationship between RFID uncertainty and RFID risk. Subjective Scoring Method is adopted to assess RFID risk level. Finally, RFID risk management methods for different kinds of risks are provided.
A Research on Automatic Modulation Recognition with the Combination of the Rough Sets and Neural Network

Automatic modulation recognition of modulation signals is the key problem in non-cooperative communication systems. The method which combines the rough set theory and the neural network is designed for identifying the six modulation types based on the research on the feature set of digital modulation recognition. Simulation results show that the new method simplifies the structure of neural networks and decreases the training time without reducing the recognition rate.
NbTi superconducting composite with high critical current density

In order to make NbTi50/Cu superconducting composite obtain high critical current density, we have studied carefully the melting method for NbTi50 alloy and the effect of cold work and heat treatment on critical current density. The results show that the ingots obtained through vacuum arc and a vacuum skull furnace melting can be used to fabricate NbTi superconducting composite with high critical current density. Cold work and heat treatment are the important factors which effect the critical current density of NbTi50/Cu superconducting composite. The restarts show that intermediate ageing treatments have improved the critical current density of NbTiSO/Cu composite. If a sample is treated intermediately for several times before final ageing, the Jc of the sample is much higher than that of the final aged sample of the same ageing time. As the intermediate ageing number is increased, the value of Jc (5T,4.2K) increased. It increased rapidly especially at the second and the third ageing. When the cold work between ageing treatments is increased, the value of Jc (5T, 4.2K) increased markedly. The heavier the cold work between ageing treatments is, the higher the Jc (5T, 4.2K) will be. Final deformation has further improved the critical current density of NbTi50/Cu composite in our range of experiment, Jc (5T, 4.2K) increased rapidly for the samples aged at 350°C and 385°C when the final deformation increased. The value of Jc (5T, 4.2K) comes up to 3.4 × 105A/cm2for the sample of the final deformation 90% after the last ageing at 385°C. In order to make NbTi50/Cu superconducting composite obtain high critical current density, cold work and heat treatment must be regulated and coordinated appropriately. We have chosen suitable heat treatment and cold work so that the highest critical current density has reached 3.9-4.14 × 105A/cm2(5T, 4.2K) for the optimum NbTi50/Cu multifilamentary composite.
Non-fragile H∞ filter design for two-dimensional foransini-marchesini systems

This paper addresses the problem of non-fragile H∞ filter design for two-dimensional systems. This filter has interval-type gain variation, which means that it cannot be fully performed. Firstly, by Finslers'lemma, the nonfragile filter design has been formulated as a robust convex optimization problem, which is solved by the classic vertex algorithm. It should be noticed that, for high dimensional systems, the number of LMIS involved is so large that it may be over the processing capacity of Matlab LMI Toolbox. To solve this difficulty, an efficient randomized algorithm is proposed. This algorithm can reduce the number of LMI conditions significantly. Finally, a numerical example is given to illustrate the effectiveness of the proposed method.
The Business Model Innovation of Mobile Operators: A Case Study on ADC/MAS Model of China Mobile

The coming of 3G era, bringing wider bandwidth and higher transmission rate, has also given many challenges to mobile operators. Mobile operators’ monopoly role in the value chain has been weakened. In order to create new value and consolidate of monopoly role, mobile operators have to change the existing business model. This paper reviews the articles of the value chain and business model of m-commerce to disclosure the importance of business model innovation to mobile operators in the m-commerce value network. Since there is little consensus on how to conduct business model innovation, this thesis suggests that it can be expressed as a combination of three basic types of innovation. And introduce a new value generating business model based on ADC/MAS model of China mobile provide to enterprises with low/high penetration of information.
Design of a fully-digital class-D audio power amplifier based on open-loop configuration

A fully-digital open-loop class-D audio power amplifier is presented. By using the proposed error feedback structure, the ΔΣ noise shaper reduces the word length of the input signal while maintaining its precision. An optimized compensation algorithm based on 2x interpolation linearization is proposed to improve the total harmonic distortion (THD), as well as to reduce its hardware overhead. The whole system has been implemented in the standard SMIC 0.18μm 1P6M Logic Salicide process. The test results show that the system achieves a maximal SNDR of 82.9dB and a dynamic range of 83.7dB with a power consumption of 0.12mW under a supply voltage of 1.8V, which is suitable for the application of high-fidelity audio systems.
Variational method for computing surface acoustic pressure on vibrating bodies, applied to transversely oscillating disks

A variational principle derived from the Kirchhoff-Helmholtz integral relation can be applied to acoustic radiation and diffraction problems. An illustrative example discussed here is that of sound radiation from a flat rigid circular disk in transverse oscillation. The variational formulation has the surface pressure as the unknown variable, with the normal velocity of the surface taken as given. The Rayleigh-Ritz method used in determining approximate solutions in terms of truncated expansions of basis functions encounters some numerical problems in the evaluation of integrals with singular integrands. The integrands are nevertheless integrable and techniques are described for handling the singularities. Another potential source of difficulty is that the tangential derivative of the surface pressure for the exact solution must be infinite at the edge of the disk. One makes use of prior knowledge of such a fact by using basis functions with the correct dependence on radial distance near the disk edge. Because basis functions in the Rayleigh-Ritz procedure have been selected with the aid of prior insight into the nature of the true solution, accurate results are obtained with a relatively small number of basis functions. The numerical solutions agree well with results calculated by Leitner in 1949.
Integration of Diverse Data Sources for Spatial PM2.5 Data Interpolation

Heterogeneous data fusion from disparate geospatial sensors has drawn increasing attention in multimedia. Unfortunately, environmental sensors are usually sparsely and preferentially located, which restricts situation recognition of geographical regions and results in uncertainty in derived inferences. Spatial interpolation is an effective way to solve the problem of data sparsity, which demands the availability of related data sources. However, these data sources are usually in different resolutions, distributions, scales, and densities, which poses a major challenge in data integration. To address this problem, we present a novel spatial interpolation framework to incorporate diverse data sources and model the spatial processes explicitly at multiple resolutions. Spectral analysis is deployed to generate features at multiple spatial resolutions and to improve the interpolation accuracy at unobserved locations. A statistical operator based on the spatial Gaussian process is implemented and integrated into a geospatial situation recognition system, which can analyze heterogeneous spatio-temporal data streams derived from sensors. To verify the effectiveness and efficiency of the proposed framework, this framework is applied to the PM2.5 air pollution application. Experiments conducted in California, USA, demonstrate that the proposed method outperforms state-of-the-art approaches.
DOA Estimation for Uniform Linear Array with Mutual Coupling

An algorithm is presented for direction-of-arrival (DOA) estimation in the presence of unknown mutual coupling based on the generalized eigenvalues utilizing signal subspace eigenvectors (GEESE) algorithm for uniform linear array (ULA). It is not an iterative algorithm, and a spectral peak search is not required. The DOA can be accurately estimated without any calibration sources since the effects of mutual coupling can be eliminated by the inherent mechanism of the proposed algorithm. An algorithm for estimating the mutual coupling coefficients is also proposed. Simulation results demonstrate the effectiveness of the proposed algorithms.