Warping Algorithm Research Articles

Segment location for single-phase-to-ground fault in neutral non-effectively grounded system based on distributed electric-field measurement

Based on the analysis of the electric-field information distributing along the transmission lines, this paper proposes a new segment location scheme for single-phase-to-ground fault (SPG) in the neutral non-effectively grounded system. Through theoretical derivation, an optimum measuring position can be found at which the electric-field component has the proportional relation with zero-sequence voltage on the corresponding mapping location of transmission line. Then it can actualize the non-contacted and distributed zero-sequence voltages measurement with the remarkable advantages of safety and convenience. In view of there being the transient changes of the electric field at the moment of failure, as well as there being great difference between the electric-field measured at the upstream and downstream segments adjacent to the grounded point, the transient electric-field waveforms of different measuring points along the lines are obtained and the similarity degrees of waveforms from each adjacent measuring points are quantified based on Dynamic Time Warping (DTW) algorithm. DTW algorithm can highlight and quantify the above-mentioned differences and weaken the requirement of synchronous measurement at multiple points. Several simulation cases are designed with different fault conditions and the analysis results are compared to verify the effectiveness and sensitivity of the proposed method.

A new higher-resolution multi-trace seismic discontinuity attribute based on a Dynamic Time Warping algorithm

Abstract A new machine-learning approach based on a Dynamic Time Warping (DTW) algorithm is introduced to detect faults and fractures in 3D seismic data from an unconventional resource play in Eastern Cis- Caucasia (Russia). This novel approach allows for better edge detection in seismic amplitude volumes because it employs a detailed comparison of two neighbouring traces to detect discontinuity via a minimal horizontal distance. For benchmarking purposes the proposed DTW method is compared to a widely used multi-trace attribute (Variance). Subsequently, both calculated attribute cubes serve as an input for ANT-Tracking to delineate fault strike and fracture corridor trends. A comparison of results shows that better resolution and more complete fault images are obtained when the DTW method is applied.

Development of Smart Healthcare System Based on Speech Recognition Using Support Vector Machine and Dynamic Time Warping

This paper presents an effective solution based on speech recognition to provide elderly people, patients and disabled people with an easy control system. The goal is to build a low-cost system based on speech recognition to easily access Internet of Things (IoT) devices installed in smart homes and hospitals without relying on a centralized supervisory system. The proposed system used a Raspberry Pi board to control home appliances through wireless with smartphones. The main purpose of this system is to facilitate interactions between the user and home appliances through IoT communications based on speech commands. The proposed framework contribution uses a hybrid Support Vector Machine (SVM) with a Dynamic Time Warping (DTW) algorithm to enhance the speech recognition process. The proposed solution is a machine learning-based system for controlling smart devices through speech commands with an accuracy of 97%. The results helped patients and elderly people to access and control IoT devices that are compatible with our system using speech recognition. The proposed speech recognition system is flexible with scalability and availability in adapting to existing smart IoT devices, and it provides privacy in managing patient devices. The research provides an effective method to integrate our systems among medical institutions to help elderly people and patients.

Identification of Urban Functional Regions in Chengdu Based on Taxi Trajectory Time Series Data

Overall scientific planning of urbanization layout is an important component of the new period of land spatial planning policies. Defining the main functions of different spaces and dividing urban functional areas are of great significance for optimizing the land development pattern. This article identifies and analyses urban functional areas from the perspective of data mining. The results of this method are consistent with the actual situation. In this paper, representative taxi trajectory data are selected as the research basis of urban functional areas. First, based on trajectory data from Didi Chuxing within the high-speed road surrounding Chengdu, we generated trajectory time sequence data and used the dynamic time warping (DTW) algorithm to generate a time series similarity matrix. Second, we utilized the K-medoid clustering algorithm to generate preliminary results of land clustering and selected the results with high classification accuracy as the training samples. Then, the k-nearest neighbour (KNN) classification algorithm based on DTW was performed to classify and identify the urban functional areas. Finally, with the help of point-of-interest (POI) auxiliary analysis, the final functional layout in Chengdu was obtained. The results show that the spatial structure of Chengdu is complex and that the urban functions are interlaced, but there are still rules that are followed. Moreover, traffic volume and inflow data can better reflect the travel rules of residents than simple taxi on–off data. The original DTW calculation method has high temporal complexity, which can be improved by normalization and the reduction of time series dimensionality. The semi-supervised learning classification method is also applicable to trajectory data, and it is best to select training samples from unsupervised learning. This method can provide a theoretical basis for urban land planning and has auxiliary and guiding value for urbanization layout in the context of land spatial planning policies in the new era.

Probability Model Based on Cluster Analysis to Classify Sequences of Observations for Small Training Sets

The problem of recognizing patterns, when there are few training data available, is particularly relevant and arises in cases when collection of training data is expensive or essentially impossible. The work proposes a new probability model MC&CL (Markov Chain and Clusters) based on a combination of markov chain and algorithm of clustering (self-organizing map of Kohonen, k-means method), to solve a problem of classifying sequences of observations, when the amount of training dataset is low. An original experimental comparison is made between the developed model (MC&CL) and a number of the other popular models to classify sequences: HMM (Hidden Markov Model), HCRF (Hidden Conditional Random Fields),LSTM (Long Short-Term Memory), kNN+DTW (k-Nearest Neighbors algorithm + Dynamic Time Warping algorithm). A comparison is made using synthetic random sequences, generated from the hidden markov model, with noise added to training specimens. The best accuracy of classifying the suggested model is shown, as compared to those under review, when the amount of training data is low.

SSDTW: Shape segment dynamic time warping

In order to increase the yield of a process, it is essential to establish a process control based on manufacturing data. Process management systems mainly consist of statistical process control (SPC), fault detection and classification (FDC), and advanced process control (APC), and are modeled using time series data. However, large amounts of time series data and various distributions are collected in the process; hence, preprocessing measures, such as length adjustment, are essential for modeling. Dynamic time warping (DTW) has been widely used as an algorithm that can measure the similarity between two different time series data and adjust their length. However, owing to the complex structure and time lag of processing time series data, there are limitations in applying the traditional DTW. Therefore, to solve this problem, we propose the shape segment dynamic time warping (SSDTW) algorithm that improves DTW in consideration of the structure information of time series data. By using the maximum overlap discrete wavelet transform (MODWT), the proposed method reflects the peripheral information of the time series data and divides the time series data interval to achieve a reasonable local alignment path. SSDTW attains more accurate alignment paths than DTW, derivative dynamic time warping (DDTW), and shapeDTW. Experiments conducted using semiconductor signal data and UCR time series data sets show that the proposed method is more effective than DTW, DDTW, and shapeDTW.

Fault Diagnosis of Industrial Gear Hobbing Machine

The aim of this paper is to develop a fault diagnosis algorithm by vibrational analysis for an industrial gear hobbing machine. Gear Hobbing is the most dominant and profitable process for manufacturing high quality gears. In order to sustain the market competition gear manufacturers, need to produce high quality gears with minimum possible cost. However, catastrophic failures do occur in gear hobbing process which causes unexpected machine down time and revenue loss. These failures can be avoided by using condition monitoring approaches. In the proposed approach vibration data during different faults such as lubrication error, excessive feed rate, loose bearing error is collected from an industrial gear hobbing machine using three axis MEMS accelerometer. The collected data is analyzed and classified with spectral kurtosis and Dynamic Time Warping algorithm. The efficiency of the proposed approach is 90 percent as determined by experimental results. The proposed approach can provide a low-cost solution for predictive maintenance for gear hobbing industries..

Downsizing Without Downgrading: Approximated Dynamic Time Warping on Nonvolatile Memories

In recent years, time-series data have emerged in a variety of application domains, such as wireless sensor networks and surveillance systems. To identify the similarity between time-series data, the Euclidean distance and its variations are common metrics that quantify the differences between time-series data. However, the Euclidean distance is limited by its inability to elastically shift with the time axis, which motivates the development of dynamic time warping (DTW) algorithms. While DTW algorithms have been proven very useful in diversified applications like speech recognition, their efficacy might be seriously affected by the resolution of the time-series data. However, high-resolution time-series data might take up a gigantic amount of main memory and storage space, which will slow down the DTW analysis procedure. This makes the upscaling of DTW analysis more challenging, especially for in-memory data analytics platforms with limited nonvolatile memory space. In this paper, we propose a strategy to downsample time-series data to significantly reduce their size without seriously affecting the precision of the results obtained by DTW algorithms (downsizing without downgrading). In other words, this paper proposes a technique to remove the unimportant details that are largely ignored by DTW algorithms. The efficacy of the proposed technique is verified by a series of experimental studies, where the results are quite encouraging.

Implementation of Lightweight eHealth Applications on a Low-Power Embedded Processor

The rapid development of Internet of Things (IoT) has opened new opportunities for healthcare systems through so-called eHealth systems. With the help of monitoring using portable IoT devices with biomedical sensors, disease diagnoses can be conducted in real time. However, there is a challenge in that monitoring is an always-on activity that requires constant power supply and IoT devices are battery-powered and face heavy resource constraints. This work addresses a realistic implementation of a low-power eHealth device using both hardware and software approaches. We realize various lightweight eHealth applications (particularly monitoring applications) using a memory-conscious dynamic time warping (DTW) algorithm to be deployed on a small and low-power embedded processor. Actual prototypes of the processor are currently being fabricated. Our evaluation showcases the effectiveness of our work compared with other state-of-the-art embedded processors in terms of circuit area (fabrication cost) and power efficiency. We also demonstrated the scalability of the software implementation by varying the amount of data used in DTW for various eHealth monitoring applications.

A Novel Detection and Recognition Method for Continuous Hand Gesture Using FMCW Radar

In this article, a novel method for continuous hand gesture detection and recognition is proposed based on a frequency modulated continuous wave (FMCW) radar. Firstly, we adopt the 2-Dimensional Fast Fourier Transform (2D-FFT) to estimate the range and Doppler parameters of the hand gesture raw data, and construct the range-time map (RTM) and Doppler-time map (DTM). Meanwhile, we apply the Multiple Signal Classification (MUSIC) algorithm to calculate the angle and construct the angle-time map (ATM). Secondly, a hand gesture detection method is proposed to segment the continuous hand gestures using a decision threshold. Thirdly, the central time-frequency trajectory of each hand gesture spectrogram is clustered using the k-means algorithm, and then the Fusion Dynamic Time Warping (FDTW) algorithm is presented to recognize the hand gestures. Finally, experiments show that the accuracy of the proposed hand gesture detection method can reach 96.17%. The hand gesture average recognition accuracy of the proposed FDTW algorithm is 95.83%, while its time complexity is reduced by more than 50%.

Introducing a novel procedure for peak alignment in one-dimensional 1H-NMR spectroscopy: a prerequisite for chemometric analyses of wine samples.

Shifted peak positions in 1H-nuclear magnetic resonance (1H-NMR) spectroscopy of wine samples are inevitably occurring mainly due to variations in the sample matrix, which consists of ethanol, glycerol, carbohydrates, acids, phenolic compounds, minerals, and aroma compounds. Slight variations in pH during sample preparation or fluctuations in instrumental factors may contribute to shifted peak positions that need to be corrected before subjecting the NMR data to chemometric techniques to ensure samples are compared on the correct chemical shift scale. In the current work, a novel procedure for correcting 1H-NMR spectroscopy peak positions was developed by mapping of the raw NMR spectra on a common chemical shift axis using a simple interpolation approach. The mapping allowed a substantial correction of peak positions and subsequently reduced the computational burden in further spectral processing. Fine-tuning of the peak alignments was carried out efficiently by interval-wisely applying the correlation optimized warping (COW) algorithm. Our preceding mapping approach enabled the use of substantially simpler alignment parameters of the COW algorithm, thereby accelerating the whole peak alignment process. The developed procedure may also be suitable for facilitating NMR analyses of other sample types, such as agricultural, clinical or pharmaceutical samples in targeted or untargeted analytical approaches.

A Dynamic-Time Distance Based on Wavelet Decomposition for Subcellular Localization Classification

The use of bioinformatics to predict protein subcellular localization is a significant method to study protein function. In the present study, a novel dynamic-time distance measurement based on wavelet packet decomposition (WPD) was proposed for protein subcellular localization prediction. The protein sequence was firstly converted into multiple numerical signals according to physical/chemical properties. Following signal decomposition into multiple subsignals by wavelet packet decomposition, a comprehensive dynamic-time distance was obtained by the dynamic time warping (DTW) algorithm. Finally, the expected classification can be produced based on the new distance measurement. By introducing DTW, the present algorithm can overcome the shortcoming that traditional methodologies can not measure the similarity of unequal-length sequences. Additional, multi frequency band subsignals can retain more information to achieve accurate results. It was suggested that our algorithm provides superior classification recognition by setting traditional methods as a comparative experiment in the E.coli dataset. It can distinguish cytoplasm and cell membrane proteins that are particularly difficult to be identified by the traditional methodologies.

Image-Based Rendering for Large-Scale Outdoor Scenes With Fusion of Monocular and Multi-View Stereo Depth

Image-based rendering (IBR) attempts to synthesize novel views using a set of observed images. Some IBR approaches (such as light fields) have yielded impressive high-quality results on small-scale scenes with dense photo capture. However, available wide-baseline IBR methods are still restricted by the low geometric accuracy and completeness of multi-view stereo (MVS) reconstruction on low-textured and non-Lambertian surfaces. The issues become more significant in large-scale outdoor scenes due to challenging scene content, e.g., buildings, trees, and sky. To address these problems, we present a novel IBR algorithm that consists of two key components. First, we propose a novel depth refinement method that combines MVS depth maps with monocular depth maps predicted via deep learning. A lookup table remap is proposed for converting the scale of the monocular depths to be consistent with the scale of the MVS depths. Then, the rescaled monocular depth is used as the constraint in the minimum spanning tree (MST)-based nonlocal filter to refine the per-view MVS depth. Second, we present an efficient shape-preserving warping algorithm that uses superpixels to generate the warped images and blend expected novel views of scenes. The proposed method has been evaluated on public MVS and view synthesis datasets, as well as newly captured large-scale outdoor datasets. In comparison with state-of-the-art methods, the experimental results demonstrated that the proposed method can obtain more complete and reliable depth maps for the challenging large-scale outdoor scenes, thereby resulting in more promising novel view synthesis.

Smartphone-Based Indoor Localization With Integrated Fingerprint Signal

Indoor localization of smartphones has received much attention recently and the smartphone localization is essential to a wide range of applications in office buildings, nursing homes, parking lots, and other public places. Existing solutions relying on inertial sensors or received signal strength suffer from large location errors and poor stability. We observe an opportunity in the recent trend of increasing numbers of wireless transmitters installed in indoor spaces to design a precise and robust indoor localization solution. We can extract fine-grained channel state information from wireless transmitters for indoor fingerprint localization. However, the accuracy of localization relying on a single physical quantity is limited and difficult to self-correct. This study proposes an integrated channel state information (CSI) and magnetic field strength (MFS) localization method (CSMS) that achieves sub-meter accuracy for smartphones. CSMS constructs an integrated fingerprint map of CSI and MFS and proposes the Local Dynamic Time Warping algorithm for geomagnetic tracking and the Multi-Module Data k-Nearest Neighbor algorithm for fusion fingerprint dynamic weighted comparison. By doing so, CSMS outputs enhanced accuracy with low cost, while overcoming the respective drawbacks of each individual sub-system. We conduct extensive experiments in two scenarios to validate the performance of CSMS. The results of experimental show that the mean distance error in both scenarios is less than 0.5m which is significantly superior to existing smartphone-based indoor positioning methods.

Evaluating global and local sequence alignment methods for comparing patient medical records

BackgroundSequence alignment is a way of arranging sequences (e.g., DNA, RNA, protein, natural language, financial data, or medical events) to identify the relatedness between two or more sequences and regions of similarity. For Electronic Health Records (EHR) data, sequence alignment helps to identify patients of similar disease trajectory for more relevant and precise prognosis, diagnosis and treatment of patients.MethodsWe tested two cutting-edge global sequence alignment methods, namely dynamic time warping (DTW) and Needleman-Wunsch algorithm (NWA), together with their local modifications, DTW for Local alignment (DTWL) and Smith-Waterman algorithm (SWA), for aligning patient medical records. We also used 4 sets of synthetic patient medical records generated from a large real-world EHR database as gold standard data, to objectively evaluate these sequence alignment algorithms.ResultsFor global sequence alignments, 47 out of 80 DTW alignments and 11 out of 80 NWA alignments had superior similarity scores than reference alignments while the rest 33 DTW alignments and 69 NWA alignments had the same similarity scores as reference alignments. Forty-six out of 80 DTW alignments had better similarity scores than NWA alignments with the rest 34 cases having the equal similarity scores from both algorithms. For local sequence alignments, 70 out of 80 DTWL alignments and 68 out of 80 SWA alignments had larger coverage and higher similarity scores than reference alignments while the rest DTWL alignments and SWA alignments received the same coverage and similarity scores as reference alignments. Six out of 80 DTWL alignments showed larger coverage and higher similarity scores than SWA alignments. Thirty DTWL alignments had the equal coverage but better similarity scores than SWA. DTWL and SWA received the equal coverage and similarity scores for the rest 44 cases.ConclusionsDTW, NWA, DTWL and SWA outperformed the reference alignments. DTW (or DTWL) seems to align better than NWA (or SWA) by inserting new daily events and identifying more similarities between patient medical records. The evaluation results could provide valuable information on the strengths and weakness of these sequence alignment methods for future development of sequence alignment methods and patient similarity-based studies.

Voice Based Retrieval using Convolution Neural Network in Deep Learning

In this paper, we propose a Content Based Voice Retrieval(CBVR) is used to search a specific audio files from a large data base. Using Deep learning features are learned automatically in the training phase. Convolution Neural Network is used in this research for CBVR. On this paper, we recommend a novel technique to key word search(KWS) in low-resource languages, which presents an replacement method for retrieving the phrases of curiosity, in particular for the out of vocabulary (OOV) ones. Our procedure contains the approaches of question-by using-illustration retrieval tasks into KWS and conducts the hunt by the use of the subsequence dynamic time warping (sDTW) algorithm. For this, text queries are modeled as sequences of function vectors and used as templates within the search. A Convolution neural network-headquartered model is informed to gain knowledge of a frame-degree distance metric to be used in sDTW and the right question model frame representations for this realized distance. This new procedure can be used as a substitute to traditional LVCSR-situated KWS programs, or in combination with them, to attain the intention of filling the gap between OOV and in-vocabulary (IV) retrieval performances.

Multiscale Community Detection in Functional Brain Networks Constructed Using Dynamic Time Warping.

Previous studies have focused on the detection of community structures of brain networks constructed with resting-state functional magnetic resonance imaging (fMRI) data. Pearson correlation is often used to describe the connections between nodes in the construction of functional brain networks, which typically ignores the inherent timing and validity of fMRI time series. To solve this problem, this study applied the Dynamic Time Warp (DTW) algorithm to determine the correlation between two brain regions by comparing the synchronization and asynchrony of the time series. In addition, to determine the best community structure for each subject, we further divided the brain network into different scales, and then detected the different communities in these brain networks by using Modularity, Variation of Information (VI) and Normalized Mutual Information (NMI) as structural monitoring variables. Finally, we affirmed each subject's best community structure based on them. The experiments showed that through the method proposed in this paper, we not only accurately discovered important components of seven basic functional subnetworks, but also found that the putamen and Heschl's gyrus have a relationship with the inferior parietal network. Most importantly, this method can also determine each subject's functional brain network density, thus confirming the findings of studies testing real brain networks.

Non-rigid alignment pipeline applied to human gait signals acquired with optical motion capture systems and inertial sensors

An accurate gait characterization is fundamental for diagnosis and treatment in both clinical and sportive fields. Although several devices allow such measurements, the performance comparison between the acquired signals may be a challenging task.A novel pipeline for the accurate non-rigid alignment of gait signals is proposed. In this paper, the measurements of Inertial Measurement Units (IMU) and Optical Motion Capture Systems (OMCAP) are aligned using a modified version of the Dynamic Time Warping (DTW) algorithm. The differences between the two acquisitions are evaluated using both global (RMSE, Correlation Coefficient (CC)) and local (Statistical Parametric Mapping (SPM)) metrics.The method is applied to a data-set obtained measuring the gait of ten healthy subjects walking on a treadmill at three different gait paces. Results show a global bias between the signal acquisition of 0.05°.Regarding the global metrics, a mean RMSE value of 2.65° (0.73°) and an average CC value of 0.99 (0.01) were obtained. The SPM profile shows, in each gait cycle phase, the percentage of cases when two curves are statistically identical and reaches an average of 48% (22%).

Choreographic Pattern Analysis from Heterogeneous Motion Capture Systems Using Dynamic Time Warping

The convention for the safeguarding of Intangible Cultural Heritage (ICH) by UNESCO highlights the equal importance of intangible elements of cultural heritage to tangible ones. One of the most important domains of ICH is folkloric dances. A dance choreography is a time-varying 3D process (4D modelling), which includes dynamic co-interactions among different actors, emotional and style attributes, and supplementary elements, such as music tempo and costumes. Presently, research focuses on the use of depth acquisition sensors, to handle kinesiology issues. The extraction of skeleton data, in real time, contains a significant amount of information (data and metadata), allowing for various choreography-based analytics. In this paper, a trajectory interpretation method for Greek folkloric dances is presented. We focus on matching trajectories’ patterns, existing in a choreographic database, to new ones originating from different sensor types such as VICON and Kinect II. Then, a Dynamic Time Warping (DTW) algorithm is proposed to find out similarities/dissimilarities among the choreographic trajectories. The goal is to evaluate the performance of the low-cost Kinect II sensor for dance choreography compared to the accurate but of high-cost VICON-based choreographies. Experimental results on real-life dances are carried out to show the effectiveness of the proposed DTW methodology and the ability of Kinect II to localize dances in 3D space.

Superimposing 3D Virtual Self + Expert Modeling for Motor Learning: Application to the Throw in American Football

We learn and/or relearn motor skills at all ages. Feedback plays a crucial role in this learning process, and Virtual Reality (VR) constitutes a unique tool to provide feedback and improve motor learning. In particular, VR grants the possibility to edit 3D movements and display augmented feedback in real time. Here we combined VR and motion capture to provide learners with a 3D feedback superimposing in real time the reference movements of an expert (expert feedback) to the movements of the learner (self-feedback). We assessed the effectiveness of this feedback for the learning of a throwing movement in American football. This feedback was used during (concurrent feedback) and/or after movement execution (delayed feedback), and it was compared with a feedback displaying only the reference movements of the expert. In contrast with more traditional studies relying on video feedback, we used the Dynamic Time Warping algorithm coupled to motion capture to measure the spatial characteristics of the movements. We also assessed the regularity with which the learner reproduced the reference movement along its path. For that, we used a new metric computing the dispersion of distance around the mean distance over time. Our results show that when the movements of the expert were superimposed on the movements of the learner during learning (i.e., self + expert), the reproduction of the reference movement improved significantly. On the hand, providing feedback about the movements of the expert only did not give rise to any significant improvement regarding movement reproduction.