Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Classification of Signals01:30

Classification of Signals

889
In signal processing, signals are classified based on various characteristics: continuous-time versus discrete-time, periodic versus aperiodic, analog versus digital, and causal versus noncausal. Each category highlights distinct properties crucial for understanding and manipulating signals.
A continuous-time signal holds a value at every instant in time, representing information seamlessly. In contrast, a discrete-time signal holds values only at specific moments, often denoted as x(n), where...
889
Difference from Background: Limit of Detection01:05

Difference from Background: Limit of Detection

7.1K
The limit of detection (LOD) is the smallest amount of analyte that can be distinguished from the background noise. The LOD value corresponds to the concentration at which the analyte signal is three times larger than the standard deviation of the blank signal. Below this value, the analyte signal cannot be differentiated from the background noise. It is calculated by dividing the calibration slope by 3 times the standard deviation of the blank signals.
The LOD indicates the presence or absence...
7.1K
Classification of Systems-I01:26

Classification of Systems-I

301
Linearity is a system property characterized by a direct input-output relationship, combining homogeneity and additivity.
Homogeneity dictates that if an input x(t) is multiplied by a constant c, the output y(t) is multiplied by the same constant. Mathematically, this is expressed as:
301
Force Classification01:22

Force Classification

1.6K
Forces play a crucial role in the study of physics and engineering. They are essential in describing the motion, behavior, and equilibrium of objects in the physical world. Forces can be classified based on their origin, type, and direction of action.
Contact and non-contact forces are two of the most widely used categories of forces. As the name suggests, contact forces require physical contact between two objects to act upon each other. Examples of contact forces include frictional,...
1.6K
Classification of Systems-II01:31

Classification of Systems-II

241
Continuous-time systems have continuous input and output signals, with time measured continuously. These systems are generally defined by differential or algebraic equations. For instance, in an RC circuit, the relationship between input and output voltage is expressed through a differential equation derived from Ohm's law and the capacitor relation,
241
Comparison between RL and RC circuits01:24

Comparison between RL and RC circuits

4.3K
An RC circuit consists of resistance and capacitance, while in an RL circuit, capacitance is replaced by an inductor. RL and RC circuits are first-order differential circuits that store energy. An RC circuit stores energy in the electric field, while an RL circuit stores energy in the magnetic field. When connected to a battery, an RC circuit charges the capacitor, causing the current to decrease from maximum to zero upon being fully charged. This increases the voltage across the capacitor from...
4.3K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

High-Accuracy Lower-Limb Intent Recognition: A KPCA-ISSA-SVM Approach with sEMG-IMU Sensor Fusion.

Biomimetics (Basel, Switzerland)·2025
Same author

Experimental and simulation studies of strontium/fluoride-codoped hydroxyapatite nanoparticles with osteogenic and antibacterial activities.

Colloids and surfaces. B, Biointerfaces·2019
Same author

Crystalline Anionic Germanate Covalent Organic Framework for High CO<sub>2</sub> Selectivity and Fast Li Ion Conduction.

Chemistry (Weinheim an der Bergstrasse, Germany)·2019
Same author

Improved methane production and sulfate removal by anaerobic co-digestion corn stalk and levulinic acid wastewater pretreated by calcium hydroxide.

The Science of the total environment·2019
Same author

Prognostic value of TGF-β in lung cancer: systematic review and meta-analysis.

BMC cancer·2019
Same author

Proteomic characterization of bovine granulosa cells in dominant and subordinate follicles.

Hereditas·2019

Related Experiment Video

Updated: Sep 11, 2025

Author Spotlight: Investigating the Impact of Emotional Prosodies on Voice Recognition and Perception
05:48

Author Spotlight: Investigating the Impact of Emotional Prosodies on Voice Recognition and Perception

Published on: August 9, 2024

1.6K

A Contrastive Representation Learning Method for Event Classification in Φ-OTDR Systems.

Tong Zhang1, Xinjie Peng1, Yifan Liu1

  • 1School of Electrical and Mechanical Engineering, Pingdingshan University, Pingdingshan 467000, China.

Sensors (Basel, Switzerland)
|August 14, 2025
PubMed
Summary

A new method, CLWTNet, uses contrastive learning and wavelet transforms for classifying acoustic events in Φ-OTDR systems without needing labeled data. This approach enhances data efficiency and reduces labeling costs for distributed acoustic sensing.

Keywords:
contrastive representation learningevent classificationwavelet transform convolutionΦ-OTDR systems

More Related Videos

Interaction between Phonological and Semantic Processes in Visual Word Recognition using Electrophysiology
05:38

Interaction between Phonological and Semantic Processes in Visual Word Recognition using Electrophysiology

Published on: June 29, 2021

2.5K
Real-Time Monitoring of Neurocritical Patients with Diffuse Optical Spectroscopies
07:12

Real-Time Monitoring of Neurocritical Patients with Diffuse Optical Spectroscopies

Published on: November 19, 2020

2.2K

Related Experiment Videos

Last Updated: Sep 11, 2025

Author Spotlight: Investigating the Impact of Emotional Prosodies on Voice Recognition and Perception
05:48

Author Spotlight: Investigating the Impact of Emotional Prosodies on Voice Recognition and Perception

Published on: August 9, 2024

1.6K
Interaction between Phonological and Semantic Processes in Visual Word Recognition using Electrophysiology
05:38

Interaction between Phonological and Semantic Processes in Visual Word Recognition using Electrophysiology

Published on: June 29, 2021

2.5K
Real-Time Monitoring of Neurocritical Patients with Diffuse Optical Spectroscopies
07:12

Real-Time Monitoring of Neurocritical Patients with Diffuse Optical Spectroscopies

Published on: November 19, 2020

2.2K

Area of Science:

  • Fiber optic sensing
  • Signal processing
  • Machine learning

Background:

  • Phase-sensitive optical time-domain reflectometry (Φ-OTDR) is vital for distributed acoustic sensing.
  • Accurate event classification is essential for Φ-OTDR system deployment.
  • Existing methods require extensive labeled data, hindering practical application.

Purpose of the Study:

  • To introduce CLWTNet, a novel method for event classification in Φ-OTDR systems.
  • To address the bottleneck of labeled data dependency in current methods.
  • To develop a cost-effective and efficient solution for Φ-OTDR data analysis.

Main Methods:

  • CLWTNet utilizes contrastive representation learning on unlabeled Φ-OTDR data.
  • Time-domain signals are transformed into Short-Time Fourier Transform (STFT) images.
  • Wavelet transform convolution is integrated to capture complex signal features.

Main Results:

  • CLWTNet achieves competitive performance compared to supervised methods.
  • The proposed method outperforms existing unsupervised methods.
  • CLWTNet effectively extracts discriminative representations from unlabeled data.

Conclusions:

  • CLWTNet demonstrates the efficacy of unsupervised representation learning for Φ-OTDR event classification.
  • The method significantly reduces the need for costly data labeling.
  • CLWTNet offers a practical and efficient solution for real-world Φ-OTDR applications.