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Optical Fiber Technology
journal homepage: www.elsevier.com/locate/yofte
Optical fiber intrusion signal recognition method based on TSVD-SCN
Zhiyong Sheng, Zhiqiang Zeng, Hongquan Qu
⁎
, Yuan Zhang
School of Information Science and Technology, North China University of Technology, Beijing 100144, China
ARTICLE INFO
Keywords:
Stochastic configuration networks
Truncated singular value decomposition
Optical fiber pre-warning system
Signal recognition
ABSTRACT
Stochastic Configuration Networks (SCN) introduce the inequality constraint of a supervised mechanism to
ensure the universal approximation property of learner model. However, in the processing of building SCN, due
to the properties of used activation function and the way of assigning the random input weights and biases of the
hidden nodes, the hidden output matrix is often ill-posed, i.e., the matrix can be of rank deficient or demonstrate
multicollinearity. Thus, the least squares method for evaluating the output weights may result in poor gen-
eralization performance for data modelling problems. This paper aims to overcome this drawback through
modifying the computation of the generalized pseudo inverse of the output matrix by a Truncated Singular Value
Decomposition (TSVD) method with an adaptively chosen truncation threshold. The improved SCN model is
then applied for recognizing intrusion signals in Optical Fiber Pre-warning System. Experimental results show
that the proposed improved algorithm can achieve higher recognition rate compared to the original SCN clas-
sifier.
1. Introduction
With the rapid development of optical fiber sensing technology, the
Optical Fiber Pre-warning System (OFPS) has aroused much attention
in various fields. The system is characterized by strong resistance to
electromagnetic interference and low construction difficulty, and often
applied for inspection of engineering structure safety, perimeter pro-
tection, and pre-warning for oil and gas pipeline safety [1,2]. When the
intrusion behavior appears, the major tasks of the OFPS are to timely
raise alarms and locate the intrusion signal accurately. A lot of re-
searches have been made by researchers on the fiber intrusion signal
detection. Some scholars had a further study in the distributed optical
fiber vibration sensor [3–5], and document [6] improved the Signal-to-
Noise Ratio (SNR) by using wavelet decomposition de-noising algo-
rithm of optical signals. Qu et al. proposed a Constant False Alarm Rate
(CFAR) algorithm with adaptive detection threshold under different
noise backgrounds [7,8], which greatly improved the performance of
OFPS detection algorithms. The above methods adopted the traditional
threshold setting method. However, the problem of false alarm is still
very serious due to the complex work environment of OFPS. Therefore,
it is significant to select a new recognition method to identify the fiber
signals with the background inference.
Over the past decades, neural network has been widely applied due
to its excellent learning and approximation ability to solve nonlinear
problems [9–12]. However, it is hard to find the right tradeoff between
model bias and model variance in building the networks. Practically,
the conventional learning models optimize the network using the error
Back-Propagation (BP) algorithm. Unfortunately, its local minima and
slow convergence will occur when the BP algorithm is performed. In
this case, one of the successful methods is the use of randomized models
[13–16]. Accordingly, the randomized learning techniques for neural
networks aroused the wide attention in the later 80s [17]. In the field of
machine learning, stochastic algorithms have great potential to reduce
computational complexity and were further developed in the early 90s
[18,19]. One of the classic models is the Random Vector Functional
Link (RVFL) proposed by [20]. The input weights and biases of RVFL
are selected randomly in accordance with the uniform distribution in a
given range. Besides, the linear regression method is employed to
transform the network which needs multiple iterative optimizations for
a linear least square problem. The above measures greatly reduce the
time required for training the networks. However, the range of random
parameters and the number of hidden layer nodes are directly related to
the performance of RVFL. Tyukin and Prokhorov proved that the ability
of RVFL networks to approximate the objective function is poor if the
above parameters are not properly selected [21]. Wang proposed the
Stochastic Configuration Network (SCN) with randomly selecting the
input weights and biases associated with inequality constraints and
adding the hidden nodes incrementally, which ensuring the universal
approximation property of the models [22–25]. The method of in-
troducing constraints to random algorithms greatly improves the
https://doi.org/10.1016/j.yofte.2019.01.023
Received 14 December 2018; Received in revised form 14 January 2019; Accepted 22 January 2019
Corresponding author.
E-mail address: qhqphd@ncut.edu.cn (H. Qu).
Optical Fiber Technology 48 (2019) 270–277
Available online 29 January 2019
1068-5200/ © 2019 Elsevier Inc. All rights reserved.
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