nils-herrmann/clean_scirepeval huggingface dataset:
Power-Efficient Algorithms for Fourier Analysis over Random Wireless Sensor Network

Reduced execution time and increased power efficiency are important objectives in the distributed execution of collaborative signal processing tasks over wireless sensor networks. The power-efficient implementation of the Fourier transform computation is an exemplar of distributed data communication and processing task widely used in the signal processing field. Past work has presented some energy-efficient in-network Fourier transform computation algorithms devised only for uniformly sampled one-dimensional (1D) sensor data. However the circumstance that sensors are randomly distributed over a 2D plane may be more practical, therefore the conventional two-dimensional Fast Fourier Transform (2D FFT) defined for data sampled on uniform grids is not directly applicable in such environments. We address this problem by designing a distributed hybrid structure consisting of local Nonequispaced Discrete Fourier Transform (NDFT) and global FFT computation. Firstly, NDFT method is applied in a suitable choice of clusters to get the initial uniform Fourier coefficients with allowable estimation error bounds. We experiment with classical linear as well as generalized interpolation methods to compute NDFT coefficients within each cluster. A separable 2D FFT is then performed over all these clusters by employing our proposed energy-efficient 1D FFT computation that reduces communication costs using a novel bit index mapping strategy for data exchanges between sensors. The proposed techniques are implemented in a SID net-SWANS platform to investigate the communication costs, execution time, and energy consumption. Our results show reduced execution time and improved energy consumption when compared with existing work.
Acuurate segmentation of retina nerve fiber layer in OCT images

The quantification of intra-retinal boundaries in the Optical Coherence Tomography (OCT) is a crucial task to study and diagnose neurological and ocular diseases. Since the manual segmentation of layers is usually a time consuming task and relies on the user, an excessive volume of research has been done to do this job automatically and without interference of the user. Although, generally the same procedure is applied to extract all layers, but finding the RNFL is typically more challenging due to the fact that it may vanish in some parts of the eye, especially close to the fovea. To have general software, besides using common methods such as applying the shortest path algorithm on the global gradient of an image, some extra steps have been taken here to narrow the search area for Dijstra's [8] algorithm, especially for the second boundary. The result demonstrates high accuracy in segmenting the RNFL that is really important for the diagnosing Glaucoma.
Low-Complexity Video Compression Combining Adaptive Multifoveation and Reuse of High-Resolution Information

The phenomenon of reduced spatial resolution perceived away from the point of gaze (foveation point) in a scene by the human visual system can be gainfully exploited in image and video compression. Interest has recently evolved from single foveation points to dynamic and multiple points of foveation, implementing which entails significantly increased complexity in the encoder. In this paper, a novel idea of efficiently combining adaptive multipoint foveation with salvaged high-resolution information for reuse in real-time video to maintain higher resolution in peripheral regions is proposed. The idea is implemented with a fast algorithm for multi-foveation processing, in conjunction with standard-compliant decoding. The new multi-foveation algorithm is integrated with the H.264/AVC standard for testing. Simulation results show a compression gain ranging from 2.25% to more than 11%, without degrading the perceived quality and PSNR and with minimal addition to the complexity of a standard uniform-resolution codec.
POCS-based frame-theoretic approach for peak-to-average power ratio reduction in OFDM

A new method for reducing peak-to-average power ratio (PAPR) in OFDM is proposed. The new method is based on using a projection-onto-convex-sets (POCS) algorithm in conjunction with the erasure pattern selection (EPS) method, which uses frame expansion for adding redundancy to the data. Part of the redundancy is removed by examining several patterns for erasing channels and selecting for transmission the pattern that produces the lowest PAPR. The residual redundancy in the data is exploited at the receiver to aid both the reconstruction of the erased data and correction of errors. The implementation is aided with the incorporation of a projection-onto-convex-sets (POCS) method in EPS in order to select and assign the best values to the unused subchannels and further reduce the PAPR. Two alternative methods of incorporating POCS are investigated. Complexity analysis and simulation results show that the POCS-based EPS method outperforms existing probabilistic methods while requiring lower overall complexity.
Content-aware instantly decodable network coding over wireless networks

Consider a scenario of broadcasting a common content to a group of cooperating wireless nodes that are within proximity of each other. Nodes in this group may receive partial content from the source due to packet losses over wireless broadcast links. We further consider that packet losses are different for different nodes. The remaining missing content at each node can then be recovered, thanks to cooperation among the nodes. In this context, the minimum amount of time that can guarantee a complete acquisition of the common content at every node is referred to as the "completion time". It has been shown that instantly decodable network coding (IDNC) reduces the completion time as compared to no network coding in this scenario. Yet, for applications such as video streaming, not all packets have the same importance and not all users are interested in the same quality of content. This problem is even more interesting when additional, but realistic constraints, such as strict deadline, bandwidth, or limited energy are added in the problem formulation. We assert that direct application of IDNC in such a scenario yields poor performance in terms of content quality and completion time. In this paper, we propose a novel Content-Aware IDNC scheme that improves content quality and network coding opportunities jointly by taking into account importance of each packet towards the desired quality of service (QoS). Our proposed Content-Aware IDNC (i) maximizes the quality under the completion time constraint, and (ii) minimizes the completion time under the quality constraint. We demonstrate the benefits of Content-Aware IDNC through simulations.
Frame Expansion Based Peak to Average Power Ratio Reduction in MIMO OFDM Systems

The integration of Orthogonal Frequency Division Multiplexing (OFDM) into Multiple Input Multiple Output (MIMO) systems is regarded as a promising technology to provide high performance in fourth generation (4G) broadband wireless communication systems. However, the inherent drawback of large Peak-to-Average Power Ratio (PAPR) for OFDM carries over to MIMO systems. This paper examines the use of Erasure Pattern Selection (EPS) developed for Single Input Single Output (SISO) systems for the task of reducing PAPR in MIMO-OFDM systems. A MIMO-EPS scheme is proposed for minimizing the peak power value over all antennas, which is shown to produce a PAPR reduction gain around 1.5dB for 2 transmit antennas compared with the conventional MIMO-OFDM. The scheme is analyzed to show its significant performance advantages and lower computational complexity compared with an existing SeLective Mapping (SLM) scheme.
Multi-level IIR digital filters

A procedure for approximating a multiband response with piecewise-constant magnitude at arbitrary levels is described. The design is based on the use of a cascade of two-level IIR filters. Analytic results are presented for the design of two-level filters at levels p and q for obtaining equiripple or monotone response, similar to classical filter design. The location of the poles and zeros is derived. The general multiband design can be carried out using numerical procedures. The filter can be configured as a parallel connection of all-pass sections. A multiplicative complementary pair of causal, stable two-level filters using this structure is presented. Multilevel approximation using a cascade of these filters is described.
Multiple Description Coding over Erasure Channels

In this paper, we study the optimal rate allocation of multiple description coding over multiple erasure channels in order to attain the minimum average distortion of the recovered message at the receiver. The results of this investigation are subsequently used to determine conditions under which the optimal rate allocation is characterized by transmission of one description over a single channel, i.e. single description coding. We formulate the optimal rate allocation problem by using rate- distortion theory under the constraint that the total coding rate is fixed and solve the problem by using numerical methods. Furthermore, we derive a closed-form analytical solution to the optimal rate allocation problem under four conditions and verify that the analytical solution is consistent with the numerical results. Also, we present a heuristic that captures the solution to the optimal rate allocation problem and can be used to determine the number of descriptions and relative rates required to achieve optimality.
The design and application of optimal FIR fractional-slope phase filters

A new technique for the design of FIR fractional-slope phase filters based on Chebyshev approximation is described and analyzed. The technique results from a formulation of the problem which satisfies the Haar condition, thus allowing the use of the efficient Remez exchange algorithm. The new design is implemented with a modification of the McClellan-Parks-Rabiner FIR filter design program. The resulting fractional-slope phase filters are shown to have a complex error function that is essentially equiripple in magnitude. The new technique may be used for designing parallel elements of a multirate filter, such as the polyphase interpolation filter, or for stand-alone filters used as fractional-slope phase shifters. The advantages of the new technique are the simplicity and numerical stability of the design program and the lack of restrictions on phase slope specification.
Investigating chaos in ozone layer depletion at Pakistan air space

Phenomena like, atmospheric pollution, temperature variability, global warming, or ozone layer depletion (OLD) may be analyzed for forecasts etc. by solving the primitive dynamic equations along with the continuity and energy ones. The environmental variables actually observed are the consequences of thousand of events, some of which may be poorly defined or imperfectly understood. However, such atmospheric models of meteorological phenomena are simplistic in their nature, in the sense of largely hiding the character of nature as it ‘really’ is. This failure of reaching an exact solution and the fact that environmental phenomena nearly always include random components prompt us to leave the purely deterministic approach and invoke instead pseudo-randomness or randomness (stochasticity).
Gesture cues for conversational interaction in monocular video

We present our work on the determination of cues for discourse segmentation in free-form gesticulation accompanying speech in natural conversation. The basis for this integrating between gesticulation and speech discourse is the psycholinguistic concept of the co-equal generation of gesture and speech from the same semantic intent. We use the psycholinguistic device known as the 'catchment' as the locus around which this integration proceeds. We videotape gesture and speech elicitation experiments in which a subject describes her living space to an interlocutor. We extract the gestural motion of both hands using the Vector Coherence Mapping algorithm that combines spatial, momentum and skin color constraints in parallel using a fuzzy image processing approach. We extract the voiced units in the discourse as F/sub 0/ units are correlate these with transcribed speech. Psycholinguistics researchers perceptually micro-analyze the same video tape to produce a transcript that is annotated with the video timestamp and perceived gesture-speech entities. These serve to direct our high level analysis of the gesture trace and F/sub 0/ data. We report the results of our analysis that show that the feature of 'handedness' and the kind of symmetry in two-handed gestures provide effective cues for discourse segmentation. We also present observations on how the gesture traces provide cues to segment hand use, high level discourse repair and super-segmental cues for discourse grouping.
A procedure for antenna array pattern synthesis

In this paper, a new iterative method for any shaped pattern synthesis for one- and two-dimensional antenna arrays is described. The object is to meet prescribed constraints on the power pattern, with an assumption on the number of antenna array elements at specified locations. The synthesis problem is solved using the method of projection on convex sets, by modeling the constraints in terms of convex sets whose elements are vectors representing the excitation coefficients. Two underlying frameworks used in solving the problem are the l2Hilbert Space and an inner product space based on convolution. The synthesis procedure is implemented using a Fast Fourier Transform algorithm.
Robust data-hiding in audio

A novel high capacity data hiding technique for digital audio is proposed. Imperceptibility of the embedded data is ensured based on the masking property of the human auditory system (HAS). Audio signal is decomposed into subband signals, some of which are selected for embedding data using finite-length impulse response approximations to allpass digital filters. Data detection is based on finding the filter pole-zero locations, which is achieved by power spectrum estimation of the data embedded audio signal. Performance of the proposed scheme is evaluated for different data encoding strategies. The proposed method is robust to desynchronization attacks as well as other standard data manipulation attacks
Erasure pattern selection with active constellation extension for peak-to-average power ratio reduction in OFDM

A novel approach to the reduction of peak-to-average power ratio (PAPR) in orthogonal frequency-division multiplexing (OFDM) systems is presented here, which is a combination of erasure pattern selection (EPS) and generalized active constellation extension (ACE). The former introduces redundancy into the data of an OFDM system by using an overcomplete expansion, or frame. The redundancy serves the dual purpose of error correction and PAPR reduction. The latter predistorts the signal in a controlled way in order to reduce the symbols degradation due to clipping. Extensive simulations in additive white Gaussian noise (AWGN) channel show how this approach can improve the PAPR reduction without degrading the bit error rate (BER) performance.
Content-Based Rate-Adaptive transfer of SVC-encoded video over MIMO communication systems

A novel COntent-Based Rate-Adaptation (COBRA) model is proposed to improve the quality of video transmission over multiple-input multiple-output (MIMO) system with channel state information feedback (CSI). The model captures relationships among the video content type, video sub-stream bit-rates, achievable peak signal-to-noise ratios (PSNR), and channel bit error rate (BER). COBRA facilitates joint selection of physical layer parameters and video sub-stream configuration. Unlike existing methods, the COBRA model offers an efficient way of balancing losses in PSNR due to channel errors and non-transmission of some enhancements layers in a sub-stream, with a judicious mechanism of selecting sub-stream configurations and communication parameters. Simulations show that COBRA maintains video quality at acceptable levels over wide range of low channel signal-to-noise ratio (SNR) values. It achieves the same video PSNR as obtained by the complete stream transmission at 10 dB higher channel SNR.
Antenna selection and power control in MIMO systems with continuously varying channels

Existing limited feedback methods for Multiple- Input Multiple-Output (MIMO) systems focus largely on block fading conditions whereas, in practice, channels change continuously over time. In this paper, we investigate adaptive transmission over a continuously varying channel (CVC). A combination of Kalman channel tracking, truncated channel inversion (TCI) antenna selection, and power control, is used to achieve bit error rates that are lower than those obtained with existing schemes. Using Kalman filtering for pilot-based channel tracking as well as decision-directed channel tracking, our scheme achieves about 3.6 dB gain over the eigen-mode antenna selection scheme and 1.5 dB gain over the unitary precoding scheme, when operating at a BER of 10-5.
Parallel Nonuniform Discrete Fourier Transform (P-NDFT) Over a Random Wireless Sensor Network

Reduced execution time and increased power efficiency are important objectives in the distributed execution of collaborative signal processing tasks over wireless sensor networks (WSNs). Meanwhile, Fourier transforms are among the most widely used frequency analysis tools in WSNs for studying the behavior of sensed phenomena. Several energy-efficient in-network Fourier transform computation algorithms have been proposed for WSNs. Most of these works assume that the sensors are equally spaced over a one-dimensional (1D) region. However, in practice, the sensors are usually randomly distributed over a two-dimensional (2D) plane. Consequently, the conventional 2D Fast Fourier Transform (FFT) designed for data sampled on a uniform grid is not applicable in such environments. We address this problem by designing a distributed hybrid structure consisting of local Non-equispaced Discrete Fourier Transform (NDFT) and global FFT computations. First, the NDFT method is applied within suitably selected clusters to obtain the initial uniform Fourier coefficients within allowable estimation error bounds. We investigate both classical linear and generalized interpolation methods for computing the NDFT coefficients within each cluster. Second, a separable 2D FFT is applied over all clusters using our proposed energy-efficient 1D FFT computation method, which reduces communication costs by employing a novel binary representation mapping strategy for data exchanges between sensors. The proposed techniques are implemented on the SIDnet-SWANS platform, and the tradeoffs between communication cost, execution time, and energy consumption are studied.
Digital filter network sensitivity with multiple identical transmittances

In this paper we obtain results that are useful in the investigation of network sensitivity of a liner shift invariant discrete-time system to changes in the value of multiple identical transmittances. The expressions for the sensitivity generalize the results obtained in  and  for the case of network sensitivity with respect to single transmittances. The results can be applied in the study of systems where several parameters in different locations in the network are constrained to have identical values, or where several identical building blocks are used in the system realization.
Antenna Selection and Power Control for Limited Feedback MIMO Systems with Successive Interference Cancellation

Antenna selection has been shown to be effective in improving the bit error rate (BER) performance of multiple-input-multiple-output (MIMO) systems. Performance can be further improved by transmitting only when channel gains are sufficiently high and by using power control to compensate for channel variations. Truncated channel inversion is an adaptive power control scheme that compensates for fading above a certain cutoff fade depth: below the cutoff level the transmission is stopped. In this paper, we propose a novel antenna selection scheme that incorporates the truncated channel inversion power control to improve the BER performance of spatial multiplexing (SM) systems with linear receivers. For systems transmitting at high data rates, further improvements are obtained by incorporating successive interference cancellation (SIC). Simulations show that, in flat Rayleigh fading channels, the proposed antenna selection scheme significantly outperforms well-known existing schemes, providing a gain of 3.75 dB and 6.25 dB over two such schemes at a BER of 10-5
A Robust Method to Estimate Time Split in Second Heart Sound Using Instantaneous Frequency Analysis

Closure of the aortic valve (A2) and the pulmonary valve (P2) generates the second heart sound (S2). The time separation between A2 and P2 is known as the A2- P2 split and it has very important diagnostic potential. Methods proposed in the past to measure the split noninvasively are limited either by prior signal modeling assumptions or by reliance on manual processing in key steps. In this work, we propose a new method that is devised to noninvasively provide an automated measurement of the time split between A2 and P2 with minimal prior assumptions on signal models. Our method is based on tracking the changes of the instantaneous frequency (IF) of S2 via time frequency representation of the S2 obtained by smoothed Wigner-Ville Distribution. The cues provided by the changes in the IF trajectory are analyzed using an automated procedure to identify the onset of the P2 pulse. Simulations are carried out to demonstrate the effectiveness of the procedure in estimating the split. The performance of the method in the presence of noise varying between 6 dB and 8 dB for several trials and interference is investigated and the robustness of the method is demonstrated.
Elliptic filter design for a class of generalized halfband filters

In multirate processing, symmetric finite impulse response halfband filters constitute an important class of filters that are useful for sampling rate alteration by a factor of two. Generalizing the notion of halfband filters to include infinite impulse response filters, a class of generalized halfband filters is examined and its properties are studied. The filters are efficient and have low roundoff noise. A filter design program has been developed to design a special class of elliptic filters taking into account restrictions due to the generalized halfband characteristics. The procedure adapts the results of elliptic filter design  to this special case. It is shown that if the passband and stopband edge frequencies are related, then these filters are computationally efficient even when no sampling rate change is needed.
Peak-to-average power ratio reduction in OFDM: optimal and suboptimal combination of erasure pattern selection and probabilistic methods

A procedure for improving peak-to-average power ratio (PAPR) performance of probabilistic methods in OFDM is proposed. The procedure incorporates a method that introduces redundancy into the data via frame expansion. The mapping is followed by selecting the best pattern for erasing some samples before transmission. This erasure pattern selection (EPS) method can be effectively combined with existing probabilistic methods to produce a significant improvement in performance. Optimally combining the methods is computationally demanding. Suboptimal procedures proposed for complexity reduction in PTS are adapted for combining EPS with PTS. Four methods are proposed and compared through complexity analysis and simulations, and the trade-off in complexity and PAPR improvement is presented.