Sensors, Vol. 19, Pages 4091: Lychee Fruit Detection Based on Monocular Machine Vision in Orchard Environment
ng Shaoming Luo Due to the change of illumination environment and overlapping conditions caused by the neighboring fruits and other background objects, the simple application of the traditional machine vision method limits the detection accuracy of lychee fruits in natural orchard environments. Therefore, this research presented a detection method based on monocular machine vision to detect lychee fruits growing in overlapped conditions. Specifically, a combination of contrast limited adaptive histogram equalization (CLAHE), red/blue chromatic mapping, Otsu thresholding and morphology operations were adopted to segme...
Source: Sensors - September 21, 2019 Category: Biotechnology Authors: Qiwei Guo Yayong Chen Yu Tang Jiajun Zhuang Yong He Chaojun Hou Xuan Chu Zhenyu Zhong Shaoming Luo Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4092: Multi-View Fusion-Based 3D Object Detection for Robot Indoor Scene Perception
ianto Tandianus To autonomously move and operate objects in cluttered indoor environments, a service robot requires the ability of 3D scene perception. Though 3D object detection can provide an object-level environmental description to fill this gap, a robot always encounters incomplete object observation, recurring detections of the same object, error in detection, or intersection between objects when conducting detection continuously in a cluttered room. To solve these problems, we propose a two-stage 3D object detection algorithm which is to fuse multiple views of 3D object point clouds in the first stage and to eli...
Source: Sensors - September 21, 2019 Category: Biotechnology Authors: Li Wang Ruifeng Li Jingwen Sun Xingxing Liu Lijun Zhao Hock Soon Seah Chee Kwang Quah Budianto Tandianus Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4067: Autonomous Unmanned Aerial Vehicles in Search and Rescue Missions Using Real-Time Cooperative Model Predictive Control
Barreto Haddad Unmanned Aerial Vehicles (UAVs) have recently been used in a wide variety of applications due to their versatility, reduced cost, rapid deployment, among other advantages. Search and Rescue (SAR) is one of the most prominent areas for the employment of UAVs in place of a manned mission, especially because of its limitations on the costs, human resources, and mental and perception of the human operators. In this work, a real-time path-planning solution using multiple cooperative UAVs for SAR missions is proposed. The technique of Particle Swarm Optimization is used to solve a Model Predictive Control (MP...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Fabio A. A. Andrade Anthony Hovenburg Luciano Netto de de Lima Christopher Dahlin Rodin Tor Arne Johansen Rune Storvold Carlos A. M. Correia Diego Barreto Haddad Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4069: Fault Diagnosis of Rotary Parts of a Heavy-Duty Horizontal Lathe Based on Wavelet Packet Transform and Support Vector Machine
henyu Han The spindle box is responsible for power transmission, supporting the rotating parts and ensuring the rotary accuracy of the workpiece in the heavy-duty machine tool. Its assembly quality is crucial to ensure the reliable power supply and stable operation of the machine tool in the process of large load and cutting force. Therefore, accurate diagnosis of assembly faults is of great significance for improving assembly efficiency and ensuring outgoing quality. In this paper, the common fault types and characteristics of the spindle box of heavy horizontal lathe are analyzed first, and original vibration signals...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Hongyu Jin Avitus Titus Yulong Liu Yang Wang and Zhenyu Han Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4070: Applying OGC Sensor Web Enablement Standards to Develop a TDR Multi-Functional Measurement Model
Jian Time-domain reflectometry (TDR) is considered as a passive monitoring technique which reveals multi-functions, such as water level, bridge scour, landslide, and suspended sediment concentration (SSC), based on a single TDR device via multiplexing and related algorithms. The current platform for revealing TDR analysis and interpreted observations, however, is complex to access, thus a coherent data model and format for TDR heterogeneous data exchange is useful and necessary. To enhance the interoperability of TDR information, this research aims at standardizing the TDR data based on the Open Geospatial Consorti...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Chung Huang Guan Jian Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4071: Online Feature Selection for Robust Classification of the Microbiological Quality of Traditional Vanilla Cream by Means of Multispectral Imaging
os Z. Panagou The performance of an Unsupervised Online feature Selection (UOS) algorithm was investigated for the selection of training features of multispectral images acquired from a dairy product (vanilla cream) stored under isothermal conditions. The selected features were further used as input in a support vector machine (SVM) model with linear kernel for the determination of the microbiological quality of vanilla cream. Model training (n = 65) was based on two batches of cream samples provided directly by the manufacturer and stored at different isothermal conditions (4, 8, 12, and 15 °C), whereas mo...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Alexandra Lianou Arianna Mencattini Alexandro Catini Corrado Di Natale George-John E. Nychas Eugenio Martinelli Efstathios Z. Panagou Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4068: Comparative Study of Coupling Techniques in Lamb Wave Testing of Metallic and Cementitious Plates
es Gallardo Jordi Payá Lamb waves have emerged as a valuable tool to examine long plate-like structures in a faster way compared to conventional bulk wave techniques, which make them attractive in non-destructive testing. However, they present a multimodal and dispersive nature, which hinders signal identification. Oblique incidence is one of the most known methods to generate and receive Lamb waves and it is applied in different experimental arrangements with different types of sensors. In this work, several setups were conducted and compared to determine the optimal ones to launch and detect ultrasonic Lamb ...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Santiago V ázquez Jorge Gos álbez Ignacio Bosch Alicia Carri ón Carles Gallardo Jordi Pay á Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4073: Thickness Dependence of Ferroelectric and Optical Properties in Pb(Zr0.53Ti0.47)O3 Thin Films
Mu Hou Chou As a promising functional material, ferroelectric Pb(ZrxTi1−x)O3 (PZT) are widely used in many optical and electronic devices. Remarkably, as the film thickness decreases, the materials’ properties deviate gradually from those of solid materials. In this work, multilayered PZT thin films with different thicknesses are fabricated by Sol-Gel technique. The thickness effect on its microstructure, ferroelectric, and optical properties has been studied. It is found that the surface quality and the crystalline structure vary with the film thickness. Moreover, the increasing film...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: He Li Chen Qian Geng Bi Mu Hou Chou Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4072: Opportunistic Multipath Routing in Long-Hop Wireless Sensor Networks
-Il Kim To improve the packet delivery ratio in wireless sensor networks, many approaches such as multipath, opportunistic, and learning-based routing protocols have been proposed. However, the performance of the existing protocols are degraded under long-hop wireless sensor networks because the additional overhead is proportional to the number of hops. To deal with the overhead, we propose an opportunistic multipath routing that forecasts the required number of paths, as well as bifurcation based on opportunistic routing according to the reliability requirement. In the proposed scheme, an intermediate node is able to ...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Sangdae Kim Beom-Su Kim Kyong Hoon Kim Ki-Il Kim Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4074: Ultrasonic Power and Data Transfer through Multiple Curved Layers Applied to Pipe Instrumentation
Domingues Ultrasonic power and data transfer through multilayered curved walls was investigated using numerical and experimental analysis. The acoustic channel used in this paper was formed by two concentric pipes filled with water, aiming for applications that involve powering and monitoring sensors installed behind the pipe walls. The analysis was carried out in the frequency and time domains using numerical and experimental models. Power and data were effectively simultaneously transferred through the channel. A remote temperature and pressure sensor was powered and interrogated throughout all the layers, and the...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Takahashi Kubrusly Braga Quintero Figueiredo Domingues Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4075: Wearable Inertial Sensors to Assess Standing Balance: A Systematic Review
Agostini Wearable sensors are de facto revolutionizing the assessment of standing balance. The aim of this work is to review the state-of-the-art literature that adopts this new posturographic paradigm, i.e., to analyse human postural sway through inertial sensors directly worn on the subject body. After a systematic search on PubMed and Scopus databases, two raters evaluated the quality of 73 full-text articles, selecting 47 high-quality contributions. A good inter-rater reliability was obtained (Cohen’s kappa = 0.79). This selection of papers was used to summarize the available knowledge on the types ...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Ghislieri Gastaldi Pastorelli Tadano Agostini Tags: Review Source Type: research

Sensors, Vol. 19, Pages 4076: Super-Resolution Reconstruction of Cell Pseudo-Color Image Based on Raman Technology
Wu Bei Li Raman spectroscopy visualization is a challenging task due to the interference of complex background noise and the number of selected measurement points. In this paper, a super-resolution image reconstruction algorithm for Raman spectroscopy is studied to convert raw Raman data into pseudo-color super-resolution imaging. Firstly, the Raman spectrum data of a single measurement point is measured multiple times to calculate the mean value to remove the random background noise, and innovatively introduce the Retinex algorithm and the median filtering algorithm which improve the signal-to-noise ratio. The novel...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Yifan Yang Ming Zhu Yuqing Wang Hang Yang Yanfeng Wu Bei Li Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4077: On-Orbit Signal-to-Noise Ratio Test Method for Night-Light Camera in Luojia 1-01 Satellite Based on Time-Sequence Imagery
ng Su Night-light remote sensing imaging technologies have increasingly attracted attention with the development and application of focal plane arrays. On-orbit signal-to-noise ratio (SNR) test is an important link to evaluate night-light camera’s radiometric performance and the premise for quantitative application of remote sensing imageries. Under night-light illumination conditions, the illuminance of ground objects is very low and varies dramatically, the spatial uniformity of each pixel’s output cannot be guaranteed, and thus the traditional on-orbit test methods represented by variance...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Wei Wang Xing Zhong Zhiqiang Su Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4078: 3D Printing of BaTiO3 Piezoelectric Ceramics for a Focused Ultrasonic Array
ng-Hua Wu BaTiO3 (BTO) ceramics were fabricated based on stereolithography technology. The microstructures and electric properties of the BTO ceramics were studied. X-ray patterns of sintered BTO ceramics indicated that the tetragonal phase had formed, and the grain size increased clearly as BTO weight percentage increased. Moreover, the BTO ceramics exhibited good electric properties, with a piezoelectric constant d33 of 166 pC/N at 80% BTO weight percentage. To evaluate the properties of 3D printed BTO ceramics, a 1.4 MHz focused ultrasonic array was fabricated and characterized. The −6dB bandwidth of t...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Jian Cheng Yan Chen Jun-Wei Wu Xuan-Rong Ji Shang-Hua Wu Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4079: Wearable-Based Affect Recognition —A Review
Sensors, Vol. 19, Pages 4079: Wearable-Based Affect Recognition—A Review Sensors doi: 10.3390/s19194079 Authors: Philip Schmidt Attila Reiss Robert Dürichen Kristof Van Laerhoven Affect recognition is an interdisciplinary research field bringing together researchers from natural and social sciences. Affect recognition research aims to detect the affective state of a person based on observables, with the goal to, for example, provide reasoning for the person’s decision making or to support mental wellbeing (e.g., stress monitoring). Recently, beside of approaches based on audio, visual...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Philip Schmidt Attila Reiss Robert D ürichen Kristof Van Laerhoven Tags: Review Source Type: research

Sensors, Vol. 19, Pages 4057: Dissolved Gas Analysis Equipment for Online Monitoring of Transformer Oil: A Review
This study presents a review of the main DGA monitors, single- or multi-gas, their most important specifications, accuracy, repeatability and measurement range, the types of installation, valve or closed loop, and number of analogue inputs and outputs. This review shows the differences between the main existing DGA monitors and aims to help in the selection of the most suitable DGA monitoring approach according to the needs of each case. (Source: Sensors)
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Sergio Bustamante Mario Manana Alberto Arroyo Pablo Castro Alberto Laso Raquel Martinez Tags: Review Source Type: research

Sensors, Vol. 19, Pages 4059: Estimating Chlorophyll Content of Leafy Green Vegetables from Adaxial and Abaxial Reflectance
Lu As a primary pigment of leafy green vegetables, chlorophyll plays a major role in indicating vegetable growth status. The application of hyperspectral remote sensing reflectance offers a quick and nondestructive method to estimate the chlorophyll content of vegetables. Reflectance of adaxial and abaxial leaf surfaces from three common leafy green vegetables: Pakchoi var. Shanghai Qing (Brassica chinensis L. var. Shanghai Qing), Chinese white cabbage (Brassica campestris L. ssp. Chinensis Makino var. communis Tsen et Lee), and Romaine lettuce (Lactuca sativa var longifoliaf. Lam) were measured to estimate the lea...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Lu Bu Lu Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4060: An Event-Aware Cluster-Head Rotation Algorithm for Extending Lifetime of Wireless Sensor Network with Smart Nodes
ek Smart sensor nodes can process data collected from sensors, make decisions, and recognize relevant events based on the sensed information before sharing it with other nodes. In wireless sensor networks, the smart sensor nodes are usually grouped in clusters for effective cooperation. One sensor node in each cluster must act as a cluster head. The cluster head depletes its energy resources faster than the other nodes. Thus, the cluster-head role must be periodically reassigned (rotated) to different sensor nodes to achieve a long lifetime of wireless sensor network. This paper introduces a method for extending the li...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Marcin Lewandowski Bart łomiej Płaczek Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4058: Human Activities and Postures Recognition: From Inertial Measurements to Quaternion-Based Approaches
llerme This paper presents two approaches to assess the effect of the number of inertial sensors and their location placements on recognition of human postures and activities. Inertial and Magnetic Measurement Units (IMMUs)—which consist of a triad of three-axis accelerometer, three-axis gyroscope, and three-axis magnetometer sensors—are used in this work. Five IMMUs are initially used and attached to different body segments. Placements of up to three IMMUs are then considered: back, left foot, and left thigh. The subspace k-nearest neighbors (KNN) classifier is used to achieve the supervise...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Zmitri Fourati Vuillerme Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4063: Temperature Sensor Based on Side-Polished Fiber SPR Device Coated with Polymer
Yiping Wang A highly sensitive temperature sensor based on surface plasmon resonance (SPR) of a side-polished single mode fiber is demonstrated. The sensor consists of a gold film coated side-polished fiber covered by a layer of UV-curable adhesive. Before introducing the UV-curable adhesive, the gold-coated fiber exhibits refractive index (RI) sensitivity of 1691.6 nm/RIU to 8800 nm/RIU in the range of 1.32 to 1.43. The resonant wavelength of the SPR sensor shifts to 650 nm when the adhesive is coated on the gold film, and is fixed at about 725 nm when the adhesive is cured. Due to the high thermo-optic and thermal ex...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Shuhui Liu Shaoqing Cao Zhe Zhang Ying Wang Changrui Liao Yiping Wang Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4062: Boosting Multi-Vehicle Tracking with a Joint Object Detection and Viewpoint Estimation Sensor
We present a thorough experimental evaluation of our approaches with the GRAM-RTM, which will be useful for establishing further comparisons. The results obtained confirm that the simultaneous integration of vehicle localizations and pose estimations as observations in an EKF, improves the tracking results. (Source: Sensors)
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Roberto J. L ópez-Sastre Carlos Herranz-Perdiguero Ricardo Guerrero-G ómez-Olmedo Daniel O ñoro-Rubio Saturnino Maldonado-Basc ón Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4061: GNSS/LiDAR-Based Navigation of an Aerial Robot in Sparse Forests
Pereira Autonomous navigation of unmanned vehicles in forests is a challenging task. In such environments, due to the canopies of the trees, information from Global Navigation Satellite Systems (GNSS) can be degraded or even unavailable. Also, because of the large number of obstacles, a previous detailed map of the environment is not practical. In this paper, we solve the complete navigation problem of an aerial robot in a sparse forest, where there is enough space for the flight and the GNSS signals can be sporadically detected. For localization, we propose a state estimator that merges information from GNSS, Attitude...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Antonio C. B. Chiella Henrique N. Machado Bruno O. S. Teixeira Guilherme A. S. Pereira Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4065: Identification of Soybean Varieties Using Hyperspectral Imaging Coupled with Convolutional Neural Network
Yu He Feng Soybean variety is connected to stress resistance ability, as well as nutritional and commercial value. Near-infrared hyperspectral imaging was applied to classify three varieties of soybeans (Zhonghuang37, Zhonghuang41, and Zhonghuang55). Pixel-wise spectra were extracted and preprocessed, and average spectra were also obtained. Convolutional neural networks (CNN) using the average spectra and pixel-wise spectra of different numbers of soybeans were built. Pixel-wise CNN models obtained good performance predicting pixel-wise spectra and average spectra. With the increase of soybean numbers, performa...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Zhu Zhou Zhang Bao Wu Chu Yu He Feng Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4064: StarNAV: Autonomous Optical Navigation of a Spacecraft by the Relativistic Perturbation of Starlight
n Future space exploration missions require increased autonomy. This is especially true for navigation, where continued reliance on Earth-based resources is often a limiting factor in mission design and selection. In response to the need for autonomous navigation, this work introduces the StarNAV framework that may allow a spacecraft to autonomously navigate anywhere in the Solar System (or beyond) using only passive observations of naturally occurring starlight. Relativistic perturbations in the wavelength and direction of observed stars may be used to infer spacecraft velocity which, in turn, may be used for navigati...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: John A. Christian Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4066: Potential of Virtual Earth Observation Constellations in Archaeological Research
mitsis Earth observation sensors continually provide datasets with different spectral and spatial characteristics, while a series of pre- and postprocessing techniques are needed for calibration purposes. Nowadays, a variety of satellite images have become accessible to researchers, while big data cloud platforms allow them to deal with an extensive number of datasets. However, there is still difficulty related to these sensors meeting specific needs and challenges such as those of cultural heritage and supporting archaeological research world-wide. The harmonization and synergistic use of different sensors can be used...
Source: Sensors - September 20, 2019 Category: Biotechnology Authors: Agapiou Alexakis Hadjimitsis Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4039: Commercial Screen-Printed Electrodes Based on Carbon Nanomaterials for a Fast and Cost-Effective Voltammetric Determination of Paracetamol, Ibuprofen and Caffeine in Water Samples
-Cruz José Díaz-Cruz Carbon screen-printed electrode (SPCE), multi-walled carbon nanotubes modified screen-printed electrode (SPCNTE), carbon nanofibers modified screen-printed electrode (SPCNFE), and graphene modified screen-printed electrode (SPGPHE) were in a pioneer way tested as sensors for the simultaneous determination of the two most consumed pain-killers, paracetamol (PA) and ibuprofen (IB), and the stimulant caffeine (CF) in water by differential pulse voltammetry (DPV). Their analytical performances were compared, and the resulting sensitivities (2.50, 0.074, and 0.24 μA V mg−1 L for...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: N úria Serrano Òscar Castilla Cristina Ari ño M. Diaz-Cruz Jos é Díaz-Cruz Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4040: Constant-Modulus-Waveform Design for Multiple-Target Detection in Colocated MIMO Radar
Yang For improving the performance of multiple-target detection in a colocated multiple-input multiple-output (MIMO) radar system, a constant-modulus-waveform design method is presented in this paper. The proposed method consists of two steps: simultaneous multiple-transmit-beam design and constant-modulus-waveform design. In the first step, each transmit beam is controlled by an ideal orthogonal waveform and a weight vector. We optimized the weight vectors to maximize the detection probabilities of all targets or minimize the transmit power for the purpose of low intercept probability in the case of predefined worst ...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Bingfan Liu Baixiao Chen Minglei Yang Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4041: Thin Magnetically Permeable Targets for Inductive Sensing: Application to Limb Prosthetics
Joan E. Sanders The purpose of this research was to create a thin ferrous polymer composite to be used as a target for inductive sensing in limb prosthetics. Inductive sensors are used to monitor limb-to-socket distance in prosthetic sockets, which reflects socket fit. A styrene–ethylene–ethylene/propylene–styrene (SEEPS) polymer was mixed with iron powder at three concentrations (75, 77, 85 wt%), and thin disk-shaped samples were fabricated (0.50, 0,75, 1.00 mm thickness). For 85 wt% samples of 0.50 mm thickness, which proved the best combination of high signal strength and lo...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Ethan J. Weathersby Clement J. Gurrey Jake B. McLean Benjamin N. Sanders Brian G. Larsen Ryan Carter Joseph L. Garbini Joan E. Sanders Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4042: A Deep Learning Framework for Signal Detection and Modulation Classification
ihan Yang Deep learning (DL) is a powerful technique which has achieved great success in many applications. However, its usage in communication systems has not been well explored. This paper investigates algorithms for multi-signals detection and modulation classification, which are significant in many communication systems. In this work, a DL framework for multi-signals detection and modulation recognition is proposed. Compared to some existing methods, the signal modulation format, center frequency, and start-stop time can be obtained from the proposed scheme. Furthermore, two types of networks are built: (1) Single ...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Xiong Zha Hua Peng Xin Qin Guang Li Sihan Yang Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4043: Empirical Formulas for Estimating Backscattering and Absorption Coefficients in Complex Waters from Remote-Sensing Reflectance Spectra and Examples of Their Application
We present, among other things, an example of a simple semi-analytical algorithm using both new empirical formulas. This algorithm is a modified version of the well-known quasi-analytical algorithm (QAA), and it can improve the results obtained in optically complex waters. This algorithm allows one to estimate the full spectra of the backscattering and absorption coefficients, without the need for any additional a priori assumptions regarding the spectral shape of absorption by dissolved and suspended seawater constituents. (Source: Sensors)
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: S ławomir B. Woźniak Miros ław Darecki S ławomir Sagan Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4045: Cyber Situation Comprehension for IoT Systems based on APT Alerts and Logs Correlation
Chen With the emergence of the Advanced Persistent Threat (APT) attacks, many Internet of Things (IoT) systems have faced large numbers of potential threats with the characteristics of concealment, permeability, and pertinence. However, existing methods and technologies cannot provide comprehensive and prompt recognition of latent APT attack activities in the IoT systems. To address this problem, we propose an APT Alerts and Logs Correlation Method, named APTALCM and a framework of deploying APTALCM on the IoT system, where an edge computing architecture was used to achieve cyber situation comprehension without too mu...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Xiang Cheng Jiale Zhang Bing Chen Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4044: UWB/Binocular VO Fusion Algorithm Based on Adaptive Kalman Filter
de Lv Among the existing wireless indoor positioning systems, UWB (ultra-wideband) is one of the most promising solutions. However, the single UWB positioning system is affected by factors such as non-line of sight and multipath, and the navigation accuracy will decrease. In order to make up for the shortcomings of a single UWB positioning system, this paper proposes a scheme based on binocular VO (visual odometer) and UWB sensor fusion. In this paper, the original distance measurement data of UWB and the position information of binocular VO are merged by adaptive Kalman filter, and the structural design of the fusion ...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Qingxi Zeng Dehui Liu Chade Lv Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4046: Geometric Aberration Theory of Offner Imaging Spectrometers
nhao Li A third-order aberration theory has been developed for the Offner imaging spectrometer comprising an extended source; two concave mirrors; a convex diffraction grating; and an image plane. Analytic formulas of the spot diagram are derived for tracing rays through the system based on Fermat’s principle. The proposed theory can be used to discuss in detail individual aberrations of the system such as coma, spherical aberration and astigmatism, and distortion together with the focal conditions. It has been critically evaluated as well in a comparison with exact ray tracing constructed using the comme...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Meihong Zhao Yanxiu Jiang Shuo Yang Wenhao Li Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4047: Fault Feature Extraction and Diagnosis of Rolling Bearings Based on Enhanced Complementary Empirical Mode Decomposition with Adaptive Noise and Statistical Time-Domain Features
ngjian Wang In this paper, a novel method is proposed to enhance the accuracy of fault diagnosis for rolling bearings. First, an enhanced complementary empirical mode decomposition with adaptive noise (ECEEMDAN) method is proposed by determining two critical parameters, namely the amplitude of added white noise (AAWN) and the ensemble trails (ET). By introducing the concept of decomposition level, the optimal AAWN can be determined by judging the mutation of mutual information (MI) between adjacent intrinsic mode functions (IMFs). Furthermore, the ET is fixed at two to reduce the computational cost. This method can avo...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Liwei Zhan Fang Ma Jingjing Zhang Chengwei Li Zhenghui Li Tingjian Wang Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4048: Nanosystems, Edge Computing, and the Next Generation Computing Systems
mam It is widely recognized that nanoscience and nanotechnology and their subfields, such as nanophotonics, nanoelectronics, and nanomechanics, have had a tremendous impact on recent advances in sensing, imaging, and communication, with notable developments, including novel transistors and processor architectures. For example, in addition to being supremely fast, optical and photonic components and devices are capable of operating across multiple orders of magnitude length, power, and spectral scales, encompassing the range from macroscopic device sizes and kW energies to atomic domains and single-photon energies. The ...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Ali Passian Neena Imam Tags: Review Source Type: research

Sensors, Vol. 19, Pages 4049: Privacy Aware Incentivization for Participatory Sensing
Bouroche Abstract: Participatory sensing is a process whereby mobile device users (or participants) collect environmental data on behalf of a service provider who can then build a service based upon these data. To attract submissions of such data, the service provider will often need to incentivize potential participants by offering a reward. However, for the privacy conscious, the attractiveness of such rewards may be offset by the fact that the receipt of a reward requires users to either divulge their real identity or provide a traceable pseudonym. An incentivization mechanism must therefore facilitate data submissi...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Connolly Dusparic Iosifidis Bouroche Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4050: Enhancement of Multimodal Microwave-Ultrasound Breast Imaging Using a Deep-Learning Technique
We present a deep learning method used in conjunction with dual-modal microwave-ultrasound imaging to produce tomographic reconstructions of the complex-valued permittivity of numerical breast phantoms. We also assess tumor segmentation performance using the reconstructed permittivity as a feature. The contrast source inversion (CSI) technique is used to create the complex-permittivity images of the breast with ultrasound-derived tissue regions utilized as prior information. However, imaging artifacts make the detection of tumors difficult. To overcome this issue we train a convolutional neural network (CNN) that takes in,...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Vahab Khoshdel Ahmed Ashraf Joe LoVetri Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4051: Freeze-Damage Detection in Lemons Using Electrochemical Impedance Spectroscopy
Laguarda-Miró Lemon is the most sensitive citrus fruit to cold. Therefore, it is of capital importance to detect and avoid temperatures that could damage the fruit both when it is still in the tree and in its subsequent commercialization. In order to rapidly identify frost damage in this fruit, a system based on the electrochemical impedance spectroscopy technique (EIS) was used. This system consists of a signal generator device associated with a personal computer (PC) to control the system and a double-needle stainless steel electrode. Tests with a set of fruits both natural and subsequently frozen-thawed al...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Ochandio Fern ández Olgu ín Pinatti Masot Peris Laguarda-Mir ó Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4052: Polymer Fibers Covered by Soft Multilayered Films for Sensing Applications in Composite Materials
i Piotr Lesiak This paper presents the possibility of applying a soft polymer coating by means of a layer-by-layer (LbL) technique to highly birefringent polymer optical fibers designed for laminating in composite materials. In contrast to optical fibers made of pure silica glass, polymer optical fibers are manufactured without a soft polymer coating. In typical sensor applications, the absence of a buffer coating is an advantage. However, highly birefringent polymer optical fibers laminated in a composite material are much more sensitive to temperature changes than polymer optical fibers in a free space as a result ...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Dorian Nikoniuk Karolina Bednarska Maksymilian Sienkiewicz Grzegorz Krzesi ński Mateusz Olszyna Lars D ähne Tomasz R. Woli ński Piotr Lesiak Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4053: Detection of Hydraulic Phenomena in Francis Turbines with Different Sensors
za Egusquiza Nowadays, hydropower is demanded to provide flexibility and fast response into the electrical grid in order to compensate the non-constant electricity generation of other renewable sources. Hydraulic turbines are therefore demanded to work under off-design conditions more frequently, where different complex hydraulic phenomena appear, affecting the machine stability as well as reducing the useful life of its components. Hence, it is desirable to detect in real-time these hydraulic phenomena to assess the operation of the machine. In this paper, a large medium-head Francis turbine was selected for this p...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Valent ín Presas Valero Egusquiza Egusquiza Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4054: Recurrent Neural Network for Inertial Gait User Recognition in Smartphones
wa Wu In this article, a gait recognition algorithm is presented based on the information obtained from inertial sensors embedded in a smartphone, in particular, the accelerometers and gyroscopes typically embedded on them. The algorithm processes the signal by extracting gait cycles, which are then fed into a Recurrent Neural Network (RNN) to generate feature vectors. To optimize the accuracy of this algorithm, we apply a random grid hyperparameter selection process followed by a hand-tuning method to reach the final hyperparameter configuration. The different configurations are tested on a public database with 744...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Fernandez-Lopez Liu-Jimenez Kiyokawa Wu Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4055: Decision-Making for the Autonomous Navigation of Maritime Autonomous Surface Ships Based on Scene Division and Deep Reinforcement Learning
Chen This research focuses on the adaptive navigation of maritime autonomous surface ships (MASSs) in an uncertain environment. To achieve intelligent obstacle avoidance of MASSs in a port, an autonomous navigation decision-making model based on hierarchical deep reinforcement learning is proposed. The model is mainly composed of two layers: the scene division layer and an autonomous navigation decision-making layer. The scene division layer mainly quantifies the sub-scenarios according to the International Regulations for Preventing Collisions at Sea (COLREG). This research divides the navigational situation of a ...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Zhang Wang Liu Chen Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4056: Geometry Optimisation of a Hall-Effect-Based Soft Fingertip for Estimating Orientation of Thin Rectangular Objects
We present a method of investigating the optimal geometrical design of a cylindrical soft sensor to increase its sensitivity. The finite element model of a soft fingertip was constructed in Abaqus with two design variables, i.e., hollow radius and magnet position. Then, the model was imported into Isight, with the maximisation of magnet displacement as the objective function. We found that the optimal design was at the boundary of the parameter design space. Four fingertips were fabricated with one intuitive, one optimal, and two optional sets of parameters. Experiments were performed, and object orientation was estimated ...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Rosle Wang Hirai Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4034: Ubiquitous Computing and Ambient Intelligence —UCAmI
Sensors, Vol. 19, Pages 4034: Ubiquitous Computing and Ambient Intelligence—UCAmI Sensors doi: 10.3390/s19184034 Authors: Macarena Espinilla Vladimir Villarreal Ian McChesney The Ubiquitous Computing (UC) idea envisioned by Weiser in 1991 [...] (Source: Sensors)
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Macarena Espinilla Vladimir Villarreal Ian McChesney Tags: Editorial Source Type: research

Sensors, Vol. 19, Pages 4035: A Machine Learning Approach to Bridge-Damage Detection Using Responses Measured on a Passing Vehicle
ute;n Clarke This paper proposes a new two-stage machine learning approach for bridge damage detection using the responses measured on a passing vehicle. In the first stage, an artificial neural network (ANN) is trained using the vehicle responses measured from multiple passes (training data set) over a healthy bridge. The vehicle acceleration or Discrete Fourier Transform (DFT) spectrum of the acceleration is used. The vehicle response is predicted from its speed for multiple passes (monitoring data set) over the bridge. Root-mean-square error is used to calculate the prediction error, which indicates the differences ...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Abdollah Malekjafarian Fatemeh Golpayegani Callum Moloney Siobh án Clarke Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4036: AEF: Adaptive En-Route Filtering to Extend Network Lifetime in Wireless Sensor Networks
nyereye Static sink-based wireless sensor networks (WSNs) suffer from an energy-hole problem. This incurs as the rate of energy consumption on sensor nodes around sinks and on critical paths is considerably faster. State-of-the-art en-routing filtering schemes save energy by countering false report injection attacks. In addition to their unique limitations, these schemes generally do not examine energy awareness in underlying routing. Mostly, these security methods are based on a fixed filtering capacity, unable to respond to changes in attack intensity. Therefore, these limitations cause network partition(s), exhibiti...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Muhammad K. Shahzad S. M. Riazul Islam Kyung-Sup Kwak Lewis Nkenyereye Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4037: Reducing the Cost of Implementing Filters in LoRa Devices
e Henry This paper presents two methods to optimize LoRa (Low-Power Long-Range) devices so that implementing multiplier-less pulse shaping filters is more economical. Basic chirp waveforms can be generated more efficiently using the method of chirp segmentation so that only a quarter of the samples needs to be stored in the ROM. Quantization can also be applied to the basic chirp samples in order to reduce the number of unique input values to the filter, which in turn reduces the size of the lookup table for multiplier-less filter implementation. Various tests were performed on a simulated LoRa system in order to evalu...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Shania Stewart Ha H. Nguyen Robert Barton Jerome Henry Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4038: Multi-Layer IoT Security Framework for Ambient Intelligence Environments
a Matei Ambient intelligence is a new paradigm in the Internet of Things (IoT) world that brings smartness to living environments to make them more sensitive; adaptive; and personalized to human needs. A critical area where ambient intelligence can be used is health and social care; where it can improve and sustain the quality of life without increasing financial costs. The adoption of this new paradigm for health and social care largely depends on the technology deployed (sensors and wireless networks), the software used for decision-making and the security, privacy and reliability of the information. IoT sensors and ...
Source: Sensors - September 19, 2019 Category: Biotechnology Authors: Ion Bica Bogdan-Cosmin Chifor Ștefan-Ciprian Arseni Ioana Matei Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4017: Elemental: An Open-Source Wireless Hardware and Software Platform for Building Energy and Indoor Environmental Monitoring and Control
ent Stephens This work demonstrates an open-source hardware and software platform for monitoring the performance of buildings, called Elemental, that is designed to provide data on indoor environmental quality, energy usage, HVAC operation, and other factors to its users. It combines: (i) custom printed circuit boards (PCBs) with RFM69 frequency shift keying (FSK) radio frequency (RF) transceivers for wireless sensors, control nodes, and USB gateway, (ii) a Raspberry Pi 3B with custom firmware acting as either a centralized or distributed backhaul, and (iii) a custom dockerized application for the backend called Brood ...
Source: Sensors - September 18, 2019 Category: Biotechnology Authors: Akram Syed Ali Christopher Cot é Mohammad Heidarinejad Brent Stephens Tags: Article Source Type: research

Sensors, Vol. 19, Pages 4018: Ultrathin Tunable Lens Based on Boundary Tension Effect
Qun Hao Solid and liquid lenses are commonly used in optical design. Such lenses have suitable thicknesses due to their working principle and processing mode. Thus, zoom optical systems comprising solid and liquid lenses are extremely large. This work presents a new ultrathin tunable lens (UTL) comprising two liquid film lenses (LFLs) obtained through aspheric deformation and produced from the surface of a micro-liquid under gravity and boundary tension. The UTL can flexibly change focal lengths between positive and negative lenses when the device thickness is merely 2.15 mm. The proposed lens has the advantages of s...
Source: Sensors - September 18, 2019 Category: Biotechnology Authors: Ao Yang Jie Cao Fanghua Zhang Yang Cheng Qun Hao Tags: Article Source Type: research