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Vyacheslav A Trofimov, Svetlana A Varentsova
We have studied the spectral resolution influence on the accuracy of the substance detection and identification at using a broadband THz pulse measured under real conditions (at a distance of more than 3 m from a THz emitter in ambient air with a relative humidity of about 50%). We show that increasing spectral resolution leads to manifestation of small-scale perturbations (random fluctuations) in the signal spectrum caused by the influence of the environment or the sample structure. Decreasing the spectral resolution allows us to exclude from consideration this small-scale modulation of the signal as well as to detect the water vapor absorption frequencies...
December 12, 2017: Sensors
Hui Du, Xiaobo Chen, Juntong Xi, Chengyi Yu, Bao Zhao
Large-scale surfaces are prevalent in advanced manufacturing industries, and 3D profilometry of these surfaces plays a pivotal role for quality control. This paper proposes a novel and flexible large-scale 3D scanning system assembled by combining a robot, a binocular structured light scanner and a laser tracker. The measurement principle and system construction of the integrated system are introduced. A mathematical model is established for the global data fusion. Subsequently, a robust method is introduced for the establishment of the end coordinate system...
December 12, 2017: Sensors
Javier Medina Quero, María Rosa Fernández Olmo, María Dolores Peláez Aguilera, Macarena Espinilla Estévez
Cardiac rehabilitation is a key program which significantly reduces the mortality in at-risk patients with ischemic heart disease; however, there is a lack of accessibility to these programs in health centers. To resolve this issue, home-based programs for cardiac rehabilitation have arisen as a potential solution. In this work, we present an approach based on a new generation of wrist-worn devices which have improved the quality of heart rate sensors and applications. Real-time monitoring of rehabilitation sessions based on high-quality clinical guidelines is embedded in a wearable application...
December 12, 2017: Sensors
Budi Wibowotomo, Jong-Bang Eun, Jong Il Rhee
Saccharin is a powerfully sweet nonnutritive sweetener that has been approved for food-processing applications within the range of 100-1200 mg/kg. A simple, rapid, and cost-effective sequential injection analysis (SIA) technique was developed to determine the saccharin level. This method is based on the reaction of saccharin with p-chloranil in an ethanol medium with a hydrogen peroxide (H₂O₂) acceleration, and the resultant violet-red compound was detected using a UV-Vis spectrophotometer at λmax = 420 nm...
December 12, 2017: Sensors
Caixia Song
Vehicular Ad Hoc Networks (VANETs) employ multichannel to provide a variety of safety and non-safety applications, based on the IEEE 802.11p and IEEE 1609.4 protocols. The safety applications require timely and reliable transmissions, while the non-safety applications require efficient and high throughput. In the IEEE 1609.4 protocol, operating interval is divided into alternating Control Channel (CCH) interval and Service Channel (SCH) interval with an identical length. During the CCH interval, nodes transmit safety-related messages and control messages, and Enhanced Distributed Channel Access (EDCA) mechanism is employed to allow four Access Categories (ACs) within a station with different priorities according to their criticality for the vehicle's safety...
December 12, 2017: Sensors
Guokai Shi, Tingfa Xu, Jie Guo, Jiqiang Luo, Yuankun Li
Most existing correlation filter-based tracking algorithms, which use fixed patches and cyclic shifts as training and detection measures, assume that the training samples are reliable and ignore the inconsistencies between training samples and detection samples. We propose to construct and study a consistently sampled correlation filter with space anisotropic regularization (CSSAR) to solve these two problems simultaneously. Our approach constructs a spatiotemporally consistent sample strategy to alleviate the redundancies in training samples caused by the cyclical shifts, eliminate the inconsistencies between training samples and detection samples, and introduce space anisotropic regularization to constrain the correlation filter for alleviating drift caused by occlusion...
December 12, 2017: Sensors
Naresh Kumar Ravichandran, Ruchire Eranga Wijesinghe, Seung-Yeol Lee, Muhammad Faizan Shirazi, Hee-Young Jung, Mansik Jeon, Jeehyun Kim
We demonstrate that optical coherence tomography (OCT) is a plausible optical tool for in vivo detection of plant seeds and its morphological changes during growth. To investigate the direct impact of salt stress on seed germination, the experiment was conducted using Capsicum annuum seeds that were treated with different molar concentrations of NaCl. To determine the optimal concentration for the seed growth, the seeds were monitored for nine consecutive days. In vivo two-dimensional OCT images of the treated seeds were obtained and compared with the images of seeds that were grown using sterile distilled water...
December 12, 2017: Sensors
Shan-Bin Sun, Yuan-Yuan He, Si-Da Zhou, Zhen-Jiang Yue
Measurement of dynamic responses plays an important role in structural health monitoring, damage detection and other fields of research. However, in aerospace engineering, the physical sensors are limited in the operational conditions of spacecraft, due to the severe environment in outer space. This paper proposes a virtual sensor model with partial vibration measurements using a convolutional neural network. The transmissibility function is employed as prior knowledge. A four-layer neural network with two convolutional layers, one fully connected layer, and an output layer is proposed as the predicting model...
December 12, 2017: Sensors
Tiziana Segreto, Alessandra Caggiano, Sara Karam, Roberto Teti
Nickel-Titanium (Ni-Ti) alloys are very difficult-to-machine materials causing notable manufacturing problems due to their unique mechanical properties, including superelasticity, high ductility, and severe strain-hardening. In this framework, the aim of this paper is to assess the machinability of Ni-Ti alloys with reference to turning processes in order to realize a reliable and robust in-process identification of machinability conditions. An on-line sensor monitoring procedure based on the acquisition of vibration signals was implemented during the experimental turning tests...
December 12, 2017: Sensors
Ieva Migliniene, Vytautas Ostasevicius, Rimvydas Gaidys, Rolanas Dauksevicius, Giedrius Janusas, Vytautas Jurenas, Povilas Krasauskas
This paper proposes an approach for designing an efficient vibration energy harvester based on a vibro-impacting piezoelectric microcantilever with a geometric shape that has been rationally modified in accordance with results of dynamic optimization. The design goal is to increase the amplitudes of higher-order vibration modes induced during the vibro-impact response of the piezoelectric transducer, thereby providing a means to improve the energy conversion efficiency and power output. A rational configuration of the energy harvester is proposed and it is demonstrated that the new design retains essential modal characteristics of the optimal microcantilever structures, further providing the added benefit of less costly fabrication...
December 12, 2017: Sensors
Jing Rao, Madis Ratassepp, Danylo Lisevych, Mahadhir Hamzah Caffoor, Zheng Fan
Corrosion is a major safety and economic concern to various industries. In this paper, a novel ultrasonic guided wave tomography (GWT) system based on self-designed piezoelectric sensors is presented for on-line corrosion monitoring of large plate-like structures. Accurate thickness reconstruction of corrosion damages is achieved by using the dispersive regimes of selected guided waves and a reconstruction algorithm based on full waveform inversion (FWI). The system makes use of an array of miniaturised piezoelectric transducers that are capable of exciting and receiving highly dispersive A0 Lamb wave mode at low frequencies...
December 12, 2017: Sensors
Zonghua Zhang, Yuemin Wang, Shujun Huang, Yue Liu, Caixia Chang, Feng Gao, Xiangqian Jiang
The fast development in the fields of integrated circuits, photovoltaics, the automobile industry, advanced manufacturing, and astronomy have led to the importance and necessity of quickly and accurately obtaining three-dimensional (3D) shape data of specular surfaces for quality control and function evaluation. Owing to the advantages of a large dynamic range, non-contact operation, full-field and fast acquisition, high accuracy, and automatic data processing, phase-measuring deflectometry (PMD, also called fringe reflection profilometry) has been widely studied and applied in many fields...
December 7, 2017: Sensors
Eun Hye Kim, Eun-Song Lee, Dong Yun Lee, Young-Pil Kim
Despite high relevance of tear osmolarity and eye abnormality, numerous methods for detecting tear osmolarity rely upon expensive osmometers. We report a reliable method for simply determining sodium ion-based osmolarity in artificial tears using sequential DNAzymes. When sodium ion-specific DNAzyme and peroxidase-like DNAzyme were used as a sensing and detecting probe, respectively, the concentration of Na⁺ in artificial tears could be measured by absorbance or fluorescence intensity, which was highly correlated with osmolarity over the diagnostic range (R² > 0...
December 7, 2017: Sensors
Sayef Azad Sakin, Md Abdur Razzaque, Mohammad Mehedi Hassan, Atif Alamri, Nguyen H Tran, Giancarlo Fortino
Ensuring self-coexistence among IEEE 802.22 networks is a challenging problem owing to opportunistic access of incumbent-free radio resources by users in co-located networks. In this study, we propose a fully-distributed non-cooperative approach to ensure self-coexistence in downlink channels of IEEE 802.22 networks. We formulate the self-coexistence problem as a mixed-integer non-linear optimization problem for maximizing the network data rate, which is an NP-hard one. This work explores a sub-optimal solution by dividing the optimization problem into downlink channel allocation and power assignment sub-problems...
December 7, 2017: Sensors
Eric G Stevens, Jeffrey A Clayhold, Hung Doan, Robert P Fabinski, Jaroslav Hynecek, Stephen L Kosman, Christopher Parks
This paper describes recent process modifications made to enhance the performance of interline and electron-multiplying charge-coupled-device (EMCCD) image sensors. By use of MeV ion implantation, quantum efficiency in the NIR region of the spectrum was increased by 2×, and image smear was reduced by 6 dB. By reducing the depth of the shallow photodiode (PD) implants, the photodiode-to-vertical-charge-coupled-device (VCCD) transfer gate voltage required for no-lag operation was reduced by 3 V, and the electronic shutter voltage was reduced by 9 V...
December 7, 2017: Sensors
Nan Li, Egor M Larin, Kagan Kerman
Adrenocorticotropic hormone (ACTH) plays an essential role in regulating corticosteroid hormone production, which has important functions in a myriad of critical physiological functions. In this proof-of-concept study, a miniaturized immunosensor was developed for the highly sensitive detection of ACTH using electrochemical impedance spectroscopy (EIS) in connection with disposable screen-printed gold electrodes (SPGEs). A film of 3,3'-dithiobis[sulfosuccinimidylpropionate] (DTSSP) was prepared to immobilize anti-ACTH antibodies covalently on the nanostructured SPGE surface...
December 7, 2017: Sensors
Qiu Wang, Hong-Ning Dai, Chak Fong Cheang, Hao Wang
Extensive attention has been given to the use of cognitive radio technology in underwater acoustic networks since the acoustic spectrum became scarce due to the proliferation of human aquatic activities. Most of the recent studies on underwater cognitive acoustic networks (UCANs) mainly focus on spectrum management or protocol design. Few efforts have addressed the quality-of-service (QoS) of UCANs. In UCANs, secondary users (SUs) have lower priority to use acoustic spectrum than primary users (PUs) with higher priority to access spectrum...
December 7, 2017: Sensors
Shih-Hsiang Hsu, Kuo-Wei Chuang, Ci-Syu Chen, Ching-Yu Lin, Che-Chang Chang
The spectral linewidth from two cross-correlated fiber Bragg gratings (FBGs) are interrogated and characterized using a delayed self-homodyne method for fiber strain sensing. This approach employs a common higher frequency resolution instead of wavelength. A sensitivity and resolution of 166 MHz/με and 50 nε were demonstrated from 4 GHz spectral linewidth characterization on the electric spectrum analyzer. A 10 nε higher resolution can be expected through random noise analyses when the spectral linewidth from two FBG correlations is reduced to 1 GHz...
December 7, 2017: Sensors
Yankun Wang, Hong Fan, Ruizhi Chen
Spatial relationships are crucial to spatial knowledge representation, such as positioning localities. However, minimal attention has been devoted to positioning localities indoors with locality description. Distance and direction relations are generally used when positioning localities, namely, translating descriptive localities into spatially explicit ones. We propose a joint probability function to model locality distribution to address the uncertainty of positioning localities. The joint probability function consists of distance and relative direction membership functions...
December 7, 2017: Sensors
Kwok L Chung, Chunwei Zhang, Yuanyuan Li, Li Sun, Mohamed Ghannam
This research article presents dual-frequency correlation models for predicting the growth of elasticity and flexural strength of engineered cementitious composites (ECCs) using microwave nondestructive inspection technique. Parallel measurements of microwave properties and mechanical properties of ECC specimens were firstly undertaken in the sense of cross-disciplinary experiments. Regression models were developed via means of nonlinear regression to the measured data. The purpose of the study is: (i) to monitor the flexural strength and elasticity growth; and (ii) to predict their mature values under the influence of different initial water contents, via microwave effective conductance at early ages...
December 6, 2017: Sensors
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