nils-herrmann/clean_scirepeval huggingface dataset:
Azimuth-Keeping Characteristic Analysis and Computer Simulation for a Dynamically Tuned Gyro Based North-Finder

A characteristic of a north-finder applied in our project is that in experiments, its azimuth-keeping accuracy and the initial azimuth of the body on which the north-finder is fixed has a relation of the period function whose period is 180 degree. To find what causes this characteristic, the paper firstly introduces the principle of the dynamically tuned gyro based north-finder, then derives the differential equation about the influence of gyro drift upon the north-finder's azimuth-keeping accuracy. Based on this differential equation, several simulations are carried out to study how different sort of gyro drift influences the north-finder's azimuth-keeping accuracy. The comparisons of the simulation results with the experimental ones indicate that the gyro drift results in this characteristic. Ω is the axial rotation angular rate of the Earth along the Up (the local vertical) and it equals sin ie ω φ : ie ω is the axial rotation angular rate of the Earth and φ is the north-finder's latitude. This compensation scheme is rational because the north-finder is used in plain areas, and it is proved feasible by road test of the vehicle.
Slow light and omnidirectional resonances in the metamaterial-based multi-layer structures

Metamaterials, with effective negative permittivity and/or negative permeability, have paid much attention in recent years. We present the results on slow light and omnidirectional resonances in the metamaterial-based structures. We have found that the group velocity vanishes in the planar and cylindrical waveguides consisting of the left-handed metamaterial core and the single-negative-permittivity cladding. Ultra-low group velocity dispersion has been also found in such waveguides. On the other hand, we have found out omnidirectional resonances in various kinds of 1D photonic crystal heterostructures possessing the zero-phieff/zero-nmacr gap, and in a simple sandwich structure. The mechanisms of both phenomena have been revealed, and the properties of them have also been studied.
Research on Low Voltage Electrical Apparatus Switching Arc Image Gathering and Enhancement

Making use of arc image gathering system that base on high-speed picture frequency CCD technique, we proceed arc imagine gathering and analysis on CJX1-12/22 AC contactor. During high-speed arc image dynamic shoot process, it inevitably exists noise that coming from many aspects influencing image quality. The arc image analysis mainly concentrates on many aspects such as the motion forms and trend of arc image, the arc chute function of subsection arc extinction and so on. For this kind of special goal, it requests image's edge clear and can be distinguished in order to prominent the function and influence of arc imagepsilas contour. This paper first applies the adaptive median filter to eliminate stochastic noise, and then uses Laplacian sharpening to enhance the edge and the detail of image. The simulation result indicates that this method can effectively remove the noise and the prominent the contour.
Design and implementation of utility-based radio resource optimization using CAPRI

In this paper we introduce a utility-based optimization approach for wireless communication based on developed Common Application Requirement Interface (CAPRI). The proposed system allows applications to register their utility functions to a radio resource controller at run-time and in automatic way. This enables the implementation of utility-based optimization and run-time reconfiguration of applications. Specifically, in contrast to traditional utility-based optimization approaches that usually aim at optimizing a single application deployed for the entire system, our approach aims to generalize and express the requirements of multiple applications. To validate our proposed system, we have implemented a prototype of CAPRI using Windows platform. The implementation has been made publicly available under an open source license. We show that the overhead induced by the adoption of the CAPRI framework in terms of memory and processing requirements is small, and additional latencies induced by the framework are negligible. Further, a practical case study of multi-application utility-based optimization has been addressed and the results have been analyzed.
Why is image quality assessment so difficult?

Image quality assessment plays an important role in various image processing applications. A great deal of effort has been made in recent years to develop objective image quality metrics that correlate with perceived quality measurement. Unfortunately, only limited success has been achieved. In this paper, we provide some insights on why image quality assessment is so difficult by pointing out the weaknesses of the error sensitivity based framework, which has been used by most image quality assessment approaches in the literature. Furthermore, we propose a new philosophy in designing image quality metrics: The main function of the human eyes is to extract structural information from the viewing field, and the human visual system is highly adapted for this purpose. Therefore, a measurement of structural distortion should be a good approximation of perceived image distortion. Based on the new philosophy, we implemented a simple but effective image quality indexing algorithm, which is very promising as shown by our current results.
ETM+ Image Classification Research Based on Stratified and Regional Classification Method--Take Land-Use and Land-Cover in Shangri-La for Example

Beijing, China Abstract—Combine the stratified and regional thinking, we proposed a stratified and regional classification method that based on the spatial resolution fusion and NDVI, and utilized in the classification research of land-use and land-cover in Shangri- la. The method first used ETM+453 synthesized image, fused the panchromatic band to promote the spatial resolution, calculated NDVI after the extraction of related ground objects, then divided it into vegetation area and non-vegetation area, and classified the region separately with supervised classification. The results showed that this method, compared with the conventional supervised classification, the classification accuracy enhanced 12.94%.
Multiview Coding Mode Decision With Hybrid Optimal Stopping Model

In a generic decision process, optimal stopping theory aims to achieve a good tradeoff between decision performance and time consumed, with the advantages of theoretical decision-making and predictable decision performance. In this paper, optimal stopping theory is employed to develop an effective hybrid model for the mode decision problem, which aims to theoretically achieve a good tradeoff between the two interrelated measurements in mode decision, as computational complexity reduction and rate-distortion degradation. The proposed hybrid model is implemented and examined with a multiview encoder. To support the model and further promote coding performance, the multiview coding mode characteristics, including predicted mode probability and estimated coding time, are jointly investigated with inter-view correlations. Exhaustive experimental results with a wide range of video resolutions reveal the efficiency and robustness of our method, with high decision accuracy, negligible computational overhead, and almost intact rate-distortion performance compared to the original encoder.
Quality prediction of asymmetrically compressed stereoscopic videos

Objective quality assessment of stereoscopic 3D video is a challenging problem. We carry out a subjective test on symmetrically and asymmetrically compressed stereoscopic videos followed by different levels of low-pass filtering. We observe a strong systematic bias when using direct averaging of 2D video quality of both views to predict 3D video quality. We use a binocular rivalry inspired model to account for the prediction bias, leading to significantly improved quality estimation of stereoscopic videos. The model allows us to quantitatively predict the potential coding gain of asymmetric video compression, and provides new insight on the development of high efficiency 3D video coding schemes.
Information Content Weighting for Perceptual Image Quality Assessment

Many state-of-the-art perceptual image quality assessment (IQA) algorithms share a common two-stage structure: local quality/distortion measurement followed by pooling. While significant progress has been made in measuring local image quality/distortion, the pooling stage is often done in ad-hoc ways, lacking theoretical principles and reliable computational models. This paper aims to test the hypothesis that when viewing natural images, the optimal perceptual weights for pooling should be proportional to local information content, which can be estimated in units of bit using advanced statistical models of natural images. Our extensive studies based upon six publicly-available subject-rated image databases concluded with three useful findings. First, information content weighting leads to consistent improvement in the performance of IQA algorithms. Second, surprisingly, with information content weighting, even the widely criticized peak signal-to-noise-ratio can be converted to a competitive perceptual quality measure when compared with state-of-the-art algorithms. Third, the best overall performance is achieved by combining information content weighting with multiscale structural similarity measures.
Multi-Code MC-CDMA Using Joint CDTD and Inter-Code Interference Cancellation

In multicarrier code division multiple access (MC-CDMA), a good bit error rate (BER) performance can be achieved by using frequency-domain equalization (FDE) based on the minimum mean square error (MMSE) criterion. However, the presence of residual inter-code interference (ICI) after MMSE-FDE and despreading degrades the BER performance of the multi-code MC-CDMA. The use of ICI cancellation can improve the BER performance of the multi-code MC-CDMA. To further improve the BER performance, transmit diversity technique is effective. In this paper, cyclic delay transmit diversity (CDTD) is considered. CDTD can achieve the frequency diversity gain, whereas the well-known space-time transmit diversity (STTD) can achieve the antenna diversity gain owing to the space-time coding and provide a better BER performance than CDTD. It is shown in this paper that the performance degradation of CDTD is mainly due to the residual ICI after MMSE-FDE. In order to achieve a good BER performance, the multi-code MC-CDMA using joint CDTD and ICI cancellation is proposed, and its BER performance is evaluated by computer simulation.
Fair Packet Scheduling for Downlink Multiuser OFDM Systems with Channel and Queue Information

In this paper, an channel and queue aware fair (CQAF) packet scheduling scheme is proposed for the downlink packet transmission in multiuser orthogonal frequency division multiplexing (OFDM) systems. By making use of the infor- mation on the channel conditions and the queue lengths, the proposed CQAF packet scheduling scheme efficiently allocates the subcarriers, transmission power and modulation level to users under the constraints of total transmission power, the number of subcarriers, bit-error-rate (BER) requirement and generalized processor sharing (GPS)-based fairness requirement. The numerical results show that the proposed CQAF packet scheduling scheme can reduce the transmission delay and queue length significantly while maximizing system throughput and maintaining fairness among users.
Wavelet-based foveated image quality measurement for region of interest image coding

Region of interest (ROI) image and video compression techniques have been widely used in visual communication applications in an effort to deliver good quality images and videos at limited bandwidths. Most image quality metrics have been developed for uniform resolution images. These metrics are not appropriate for the assessment of ROI coded images, where space-variant resolution is necessary. The spatial resolution of the human visual system (HVS) is highest around the point of fixation and decreases rapidly with increasing eccentricity. Since the ROIs are usually the regions "fixated" by human eyes, the foveation property of the HVS supplies a natural approach for guiding the design of ROI image quality measurement algorithms. We have developed an objective quality metric for ROI coded images in the wavelet transform domain. This metric can serve to mediate the compression and enhancement of ROI coded images and videos. We show its effectiveness by applying it to an embedded foveated image coding system.
Analytical study of QAM with interference cancellation for high-speed multicode CDMA

In this paper, we consider the multilevel quadrature amplitude modulation (M-QAM) for forward link of multicode code-division multiple-access (CDMA) systems with interference cancellation to support high data rate service, and provide an analytical bit error rate (BER) performance of the system. In the current third-generation (3G) wide-band CDMA systems, in addition to multicode transmission, M-QAM is employed for high-speed downlink packet access (HSPDA) due to its high spectral efficiency. In frequency-selective fading channels, multipath interference seriously degrades the system performance, therefore interference cancellation technique is employed at the receiver. In this paper, an analytical closed-form BER of multicode CDMA systems with QAM is presented, where two important factors (channel estimation error and additive interference) on system performance are considered. Numerical results show that the system is very sensitive to additive multipath interference. With the help of interference cancellation technique, M-QAM can be adaptively employed in high signal-to-noise ratio cases to increase system throughput, within 5 MHz bandwidth. Meanwhile, simulation results are shown to illustrate the accuracy of the analytical method. Moreover, it is found that extra pilot power should be invested for more accurate channel estimation and consequently better BER performance when using the interference cancellation technique.
Double auction based spectrum sharing for wireless operators

As the traffic grows rapidly in wireless communication, the spectrum becomes scarce. The current inefficient fixed spectrum allocation schemes will not satisfy the growing spectrum demand. This paper proposes a double auction based dynamic spectrum sharing scheme for multiple operators adopting OFDMA in the downlink. More specifically, this scheme allows free subcarriers trading between operators to improve the efficiency of the spectrum utilization. In contrast with conventional auction, double auction deals with a “multiple seller and multiple buyer” case, which is more general in inter-operator spectrum sharing. In the proposed scheme, the sellers and buyers estimate the value of the subcarriers first. Then they submit their asks (bids) to the auctioneer based on their valuations. Bidding and asking strategy in a practical framework is proposed as well. Finally, two double auction methods are examined in the simulation.
Reduced-Reference Image Quality Assessment by Structural Similarity Estimation

Reduced-reference image quality assessment (RR-IQA) provides a practical solution for automatic image quality evaluations in various applications where only partial information about the original reference image is accessible. In this paper, we propose an RR-IQA method by estimating the structural similarity index (SSIM), which is a widely used full-reference (FR) image quality measure shown to be a good indicator of perceptual image quality. Specifically, we extract statistical features from a multiscale multiorientation divisive normalization transform and develop a distortion measure by following the philosophy in the construction of SSIM. We find an interesting linear relationship between the FR SSIM measure and our RR estimate when the image distortion type is fixed. A regression-by-discretization method is then applied to normalize our measure across image distortion types. We use six publicly available subject-rated databases to test the proposed RR-SSIM method, which shows strong correlations with both SSIM and subjective quality evaluations. Finally, we introduce the novel idea of partially repairing an image using RR features and use deblurring as an example to demonstrate its application.
Surface Reconstruction in Gradient-Field Domain Using Compressed Sensing

Surface reconstruction from measurements of spatial gradient is an important computer vision problem with applications in photometric stereo and shape-from-shading. In the case of morphologically complex surfaces observed in the presence of shadowing and transparency artifacts, a relatively large dense gradient measurements may be required for accurate surface reconstruction. Consequently, due to hardware limitations of image acquisition devices, situations are possible in which the available sampling density might not be sufficiently high to allow for recovery of essential surface details. In this paper, the above problem is resolved by means of derivative compressed sensing (DCS). DCS can be viewed as a modification of the classical CS, which is particularly suited for reconstructions involving image/surface gradients. In DCS, a standard CS setting is augmented through incorporation of additional constraints arising from some intrinsic properties of potential vector fields. We demonstrate that using DCS results in reduction in the number of measurements as compared with the standard (dense) sampling, while producing estimates of higher accuracy and smaller variability as compared with CS-based estimates. The results of this study are further supported by a series of numerical experiments.
Half-sine and triangular despreading chip waveforms for coherent delay-locked tracking in DS/SS systems

The performance of a coherent delay-locked tracking scheme for direct-sequence/spread-spectrum systems using half-sine or triangular chip waveforms for early and late despreading sequences is analyzed. The effect of band-limiting on the received signals is considered. Mean time to lose lock (MTLL) and root mean square (rms) tracking error of the delay-locked loop (DLL) are compared with that of a conventional DLL which uses rectangular chip despreading waveforms. Linear and nonlinear (based on the renewal process approach) analyses are employed to evaluate the performance of the DLL. Results show that the use of either the half-sine or triangular chip waveform reduces the rms tracking error and increases the MTLL considerably when the early-late spacing is approximately between 0.7-1.3 chip times. The results apply in particular to the commonly used DLL using one chip early-late spacing. Computer simulation for band-limited signals confirms the analytical results. The use of these despreading chip waveforms also reduces tracking offset in multipath environments.
Nanopatterning and bandgap grading to reduce defects in CdTe solar cells

We present simulation and experimental results proving the feasibility of a novel concept to increase efficiency of CdTe based solar cells. In order to achieve $0.50/W price in CdTe based modules, higher efficiencies need to be attained. The high defect density due to lattice-mismatch between CdS and CdTe reduces lifetime, voltage, and efficiency of the cells. We propose the use of a graded composition structure and a patterned substrate to reduce defects, increase lifetime, and efficiency of the cells. Innovative simulations using high-fidelity molecular dynamics predict that defect-free films are possible if the CdTe film is graded with Zn and is constructed as nano-islands with sizes below 90 nm. Both graded structure and nano-islands reduce the lattice-mismatch stresses. Also, the graded composition creates a back surface field and an enhanced ohmic contact. We have attempted to grow ZnTe and CdTe films on CdS substrates using a template of micro and nano-islands. Selective growths on patterned substrates have shown fewer grain boundaries when the island size decreases below 300 nm. Also, larger grain sizes were obtained using a CdTe/ZnTe stack when compared to a single layer CdTe. The simulation and experimental results demonstrate for the first time the ability to use nanopatterned substrates to enhance uniformity in thin film solar cells.
Research on Real Estate Early Warning System Based on Decision Tree and Fuzzy Recognition Theory

This paper presents a pre-warning system developed to monitor and provide pre-warning to the governmental decision makers in real estate market, applying the grey relational analysis and model design method, with the fuzzy recognition theory based on decision tree and its effectiveness. The real estate early warning system has been designed successfully by the three sub-modules of feature selection on each non-terminating node, decision rule on each non-terminating node and a new fuzzy decision tree method, early warning for the real estate market. The article details analysis and recognition module, a set of factors are selected by grey relational analysis and fuzzy recognition early-warning method is used, which can monitor the real estate property market, is developed. Empirical results indicate that the pre-warning system can provide useful information to regulate the property market.
Performance Analysis on Maximum Likelihood Detection for Two Input Multiple Output Systems

This paper addresses the problem of performance analysis for maximum likelihood (ML) detection in two-input multiple-output multiplexing systems. A novel analytical method is presented to formulate the symbol error probability (SEP). Based on the total probability theory, the SEPs of the two transmitted signals are obtained in closed-form by solving the SEP equations. Both equal and unequal power allocations are investigated. The accuracy of the proposed method is verified by Monte-Carlo simulations. The proposed method can also be extended to systems with more than two inputs.
Numerical simulation on novel nano-scale lateral double-gate tunneling field effect transistor

A novel nano-scale lateral double-gate tunneling field effect transistor (LDG-TFET) is proposed in this paper and its performance is shown through two dimensional device numerical simulations. The study result demonstrates that this new tunneling transistor allows for the steeper sub-threshold swings, e.g. below 60 mV/Dec, the super low supply voltage, e.g. operable at VDD ≪0.2V and the high ratio between the turn-on and turn-off current for the availability of high-k/metal stack materials. This tunneling field effect transistor may be integrated with present CMOS process and architecture with some specific applications such as memories because of the low turn-off current and when the delay is truly determined by interconnects because of its high turn-on/turn off ratio, which are important for next generation of micro-power and ultra-low integrated circuits.
Polyview Fusion: A Strategy to Enhance Video-Denoising Algorithms

We propose a simple but effective strategy that aims to enhance the performance of existing video denoising algorithms, i.e., polyview fusion (PVF). The idea is to denoise the noisy video as a 3-D volume using a given base 2-D denoising algorithm but applied from multiple views (front, top, and side views). A fusion algorithm is then designed to merge the resulting multiple denoised videos into one, so that the visual quality of the fused video is improved. Extensive tests using a variety of base video-denoising algorithms show that the proposed PVF method leads to surprisingly significant and consistent gain in terms of both peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) performance, particularly at high noise levels, where the improvement over state-of-the-art denoising algorithms is often more than 2 dB in PSNR.