nils-herrmann/clean_scirepeval huggingface dataset:
Comparative study of stripline dipole antenna on semiinfinite and lens substrates at terahertz frequency

The input impedance and radiation characteristics of a stripline dipole antenna on different substrate schemes are presented. Two radiation environments, a semi-infinite galliumarsenide substrate (hereafter called a “semi-infinite substrate”) and a thin gallium-arsenide substrate backed by a silicon lens (hereafter a “lens substrate”), were examined, and the antenna performances were analyzed in a broad frequency range up to 5.0 THz. The semi-infinite substrate approach is useful in the initial investigation of the antenna characteristic itself while saving a significant amount of computational time. The study provides good guidelines for the design of a terahertz photoconductive antenna in that the antenna effect and the lens substrate effect can be individually characterized and optimized for the best possible performance.
Lapped transform domain denoising using hidden Markov trees

Algorithms based on wavelet-domain hidden Markov tree (HMT) have demonstrated excellent performance for image denoising. The HMT model is able to capture image features across the scales, in contrast to classical shrinkage that thresholds subbands independently. In this work, we extend the aforementioned results to a lapped transform domain. Lapped transforms (LT) are M-channel linear phase filter banks. Their use is motivated by their good energy compaction properties and robustness to oversmoothing. It is also observed that LT preserve better oscillatory image components, such as textures. Since LT are applied as block transforms, the transforms coefficients are rearranged into an octave-like decomposition, and their statistics are modeled by the same HMT structure as in the wavelet case. At moderate noise levels, the proposed algorithm is able to improve the results obtained with wavelets, subjectively and objectively.
Perceptual Video Coding with H.264

In this paper a novel approach to perceptual video coding is presented for block-based video coders. This is done by replacing purely mathematical models for measuring the distortion in video quality, such as mean squared error (MSE) or mean absolute difference (MAD), with a distortion model that measures the perceived distortion by an average human observer. Additionally, to keep the computational complexity of perceptual measurements reasonably low, the suggested model uses the structural properties of the underlying video coder to calculate the suggested perceptual distortion. It's shown that the distortion measure based on the suggested model can be utilized for different rate-distortion optimized video coding techniques such as mode selection and rate control
Symmetric Orthogonal Complex-Valued Filter Bank Design by Semidefinite Programming

A new design method for complex-valued two-channel finite impulse response (FIR) filter banks with both orthogonality and symmetry properties is developed. Based on a novel linear matrix inequality (LMI) characterization of trigonometric curves, the optimal design of perfect-reconstruction filter banks is cast into a semidefinite programming (SDP) problem. The dimension of the resulting SDP problem is further reduced by exploiting convex duality. Consequently, the globally optimal solution can be found for any practical filter length and desired regularity order.
Oversampled linear-phase perfect reconstruction filter banks with higher-order feasible building blocks: Structure and parameterization

This paper proposes new building blocks for the lattice structure of oversampled linear-phase perfect reconstruction filter banks (OLPPRFBs). The structure is an extended version of higher-order feasible building blocks for critically-sampled LPPRFBs. It uses fewer number of building blocks and design parameters than those of traditional OLPPRFBs, whereas the frequency characteristic of the new OLPPRFB is comparable to that of traditional one.
Linear phase paraunitary filter banks: theory, factorizations and designs

M channel maximally decimated filter banks have been used in the past to decompose signals into subbands. The theory of perfect-reconstruction filter banks has also been studied extensively. Nonparaunitary systems with linear phase filters have also been designed. The authors study paraunitary systems in which each individual filter in the analysis synthesis banks has linear phase. Specific instances of this problem have been addressed by other authors, and linear phase paraunitary systems have been shown to exist. This property is often desirable for several applications, particularly in image processing. They begin by answering several theoretical questions pertaining to linear phase paraunitary systems. Next, they develop a minimal factorization for a large class of such systems. This factorization will be proved to be complete for even M. Further, they structurally impose the additional condition that the filters satisfy pairwise mirror-image symmetry in the frequency domain. This significantly reduces the number of parameters to be optimized in the design process. They then demonstrate the use of these filter banks in the generation of M-band orthonormal wavelets. Several design examples are also given to validate the theory.
Motion wavelet difference reduction (MWDR) video codec

In this paper, a new fast video codec using Wavelet Difference Reduction (WDR) algorithm is presented. This proposed video codec is inspired by the concept of motion JPEG; namely, we adapted the efficient WDR still image compression algorithm into a video compression algorithm without the motion estimation step. This approach significantly reduces the processing time for motion vector search and motion compensation procedures. In addition, we employ block-based WDR algorithm which significantly reduces the memory requirement while comparing to other wavelet based compression algorithm.
Accurate Lithium-ion battery parameter estimation with continuous-time system identification methods

The modeling of Lithium-ion batteries usually utilizes discrete-time system identification methods to estimate parameters of discrete models. This paper adopts direct continuous-time system identification methods to estimate the parameters of equivalent circuit models for Lithium-ion batteries. Compared with discrete-time system identification methods, the continuous-time system identification methods provide more accurate estimates to both fast and slow dynamics in battery systems and are less sensitive to perturbations. A case of a 2nd-order equivalent circuit model is studied which shows that the continuous-time estimates are more robust to high sampling rates, measurement noises and rounding errors. Simulation and experiment results validate the analysis and demonstrate the superiority of the continuous-time system identification methods in battery applications.
Adaptive Image Denoising by Mixture Adaptation

We propose an adaptive learning procedure to learn patch-based image priors for image denoising. The new algorithm, called the expectation-maximization (EM) adaptation, takes a generic prior learned from a generic external database and adapts it to the noisy image to generate a specific prior. Different from existing methods that combine internal and external statistics in ad hoc ways, the proposed algorithm is rigorously derived from a Bayesian hyper-prior perspective. There are two contributions of this paper. First, we provide full derivation of the EM adaptation algorithm and demonstrate methods to improve the computational complexity. Second, in the absence of the latent clean image, we show how EM adaptation can be modified based on pre-filtering. The experimental results show that the proposed adaptation algorithm yields consistently better denoising results than the one without adaptation and is superior to several state-of-the-art algorithms.
Inter-Layer Motion Vector Interpolation for Low-Complexity and Very Low Bitrate Scalable Video Coding

A low-complexity and very low bitrate scalable video coding scheme is proposed in this paper. The proposed scheme consists of a novel weighted smoothing method and a novel interpolation mode map method to efficiently interpolate motion vectors between layers. The weighted smoothing method gives smoother motion vector field by considering the motion boundaries through motion vector correlation. In the mode map method, four inter-layer motion vector interpolation methods are combined to generate the best interpolated motion vector field. The mode map indicates which interpolation method is chosen for a particular block. Simulation results show the effectiveness of the proposed method compared to the traditional motion vector repeating method. The motion compensated frames that are generated using the proposed scheme provide improved results both in terms of PSNR values and visual quality.
A new method in FIR filter design

Recently a method in FIR filter design using cosine modulation was proposed. Given a prototype M-th band lowpass filter with cutoff frequency at /spl tau//M, one can obtain a new filter with comparable frequency characteristics with rational cutoff frequency. In this paper, we extend the theory to the case of arbitrary cutoff frequency. The resulting method corresponds to finding the equivalent window impulse response which generates the filters. Simulation result shows that passband ripple, stopband attenuation, and transition bandwidth of the resulting filter are approximately the same as those in the original one. The quantization effect is also discussed.
A new combination of 1D and 2D filter banks for effective multiresolution image representation

In this paper, an effective multiresolution image representation using the combination of 2D quincunx filter bank (FB) and directional wavelet transform (WT) is presented. The proposed method yields simple implementation and low calculation costs compared to the other 1D and 2D FB combinations or adaptive directional WTs. Furthermore, it is a nonredundant transform and realizes quad-tree like multiresolution representation. In applications on nonlinear approximation and image coding, the proposed filter bank shows visual quality improvements and has higher PSNR.
Passenger transmitters as a possible cause of aircraft fuel ignition - in support of an aircraft accident investigation

An investigation was performed to study the potential for radio frequency (RF) power radiated from transmitting Portable Electronic Devices (PEDs) to create an arcing/sparking event within the fuel tank of a large transport aircraft. A survey of RF emissions from typical intentional transmitting PEDs was first performed. Aircraft measurements of RF coupling to the fuel tank and its wiring were also performed to determine the PEDs induced power on the wiring, and the re-radiated power within the fuel tank. Laboratory simulations were conducted to determine the required RF power level for an arcing/sparking event. Data analysis shows large positive safety margins, even with simulated faults on the wiring.
PPIQ: A probabilistic framework for Image Quality Assessment

In this paper a framework for Image Quality Assessment (IQA) is introduced based on the properties of Receptive Fields (RFs) which are the primary mechanism for detection of visual patterns in the Human Visual System (HVS). The proposed framework offers a probabilistic approach to the perceptual IQA, based on the probability of detecting discrepancies (distortion) between the corresponding features of a test and a reference image. The proposed Probabilistic Perceptual Image Quality (PPIQ) framework facilitates defining specific perceptual metrics for specific applications. To give an example on how the PPIQ framework can be utilized to define an Image Quality Metric (IQM), a sample IQM is introduced based on the properties of simple RFs of the early vision in the HVS. The sample IQM, based on the PPIQ framework, exhibits comparable accuracy to that of the legacy methods in terms of predicting the outcome of subjective image quality experiments.
Efficient Large-Scale Filter/Filterbank Design via LMI Characterization of Trigonometric Curves

Many filter and filterbank design problems can be posed as the optimization of linear or convex quadratic objectives over trigonometric semi-infinite constraints. Recent advances in design methodology are based on various linear matrix inequality (LMI) characterizations of the semi-infinite constraints, and semidefinite programming (SDP) solutions. Despite these advances, the design of filters of several hundredth order, which typically arise in multicarrier communication and signal compression, cannot be accommodated. This hurdle is due mainly to the large number of additional variables incurred in the LMI characterizations. This paper proposes a novel LMI characterization of the semi-infinite constraints that involves additional variables of miminal dimensions. Consequently, the design of high-order filters required in practical applications can be achieved. Examples of designs of up to 1200-tap filters are presented to verify the viability of the proposed approach.
Image/video scaling algorithm based on multirate signal processing

This paper presents an approach for image and video scaling using multirate signal processing. The main objective is to scale images with an arbitrary rational scaling ratio without visible aliasing or distortion artifact. The approach can be applied to grey scale images, color images and video signals in both spatial domain and time domain. Cosine modulation is used to minimize the required on-chip memory since only a prototype filter is stored with some cosine modulation factors. The filters are shown to have comparable regularity for each scaling factor. An efficient structure is proposed for limited bit length filter coefficients which has no imaging artifact after the filter coefficients are quantized. Simulations on still image and video scaling are presented.
Motion vector processing for frame rate up conversion

In this paper, the effect of motion vector accuracy on the efficiency of motion compensated frame rate up conversion (MC-FRUC) is studied. The motion vector processing problem is formulated and analyzed via motion vector modelling. A processing scheme is proposed to improve the interpolated frame quality at the decoder. The practical application of integrating the motion vector processing algorithm in a standard H.263 decoder for MC-FRUC is also discussed. Experimental results show that a 0.4-0.6 dB gain in the H.263 codec, and a 0.5-2 dB gain in off-line frame rate conversion can be obtained by the proposed algorithm.
Design of Exactly Linear Phase  $K$-Regular IIR Half-Band Filter

This paper proposes a novel method to design exactly linear phase infinite impulse response half-band filters with arbitrary regularity. Broadly speaking, the design problem is formulated as a semi-infinite program, which is then turned into a semidefinite program of minimal order via a new linear matrix inequality characterization of convex hulls of trigonometric polynomials. In contrast to maximally flat approach, the proposed method allows direct control of various design parameters, which in turn enables the synthesis of filters with better transition response. The viability of the proposed method is demonstrated through several numerical examples.
Contourlet Domain Multiband Deblurring Based on Color Correlation for Fluid Lens Cameras

Due to the novel fluid optics, unique image processing challenges are presented by the fluidic lens camera system. Developed for surgical applications, unique properties, such as no moving parts while zooming and better miniaturization than traditional glass optics, are advantages of the fluid lens. Despite these abilities, sharp color planes and blurred color planes are created by the nonuniform reaction of the liquid lens to different color wavelengths. Severe axial color aberrations are caused by this reaction. In order to deblur color images without estimating a point spread function, a contourlet filter bank system is proposed. Information from sharp color planes is used by this multiband deblurring method to improve blurred color planes. Compared to traditional Lucy-Richardson and Wiener deconvolution algorithms, significantly improved sharpness and reduced ghosting artifacts are produced by a previous wavelet-based method. Directional filtering is used by the proposed contourlet-based system to adjust to the contours of the image. An image is produced by the proposed method which has a similar level of sharpness to the previous wavelet-based method and has fewer ghosting artifacts. Conditions for when this algorithm will reduce the mean squared error are analyzed. While improving the blue color plane by using information from the green color plane is the primary focus of this paper, these methods could be adjusted to improve the red color plane. Many multiband systems such as global mapping, infrared imaging, and computer assisted surgery are natural extensions of this work. This information sharing algorithm is beneficial to any image set with high edge correlation. Improved results in the areas of deblurring, noise reduction, and resolution enhancement can be produced by the proposed algorithm.
Nonlinear control of DFIG under symmetrical voltage dips with demagnetizing current solution

In this research, the novel hysteresis current controller in dq reference frame is proposed to replace the traditional Proportional-Integral (PI) regulator in the vector control scheme of Doubly Fed Induction Generator (DFIG). More dominant than conventional hysteresis current controller, this algorithm can modulate the voltage space vector directly in the dq rotation frame. Therefore, it is simple to employ the new method in the vector control scheme of DFIG. In addition, it can be used in demagnetizing current control scheme to ride through the grid voltage disturbances. The simulation results demonstrated the very fast dynamic responses of power control and the ride through capability of this method under voltage dips.
Hybrid Terminal Sliding Mode Control and quadrotor's vision based ground object tracking

In this paper, we presents a systematic approach to the vision based ground object tracking problem of a low cost AR.Drone quadrotor, using Hybrid Terminal Sliding Mode Controller (HTSM), based on nonsingular terminal sliding mode (NTSM) and higher order sliding mode (HOSM). In this approach, NTSM manifold is used to provide fast convergence and better tracking precision while HOSM control law is utilized to eliminate chattering phenomenon. The Experimental results demonstrate that the proposed HTSM approach outperforms conventional PD and sliding mode tracking controllers in terms of response speed, tracking precision and robustness.
Kinematic Analysis and Development of Five-Axis Milling Machine Based on Parallel Mechanisms

Machine tools with parallel structures are the subject that usually discuss in many researches. Users are still largely unaware of the advantages offered by these new machine structures. This paper presents the development of a mathematical model describing the kinematics problem and analysis workspace of five-axis milling machine (FMM) based on six-degree-of-freedom (6DOF) structure. In addition, reachable workspace features and parameters optimization as criterion of the maximum of working volume for PM are considered.
Joint optimization of lattice vector quantizer and entropy coder for a Laplacian source

This paper presents a joint optimization algorithm for lattice vector quantization (LVQ) and entropy coding for a Laplacian source at all ranges of bit rates. Entropy-constrained lattice vector quantizers (ECLVQs) are often used in practical coding systems. In order to develop an ECLVQ design algorithm, we derive estimation expressions for both distortion and entropy. From these estimations, we develop an algorithm that jointly optimizes LVQ and the entropy coder pair for a given entropy rate. Compared to previously reported approaches, the approach reported quickly computes a highly accurate optimal ECLVQ at all ranges of bit rates. Since a Laplacian source represents a wide class of subband transformed data, the algorithm can be readily applied as a subband coding method. When the proposed algorithm is applied to a wavelet based image coding, the coding performance surpasses those of any previously reported subband coders, especially at low bit rates.
View synthesis based on Conditional Random Fields and graph cuts

We propose a novel method to synthesize intermediate views from two stereo images and disparity maps that is robust to errors in disparity maps. The proposed method computes a placement matrix from each disparity map that can be used to correct errors when warping pixels from reference view to virtual view. The second contribution is a new hole filling method that uses depth, edge, and segmentation information to aid the process of filling disoccluded pixels. The proposed method selects pixels from segmented regions that are connected to the disoccluded region as candidates to fill the disoccluded pixels. We also provide an explicit probabilistic model to select the best candidate for each disoccluded pixel efficiently with Conditional Random Fields (CRFs) and graph-cuts.
A Non-Isotropic Parametric Model for Image Spectra

Image restoration and enhancement problems are often considered using a solution based on a model for the image's power spectral density (PSD). This paper considers a new PSD model for images through modification of a previously considered isotropic model. The new model and an algorithm for estimating its parameters are presented. Several simulations considering PSD estimation for images corrupted by additive noise, distortion, and resolution reduction are presented to demonstrate the improvements made with this new modelling approach
Filter bank-based processing of the stress ECG

The algorithm presented is based on subband processing of the electrocardiogram (EGG), using Filter Banks (FB), and removes noise from stress-type ECGs. For Gaussian noise the FB-based method improves the signal-to-noise ratio (SNR), significantly better than the Mean and Median averaging methods. For muscle noise the FB-based method improves the SNR comparatively better than the Mean and Median averaging methods. The FB-based algorithm offers a way to process specific time periods in the heart beat cycle and remove noise in specific frequency bands.
All Optical Add and Drop Multiplexing Node for Hybrid Topology Networks

A new concept for all optical add and drop multiplexing (OADM) node is presented. The node is meant to act as gateway node between optical network segments that exhibit diverse properties in terms of multiplexing systems, granularity and modulation formats. The general architecture of the mentioned OADM node is presented, showing that the node is able to act as a “language translator” between network segments based on OTDM and WDM systems exploiting different modulation formats to transport data streams (RZ-OOK and NRZ-DPSK respectively). The design and experimental demonstration of a first prototype of an OADM node that is able to convert a NRZ-DPSK data signal coming from the WDM stream into a RZ-OOK signal, to drop one channel from the OTDM stream and insert the converted signal into the released time slot are presented.
Optimal motion compensated spatio-temporal filter for quality enhancement of H.264/AVC compressed video sequences

The paper proposes a novel algorithm to enhance the quality of H.264/AVC compressed video sequences by using an in-loop spatio-temporal motion compensated filter (MCSTF). Extra information from surrounding coded frames are used together with the information of the current coded frame to reduce the coding artifacts. With the availability of the original frame, the MCSTF coefficients are optimized at the encoder and then are implemented at the decoder. Furthermore, an overlapped motion compensated scheme is proposed to reduce the blocking artifacts from surrounding motion compensated frames. Simulation results are judged by PSNR and flickering metric.