scholarly journals A METHOD OF TIME-SERIES CHANGE DETECTION USING FULL POLSAR IMAGES FROM DIFFERENT SENSORS

2018 ◽  
Vol XLII-3 ◽  
pp. 1127-1133
Author(s):  
W. Liu ◽  
J. Yang ◽  
J. Zhao ◽  
H. Shi ◽  
L. Yang
Keyword(s):  
Time Series ◽  
Change Detection ◽  
Time Series Data ◽  
Gaussian Mixture ◽  
Detection Methods ◽  
Series Data ◽  
Difference Image ◽  
Novel Method ◽  
Difference Images ◽  
The City

Most of the existing change detection methods using full polarimetric synthetic aperture radar (PolSAR) are limited to detecting change between two points in time. In this paper, a novel method was proposed to detect the change based on time-series data from different sensors. Firstly, the overall difference image of a time-series PolSAR was calculated by ominous statistic test. Secondly, difference images between any two images in different times ware acquired by R<sub>j</sub> statistic test. Generalized Gaussian mixture model (GGMM) was used to obtain time-series change detection maps in the last step for the proposed method. To verify the effectiveness of the proposed method, we carried out the experiment of change detection by using the time-series PolSAR images acquired by Radarsat-2 and Gaofen-3 over the city of Wuhan, in China. Results show that the proposed method can detect the time-series change from different sensors.

scholarly journals Jonckheere–Terpstra–Kendall-based non-parametric analysis of temporal differential gene expression

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Hitoshi Iuchi ◽  
Michiaki Hamada
Keyword(s):  
Gene Expression ◽  
Time Series ◽  
Time Course ◽  
Time Series Data ◽  
Expression Patterns ◽  
Detection Methods ◽  
Series Data ◽  
Expression Levels ◽  
Over Time ◽  
Non Parametric

Abstract Time-course experiments using parallel sequencers have the potential to uncover gradual changes in cells over time that cannot be observed in a two-point comparison. An essential step in time-series data analysis is the identification of temporal differentially expressed genes (TEGs) under two conditions (e.g. control versus case). Model-based approaches, which are typical TEG detection methods, often set one parameter (e.g. degree or degree of freedom) for one dataset. This approach risks modeling of linearly increasing genes with higher-order functions, or fitting of cyclic gene expression with linear functions, thereby leading to false positives/negatives. Here, we present a Jonckheere–Terpstra–Kendall (JTK)-based non-parametric algorithm for TEG detection. Benchmarks, using simulation data, show that the JTK-based approach outperforms existing methods, especially in long time-series experiments. Additionally, application of JTK in the analysis of time-series RNA-seq data from seven tissue types, across developmental stages in mouse and rat, suggested that the wave pattern contributes to the TEG identification of JTK, not the difference in expression levels. This result suggests that JTK is a suitable algorithm when focusing on expression patterns over time rather than expression levels, such as comparisons between different species. These results show that JTK is an excellent candidate for TEG detection.

scholarly journals ANALISIS PENGARUH INVESTASI SWASTA , PENGELUARAN PEMERINTAH, DAN PENDUDUK TERHADAP PERTUMBUHAN EKONOMI DI KOTA BITUNG

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yandiles Weya ◽  
Vecky A.J. Masinambow ◽  
Rosalina A.M. Koleangan
Keyword(s):  
Economic Growth ◽  
Time Series ◽  
Economic Activity ◽  
Time Series Data ◽  
Private Investment ◽  
Least Square ◽  
Series Data ◽  
Ordinary Least Square ◽  
North Sulawesi ◽  
The City

ANALISIS PENGARUH INVESTASI SWASTA , PENGELUARAN PEMERINTAH, DAN PENDUDUK TERHADAP PERTUMBUHAN EKONOMI DI KOTA BITUNG Yandiles Weya, Vecky A.J. Masinambow, Rosalina A.M. Koleangan. Fakultas Ekonomi dan Bisnis, Magister Ilmu EkonomiUniversitas Sam Ratulangi, Manado ABSTRAKPada suatu periode perekonomian mengalami pertumbuhan negatif berarti kegiatan ekonomi pada periode tersebut mengalami penurunan. Kota Bitung periode tahun 2004-2014 mengalami pertumbuhan ekonomi yang fluktuasi. Adanya fluktuasi ini dapat dipengaruhi oleh investasi swasta, belanja langsung, dan penduduk Pertumbuhan ekonomi merupakan salah satu tolok ukur keberhasilan pembangunan ekonomi di suatu daerah. Pertumbuhan ekonomi mencerminkan kegiatan ekonomi. Pertumbuhan ekonomi dapat bernilai positif dan dapat pula bernilai negatif. Jika pada suatu periode perekonomian mengalami pertumbuhan positif berarti kegiatan ekonomi pada periode tersebut mengalami peningkatan. Sedangkan jikaTahun 2004-2014 yang bersumber dari Badan Pusat Statistik Provinsi Sulut dan Kota Bitung. Metode analisis yang digunakan adalah model ekonometrik regresi berganda double-log (log-log) dengan metode Ordinary Least Square (OLS). Penelitian ini bertujuan untuk mengetahui apakah perkembangan investasi swasta, belanja langsung, dan penduduk berpengaruh terhadap pertumbuhan ekonomi Kota Bitung. Data yang dipakai menggunakan data time series periodeHasil regresi model pertumbuhan ekonomi dengan persamaan regresinya yaitu  LPDRB  =  - 4,445    +  0.036 LINV  +  0.049 LBL  +  2,229 LPOP.  Dari hasil tersebutmenunjukkan perkembangan investasi swasta, belanja langsung dan penduduk berpengaruh positif dan signifikan terhadap pertumbuhan ekonomi Kota Bitung.Kata Kunci :pertumbuhan ekonomi, belanja langsung, penduduk, regresi bergandaABSTRACT    The economy experienced a period of negative growth means economic activity in this period has decreased. Bitung-year period 2004-2014 economic growth fluctuations. These fluctuations can be influenced by private investment, direct spending, and population Economic growth is one measure of the success of economic development in an area. Economic growth reflects economic activity. Economic growth can be positive and can also be negative. If the economy experienced a period of positive growth means economic activity during the period has increased. Whereas if  years 2004-2014 are sourced from the Central Statistics Agency of North Sulawesi Province and Bitung. The analytical method used is an econometric model double-log regression (log-log) with Ordinary Least Square (OLS). This study aims to determine whether the development of private investment, direct spending, and population affect the economic growth of the city of Bitung. The data used using time series data period.    The results of the regression model of economic growth with the regression equation is LPDRB = - LINV 4.445 + 0.036 + 0.049 + 2.229 LPOP LBL. From these results show the development of private investment, direct expenditure and population positive and significant impact on economic growth of Bitung.Keywords: Economic growth, direct spending, population, regression.

scholarly journals Transient dynamic phenotypes as criteria for model discrimination: fold-change detection in Rhodobacter sphaeroides chemotaxis

2013 ◽  
Vol 10 (80) ◽  
pp. 20120935 ◽  
Author(s):  
Abdullah Hamadeh ◽  
Brian Ingalls ◽  
Eduardo Sontag
Keyword(s):  
Time Series ◽  
Change Detection ◽  
Rhodobacter Sphaeroides ◽  
Time Series Data ◽  
Series Data ◽  
Transient Dynamic ◽  
Experimental Time ◽  
Theoretical Assumptions ◽  
Experimental Time Series ◽  
Fold Change Detection

The chemotaxis pathway of the bacterium Rhodobacter sphaeroides shares many similarities with that of Escherichia coli . It exhibits robust adaptation and has several homologues of the latter's chemotaxis proteins. Recent theoretical results have correctly predicted that the E. coli output behaviour is unchanged under scaling of its ligand input signal; this property is known as fold-change detection (FCD). In the light of recent experimental results suggesting that R. sphaeroides may also show FCD, we present theoretical assumptions on the R. sphaeroides chemosensory dynamics that can be shown to yield FCD behaviour. Furthermore, it is shown that these assumptions make FCD a property of this system that is robust to structural and parametric variations in the chemotaxis pathway, in agreement with experimental results. We construct and examine models of the full chemotaxis pathway that satisfy these assumptions and reproduce experimental time-series data from earlier studies. We then propose experiments in which models satisfying our theoretical assumptions predict robust FCD behaviour where earlier models do not. In this way, we illustrate how transient dynamic phenotypes such as FCD can be used for the purposes of discriminating between models that reproduce the same experimental time-series data.

scholarly journals Periodicity Detection Method for Small-Sample Time Series Datasets

2010 ◽  
Vol 4 ◽  
pp. BBI.S5983 ◽  
Author(s):  
Daisuke Tominaga
Keyword(s):  
Time Series ◽  
Time Series Data ◽  
Small Sample ◽  
Detection Methods ◽  
Series Data ◽  
Computational Time ◽  
Signal Pathways ◽  
Periodicity Detection ◽  
Sampling Points ◽  
Sample Time

Time series of gene expression often exhibit periodic behavior under the influence of multiple signal pathways, and are represented by a model that incorporates multiple harmonics and noise. Most of these data, which are observed using DNA microarrays, consist of few sampling points in time, but most periodicity detection methods require a relatively large number of sampling points. We have previously developed a detection algorithm based on the discrete Fourier transform and Akaike's information criterion. Here we demonstrate the performance of the algorithm for small-sample time series data through a comparison with conventional and newly proposed periodicity detection methods based on a statistical analysis of the power of harmonics. We show that this method has higher sensitivity for data consisting of multiple harmonics, and is more robust against noise than other methods. Although “combinatorial explosion” occurs for large datasets, the computational time is not a problem for small-sample datasets. The MATLAB/GNU Octave script of the algorithm is available on the author's web site: http://www.cbrc.jp/%7Etominaga/piccolo/ .

scholarly journals Time series data interpretation for ‘wheel-flat’ identification including uncertainties

2019 ◽  
pp. 147592171988711
Author(s):  
Wen-Jun Cao ◽  
Shanli Zhang ◽  
Numa J Bertola ◽  
I F C Smith ◽  
C G Koh
Keyword(s):  
Time Series ◽  
Time Series Data ◽  
Model Updating ◽  
Information Gain ◽  
Data Interpretation ◽  
Detection Methods ◽  
Series Data ◽  
Point Selection ◽  
Modelling Uncertainties ◽  
Wheel Flat

Train wheel flats are formed when wheels slip on rails. Crucial for passenger comfort and the safe operation of train systems, early detection and quantification of wheel-flat severity without interrupting railway operations is a desirable and challenging goal. Our method involves identifying the wheel-flat size by using a model updating strategy based on dynamic measurements. Although measurement and modelling uncertainties influence the identification results, they are rarely taken into account in most wheel-flat detection methods. Another challenge is the interpretation of time series data from multiple sensors. In this article, the size of the wheel flat is identified using a model-falsification approach that explicitly includes uncertainties in both measurement and modelling. A two-step important point selection method is proposed to interpret high-dimensional time series in the context of inverse identification. Perceptually important points, which are consistent with the human visual identification process, are extracted and further selected using joint entropy as an information gain metric. The proposed model-based methodology is applied to a field train track test in Singapore. The results show that the wheel-flat size identified using the proposed methodology is within the range of true observations. In addition, it is also shown that the inclusion of measurement and modelling uncertainties is essential to accurately evaluate the wheel-flat size because identification without uncertainties may lead to an underestimation of the wheel-flat size.

Trend analysis of time-series data: A novel method for untargeted metabolite discovery

2010 ◽  
Vol 663 (1) ◽  
pp. 98-104 ◽  
Author(s):  
Sonja Peters ◽  
Hans-Gerd Janssen ◽  
Gabriel Vivó-Truyols
Keyword(s):  
Time Series ◽  
Trend Analysis ◽  
Time Series Data ◽  
Series Data ◽  
Novel Method ◽  
Analysis Of Time Series

scholarly journals Explainable Fraud Detection for Few Labeled Time Series Data

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Zhiwen Xiao ◽  
Jianbin Jiao
Keyword(s):  
Time Series ◽  
Time Series Data ◽  
Research Work ◽  
Fraud Detection ◽  
Predictive Performance ◽  
Multiple Instance Learning ◽  
Detection Methods ◽  
Series Data ◽  
Causal Explanations ◽  
Detection Technology

Fraud detection technology is an important method to ensure financial security. It is necessary to develop explainable fraud detection methods to express significant causality for participants in the transaction. The main contribution of our work is to propose an explainable classification method in the framework of multiple instance learning (MIL), which incorporates the AP clustering method in the self-training LSTM model to obtain a clear explanation. Based on a real-world dataset and a simulated dataset, we conducted two comparative studies to evaluate the effectiveness of the proposed method. Experimental results show that our proposed method achieves the similar predictive performance as the state-of-art method, while our method can generate clear causal explanations for a few labeled time series data. The significance of the research work is that financial institutions can use this method to efficiently identify fraudulent behaviors and easily give reasons for rejecting transactions so as to reduce fraud losses and management costs.

scholarly journals Towards Accurate Run-Time Hardware-Assisted Stealthy Malware Detection: A Lightweight, Yet Effective Time Series CNN-Based Approach

Cryptography ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 28
Author(s):  
Hossein Sayadi ◽  
Yifeng Gao ◽  
Hosein Mohammadi Makrani ◽  
Jessica Lin ◽  
Paulo Cesar Costa ◽  
...  
Keyword(s):  
Machine Learning ◽  
Time Series ◽  
Time Series Data ◽  
State Of The Art ◽  
Malware Detection ◽  
Detection Performance ◽  
Malicious Code ◽  
Detection Methods ◽  
Series Data ◽  
Run Time

According to recent security analysis reports, malicious software (a.k.a. malware) is rising at an alarming rate in numbers, complexity, and harmful purposes to compromise the security of modern computer systems. Recently, malware detection based on low-level hardware features (e.g., Hardware Performance Counters (HPCs) information) has emerged as an effective alternative solution to address the complexity and performance overheads of traditional software-based detection methods. Hardware-assisted Malware Detection (HMD) techniques depend on standard Machine Learning (ML) classifiers to detect signatures of malicious applications by monitoring built-in HPC registers during execution at run-time. Prior HMD methods though effective have limited their study on detecting malicious applications that are spawned as a separate thread during application execution, hence detecting stealthy malware patterns at run-time remains a critical challenge. Stealthy malware refers to harmful cyber attacks in which malicious code is hidden within benign applications and remains undetected by traditional malware detection approaches. In this paper, we first present a comprehensive review of recent advances in hardware-assisted malware detection studies that have used standard ML techniques to detect the malware signatures. Next, to address the challenge of stealthy malware detection at the processor’s hardware level, we propose StealthMiner, a novel specialized time series machine learning-based approach to accurately detect stealthy malware trace at run-time using branch instructions, the most prominent HPC feature. StealthMiner is based on a lightweight time series Fully Convolutional Neural Network (FCN) model that automatically identifies potentially contaminated samples in HPC-based time series data and utilizes them to accurately recognize the trace of stealthy malware. Our analysis demonstrates that using state-of-the-art ML-based malware detection methods is not effective in detecting stealthy malware samples since the captured HPC data not only represents malware but also carries benign applications’ microarchitectural data. The experimental results demonstrate that with the aid of our novel intelligent approach, stealthy malware can be detected at run-time with 94% detection performance on average with only one HPC feature, outperforming the detection performance of state-of-the-art HMD and general time series classification methods by up to 42% and 36%, respectively.

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