nils-herrmann/clean_scirepeval huggingface dataset:
Analytical design of PID controller for enhancing ride comfort of active vehicle suspension system

In this paper, a new design of proportional-integral-derivative (PID) controller for the active vehicle suspension system (AVSS) of a quarter car model is proposed on the basis of the well-known Internal Model Control (IMC) theory in order to compromise the two conflicting criteria between the passenger ride comfort and road handling. By using the given mathematical ordinary differential equations (ODEs) and state-space matrix expression in t-domain via the kinematic and dynamic of a quarter two degrees of freedom model, the transfer function is firstly established for its model and the proposed AVSS based PID control is then systematically introduced for enhancing the ride comfort. Moreover, the computer simulation model of the passive and active suspension systems is established for the purpose of having a fair comparison. A various kinds of the road input signals are selected for testing the systems, such as unit step, sine wave, and white noise signals. The simulation results indicate that the performance of proposed AVSS has the significantly improved in terms of reducing the peak overshoot of sprung mass displacement and sprung mass acceleration in compared with the other traditional passive suspension systems.
FPGA architecture of HMM-based decoder module in speech recognizer

This paper presents the reconfigurable architecture and implementation of HMM-based decoder module in speech recognizer on FPGA. The architecture is done with different parameters of speech recognition system that could be easily reconfigurable. The design and implementation on FPGA have been verified with utterances of 800 test speeches. The implementation results, the recognition accuracy results of up to 98% are also presented.
The generalized lapped biorthogonal transform

A lattice structure based on the singular value decomposition (SVD) is introduced. The lattice can be proven to use a minimal number of delay elements and to completely span a large class of M-channel linear phase perfect reconstruction filter banks (LPPRFB): all analysis and synthesis filters have the same FIR length of L=KM, sharing the same center of symmetry. The lattice also structurally enforces both linear phase and perfect reconstruction properties, is capable of providing fast and efficient implementation, and avoids the costly matrix inversion problem in the optimization process. From a block transform perspective, the new lattice represents a family of generalized lapped biorthogonal transforms (GLBT) with arbitrary integer overlapping factor K. The relaxation of the orthogonal constraint allows the GLBT to have significantly different analysis and synthesis basis functions which can then be tailored appropriately to fit a particular application. Several design examples are presented along with a high-performance GLBT-based progressive image coder to demonstrate the superiority of the new lapped transforms.
The variable-length generalized lapped biorthogonal transform

This paper introduces a class of linear phase lapped biorthogonal transforms with basis functions of variable length (VLGLBT). The transform can be characterized by a lattice which structurally enforces both linear phase and perfect reconstruction properties as well as provides a fast and efficient transform implementation. Our main motivation of the new transform is its application in image coding. The VLGLBT has several long overlapped basis functions for representing smooth signals to avoid blocking artifacts. The rest of the bases covering high-frequency bands are constrained to be short to limit ringing artifacts. The relaxation of the orthogonal constraint allows the VLGLBT to have significantly different analysis and synthesis banks which can be tailored appropriately to obtain high-quality reconstructed images. Most importantly, the variable-length property allows us to design very fast and low-complexity transforms. Comparing to the popular DCT, a fast VLGLBT named FLT only requires 6 more multiplications and 8 more additions. Yet, image coding examples show that the FLT is far superior than the DCT and is close to the 9/7-tap biorthogonal wavelet in both objective and subjective coding performance.
Adaptive Lagrange Multiplier Selection Using Classification-Maximization and Its Application to Chroma QP Offset Decision

In this paper, we propose bit allocation between luma samples and chroma samples using chroma quantization parameter (QP) offsets for Cb and Cr. For this work, we propose an efficient adaptive Lagrange multiplier selection method using classification-maximization, and then apply the proposed adaptive Lagrange multiplier selection to decide chroma QP offsets for Cb and Cr. To our knowledge, this is the first proposal to adaptively decide chroma QP offsets. Because the default mapping function between a chroma QP and a luma QP in H.264 is unbalanced at especially low QPs, the proposed chroma QP offset decision achieves improvement up to 0.8 dB from the experimental results.
Video compression using integer DCT

This paper describes the implementation of the integer discrete cosine transform (IntDCT) using the Walsh-Hadamard transform and the lifting scheme. The implementation is in the forms of shifts and adds, and all internal nodes have finite precision. A general-purpose scheme of 8-pt IntDCT with complexity of 45 adds and 18 shifts is proposed which gives comparable performance to the floating-point DCT (FloatDCT). For this particular scheme with 8-bit input, perfect reconstruction (PR) is preserved even when all the internal nodes are limited to 16-bit words, rendering the Pentium MMX optimization possible. Implementation has been done to incorporate the proposed IntDCT into the H.263+ coder, and the resulting system performs equally well as the original. Further extension to the MPEG coder is straightforward. The proposed IntDCT is reversible, with a low level of power consumption, and is very suitable for source coding, and communication, etc. in a mobile environment.
Leaky-wave slit antenna incorporated with a frequency selective surface for terahertz application

This paper presents the design of a leaky-wave slit antenna incorporated with a frequency selective surface (FSS) in a high-permittivity gallium arsenide (GaAs) substrate for terahertz applications at around 300 GHz. The narrow slit on the top side of the substrate is excited by a delta-gap voltage source at the center and acts as a perfect mirror, and the FSS with an array of circular holes printed on the bottom side of the substrate acts as a partially reflective mirror; thus it forms a Fabry-Perot resonator. The substrate thickness is essentially important to determine the resonance frequency, whereas the periodicity and the diameter of a hole influence the antenna gain and side lobe level of the far-field pattern. More importantly, the geometry of the FSS has to be designed in consideration of the mean effective permittivity of both inside and outside media of the cavity. For device realization, the substrate thickness of 350 μm was chosen from a commercially available GaAs wafer. The FSS was designed with an array of 9 × 9 holes and a periodicity of 330 μm for achieving maximum directivity and good radiation patterns. All results were calculated using the finite-integration timedomain simulator Microwave Studio by CST. The optimized antenna produced a maximum directivity of 18.1 dBi and a radiation efficiency of 61% at 318 GHz. Side lobe levels in two principal planes (E- and H-plane) were approximately -15.1 dB and -15.6 dB, respectively. The size of the antenna was 3.6 mm × 3.6mm × 0.35mm, approximately 3.8λo × 3.8λo × 0.37λo of a free-space wavelength at 318 GHz, which makes the proposed antenna compact, planar, and lightweight as compared with the substrate lens-coupled antenna design.
A Novel Approach to FRUC Using Discriminant Saliency and Frame Segmentation

Motion-compensated frame interpolation (MCFI) is a technique used extensively for increasing the temporal frequency of a video sequence. In order to obtain a high quality interpolation, the motion field between frames must be well-estimated. However, many current techniques for determining the motion are prone to errors in occlusion regions, as well as regions with repetitive structure. We propose an algorithm for improving both the objective and subjective quality of MCFI by refining the motion vector field. We first utilize a discriminant saliency classifier to determine which regions of the motion field are most important to a human observer. These regions are refined using a multistage motion vector refinement (MVR), which promotes motion vector candidates based upon their likelihood given a local neighborhood. For regions which fall below the saliency-threshold, a frame segmentation is used to locate regions of homogeneous color and texture via normalized cuts. Motion vectors are promoted such that each homogeneous region has a consistent motion. Experimental results demonstrate an improvement over previous frame rate up-conversion (FRUC) methods in both objective and subjective picture quality.
Using Phase and Magnitude Information of the Complex Directional Filter Bank for Texture Image Retrieval

This paper discusses how to utilize both magnitude and phase information obtained from the complex directional filter bank (CDFB) for the purpose of texture image retrieval. The relative phase, which is the difference of phases between adjacent CDFB coefficients, has a linear relationship with the angle of dominant orientation within a subband. This information is incorporated to form a new feature vector called CDFB-RP. Texture retrieval performance of the proposed CDFB-RP is compared to those of the conventional transforms including the Gabor wavelet, the contourlet transform, the steerable pyramid and the CDFB. With the same number of features, the CDFB-RP method outperforms all other transforms in texture image retrieval, while keeping lower complexity and computational time.
Comparison of DFT and cosine modulated filter banks in multicarrier modulation

This paper examines the comparative performance of DFT and cosine modulated filter banks used in multicarrier signaling over a linearly distorted channel, affected by both white Gaussian and NEXT noise. The interference caused by the overlap in the frequency responses of the signaling filters is calculated analytically and simulation results are given to support the theoretical calculations. It is shown that without any pre-receiver processing, the level of interchannel interference is lower in the cosine-modulated family of filters, because of their higher stopband attenuation. We also examine how pre-receiver processing (short equalizer plus cyclic prefix) can lower the level of interference, especially in the DFT system. Finally the capacity of a sample channel, similar to the twisted-pair channel of a subscriber loop, is calculated with and without the effect of interference taken into consideration.
View synthesis with hierarchical clustering based occlusion filling

This paper presents a depth image based rendering algorithm for view synthesis task. We address the challenging occlusion filling problem with a hierarchical clustering approach. Depth distribution of neighboring pixels around each occlusion is explored and from which we determine the number of surrounding depth planes with agglomerative clustering. Pixels in the most distant plane are picked as candidates to restore that occlusion. The proposed algorithm is evaluated on Middlebury stereo dataset and Microsoft Research 3D video dataset. Results show that our method ranks among the best performers.
Robust tracking and mapping with a handheld RGB-D camera

In this paper, we propose a robust method for camera tracking and surface mapping using a handheld RGB-D camera which is effective in challenging situations such as fast camera motion or geometrically featureless scenes. The main contributions are threefold. First, we introduce a robust orientation estimation based on quaternion method for initial sparse estimation. By using visual feature points detection and matching, no prior or small movement assumption is required to estimate a rigid transformation between frames. Second, a weighted ICP (Iterative Closest Point) method for better rate of convergence in optimization and accuracy in resulting trajectory is proposed. While the conventional ICP fails when there is no 3D features in the scene, our approach achieves robustness by emphasizing the influence of points that contain more geometric information of the scene. Finally, we show quantitative results on an RGB-D benchmark dataset. The experiments on an RGB-D trajectory benchmark dataset demonstrate that our method is able to track camera pose accurately.
Binary-to-Quaternary ASK Encoding in the Optical Domain With Semiconductor Optical Amplifiers

Quaternary amplitude-shift-keying signal is all-optically generated from binary signals exploiting gain compression in two semiconductor optical amplifiers. The scheme is suitable for phase-control-free all-optical digital-to-analog conversion. Only two semiconductor amplifiers, a single optical filter, and no assist probe light are required for 2-bit operation. In addition, the input wavelength is preserved at the output of the device. Dynamic operation is experimentally demonstrated. The quality of the level-converted signal is confirmed by the high Q -factor of the output eye diagrams.
Cumulative interference to aircraft radios from multiple portable electronic devices

Cumulative interference effects from portable electronic devices (PEDs) located inside a passenger cabin are conservatively estimated for aircraft radio receivers. PEDs' emission powers in an aircraft radio frequency band are first scaled according to their locations' interference path loss (IPL) values, and the results are summed to determine the total interference power. The multiple-equipment-factor (MEF) is determined by normalizing the result against the worst case contribution from a single device. Conservative assumptions were made and MEF calculations were performed for Boeing 737's Localizer, Glide-slope, Traffic Collision Avoidance System, and Very High Frequency Communication radio systems where full-aircraft IPL data were available. The results show MEF for the systems to vary between 10 and 14 dB. The same process was also used on the more popular window/door IPL data, and the comparison show the multiple-equipment-factor results came within one decibel (dB) of each other.
The eigenfilter for the design of linear-phase filters with arbitrary magnitude response

The author studies the design of linear-phase FIR (finite impulse response) digital filters to approximate linear-phase functions with arbitrary magnitude response. The design method is based on the computation of an eigenvector of an appropriate real, symmetric, and positive-definite matrix. The design of complex-coefficient linear-phase filters is shown to be an extension of the design of the real-coefficient filter. Several examples are presented which demonstrate the usefulness of the approach.<<ETX>>
Data pruning-based compression using high order edge-directed interpolation

This paper proposes a data pruning-based compression scheme to improve the rate-distortion relation of compressed images and video sequences. The original frames are pruned to a smaller size before compression. After decoding, they are interpolated to their original size by an edge-directed interpolation. The data pruning is optimized to obtain the minimal distortion in the interpolation phase. Furthermore, a novel high order interpolation is proposed to adapt the interpolation to many edge directions. This high order filtering uses extra surrounding pixels and achieves more robust edge-directed image interpolation. Simulation results are shown for both image interpolation and coding applications.
Real-Time Affine Global Motion Estimation Using Phase Correlation and its Application for Digital Image Stabilization

We propose a fast and robust 2D-affine global motion estimation algorithm based on phase-correlation in the Fourier-Mellin domain and robust least square model fitting of sparse motion vector field and its application for digital image stabilization. Rotation-scale-translation (RST) approximation of affine parameters is obtained at the coarsest level of the image pyramid, thus ensuring convergence for a much larger range of motions. Despite working at the coarsest resolution level, using subpixel-accurate phase correlation provides sufficiently accurate coarse estimates for the subsequent refinement stage of the algorithm. The refinement stage consists of RANSAC based robust least-square model fitting for sparse motion vector field, estimated using block-based subpixel-accurate phase correlation at randomly selected high activity regions in finest level of image pyramid. Resulting algorithm is very robust to outliers such as foreground objects and flat regions. We investigate the robustness of the proposed method for digital image stabilization application. Experimental results show that the proposed algorithm is capable of estimating larger range of motions as compared to another phase correlation method and optical flow algorithm.
Motion vector refinement for FRUC using saliency and segmentation

Motion-Compensated Frame Interpolation (MCFI) is a technique used extensively for increasing the temporal frequency of a video sequence. In order to obtain a high quality interpolation, the motion field between frames must be well-estimated. However, many current techniques for determining the motion are prone to errors in occlusion regions, as well as regions with repetitive structure. An algorithm is proposed for improving both the objective and subjective quality of MCFI by refining the motion vector field. A Discriminant Saliency classifier is employed to determine regions of the motion field which are most important to a human observer. These regions are refined using a multi-stage motion vector refinement which promotes candidates based on their likelihood given a local neighborhood. For regions which fall below the saliency threshold, frame segmentation is used to locate regions of homogeneous color and texture via Normalized Cuts. Motion vectors are promoted such that each homogeneous region has a consistent motion. Experimental results demonstrate an improvement over previous methods in both objective and subjective picture quality.
Low-order IIR filter bank design

The advantage of infinite-impulse response (IIR) filters over finite-impulse response (FIR) ones is that the former require a much lower order (much fewer multipliers and adders) to obtain the desired response specifications. However, in contrast with well-developed FIR filter bank design theory, there is no satisfactory methodology for IIR filter bank design. The well-known IIR filters are mostly derived by rather heuristic techniques, which work in only narrow design classes. The existing deterministic techniques usually lead to too high order IIR filters and thus cannot be practically used. In this paper, we propose a new method to solve the low-order IIR filter bank design, which is based on tractable linear-matrix inequality (LMI) optimization. Our focus is the quadrature mirror filter bank design, although other IIR filter related problems can be treated and solved in a similar way. The viability of our theoretical development is confirmed by extensive simulation.
Two-channel perfect-reconstruction FIR QMF structures which yield linear-phase analysis and synthesis filters

Two perfect-reconstruction structures for the two-channel quadrature mirror filter (QMF) bank, free of aliasing and distortions of any kind, in which the analysis filters have linear phase, are described. The structure in the first case is related to the linear prediction lattice structure. For the second case, new structures are developed by propagating the perfect-reconstruction and linear-phase properties. Design examples, based on optimization of the parameters in the lattice structures, are presented for both cases.
On factorization of M-channel paraunitary filterbanks

We systematically investigate the factorization of causal finite impulse response (FIR) paraunitary filterbanks with given filter length. Based on the singular value decomposition of the coefficient matrices of the polyphase representation, a fundamental order-one factorization form is first proposed for general paraunitary systems. Then, we develop a new structure for the design and implementation of paraunitary system based on the decomposition of Hermitian unitary matrices. Within this framework, the linear-phase filterbank and pairwise mirror-image symmetry filterbank are revisited. Their structures are special cases of the proposed general structures. Compared with the existing structures, more efficient ones that only use approximately half the number of free parameters are derived. The proposed structures are complete and minimal. Although the factorization theory with or without constraints is discussed in the framework of M-channel filterbanks, the results can be applied to wavelets and multiwavelet systems and could serve as a general theory for paraunitary systems.
Rate estimation via maximum likelihood parameter estimation: Application in fast mode-selection within the H.264/AVC

In this paper a novel method to estimate the required bits for representing the coded (quantized) coefficients within a block of natural video sequences is proposed. The proposed method assumes a parameterized probabilistic model for coded data and utilizes a maximum likelihood parameter estimation technique to estimate the model's parameters. The proposed method achieves a robust estimation of the rate based on the estimated probability of each coefficient based on zero order entropy. The rate estimation via maximum likelihood parameter estimation enjoys lower computational complexity, compared to the actual entropy coding of the data. For the purpose of rate estimation we consider a number of options to estimate the parameters of the probabilistic model of coded data. In the context optimal mode selection within the H.264/AVC video codec, the rate estimation method is used to estimate a Lagrangian rate-distortion cost which would be minimized for the optimal mode. The experimental results show that the proposed method considerably reduces the computational complexity while maintaining almost the same rate-distortion coding efficiency compared to mode selection using the actual rate.
Analysis and Design of Cost-Effective, High-Throughput LDPC Decoders

This paper introduces a new approach to cost-effective, high-throughput hardware designs for low-density parity-check (LDPC) decoders. The proposed approach, called nonsurjective finite alphabet iterative decoders (NS-FAIDs), exploits the robustness of message-passing LDPC decoders to inaccuracies in the calculation of exchanged messages, and it is shown to provide a unified framework for several designs previously proposed in the literature. NS-FAIDs are optimized by density evolution for regular and irregular LDPC codes, and are shown to provide different tradeoffs between hardware complexity and decoding performance. Two hardware architectures targeting high-throughput applications are also proposed, integrating both Min-Sum (MS) and NS-FAID decoding kernels. ASIC post synthesis implementation results on 65-nm CMOS technology show that NS-FAIDs yield significant improvements in the throughput to area ratio, by up to 58.75% with respect to the MS decoder, with even better or only slightly degraded error correction performance.