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https://www.readbyqxmd.com/read/28441329/implementation-of-an-electronic-ionosonde-to-monitor-the-earth-s-ionosphere-via-a-projected-column-through-usrp
#1
Jhon Jairo Barona Mendoza, Carlos Fernando Quiroga Ruiz, Carlos Rafael Pinedo Jaramillo
This document illustrates the processes carried out for the construction of an ionospheric sensor or ionosonde, from a universal software radio peripheral (USRP), and its programming using GNU-Radio and MATLAB. The development involved the in-depth study of the characteristics of the ionosphere, to apply the corresponding mathematical models used in the radar-like pulse compression technique and matched filters, among others. The sensor operates by firing electromagnetic waves in a frequency sweep, which are reflected against the ionosphere and are received on its return by the receiver of the instrument, which calculates the reflection height through the signal offset...
April 25, 2017: Sensors
https://www.readbyqxmd.com/read/28431363/nanomaterial-based-electrochemical-sensors-for-arsenic-a-review
#2
REVIEW
Sureshkumar Kempahanumakkagari, Akash Deep, Ki-Hyun Kim, Suresh Kumar Kailasa, Hye-On Yoon
The existence of arsenic in the environment poses severe global health threats. Considering its toxicity, the sensing of arsenic is extremely important. Due to the complexity of environmental and biological samples, many of the available detection methods for arsenic have serious limitations on selectivity and sensitivity. To improve sensitivity and selectivity and to circumvent interferences, different electrode systems have been developed based on surface modification with nanomaterials including carbonaceous nanomaterials, metallic nanoparticles (MNPs), metal nanotubes (MNTs), and even enzymes...
April 13, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28430119/influence-of-wind-speed-on-rgb-d-images-in-tree-plantations
#3
Dionisio Andújar, José Dorado, José María Bengochea-Guevara, Jesús Conesa-Muñoz, César Fernández-Quintanilla, Ángela Ribeiro
Weather conditions can affect sensors' readings when sampling outdoors. Although sensors are usually set up covering a wide range of conditions, their operational range must be established. In recent years, depth cameras have been shown as a promising tool for plant phenotyping and other related uses. However, the use of these devices is still challenged by prevailing field conditions. Although the influence of lighting conditions on the performance of these cameras has already been established, the effect of wind is still unknown...
April 21, 2017: Sensors
https://www.readbyqxmd.com/read/28426336/effect-of-laser-energy-and-tip-insertion-depth-on-the-pressure-generated-outside-the-apical-foramen-during-er-yag-laser-activated-root-canal-irrigation
#4
Kanako Yao, Kazuhisa Satake, Satoshi Watanabe, Arata Ebihara, Chihiro Kobayashi, Takashi Okiji
OBJECTIVE: The risk of extrusion of irritative irrigants into the extraradicular tissue should be minimized during root canal irrigation. This study aimed to examine the pressure generated outside the apex during Er:YAG laser-activated irrigation (LAI) in comparison with passive ultrasonic irrigation (PUI) and conventional syringe irrigation (SI). BACKGROUND DATA: LAI is reported to be efficient for root canal debridement, whereas the apical pressure generated during LAI has not been investigated in detail...
April 20, 2017: Photomedicine and Laser Surgery
https://www.readbyqxmd.com/read/28425091/marine-bioluminescence-measurement-by-a-classical-light-sensor-and-related-foraging-behaviour-of-a-deep-diving-predator
#5
Jade Vacquié-Garcia, Jérôme Mallefet, Frédéric Bailleul, Baptiste Picard, Christophe Guinet
Bioluminescence is produced by a broad range of organisms for defense, predation or communication purposes. Southern elephant seal (SES) vision is adapted to low intensity light with a peak sensitivity, matching the wavelength emitted by myctophid species, one of the main prey of female SES. A total of 11 satellite-tracked female SES were equipped with a Time-Depth-Light 3D-accelerometers (TDR10-X) in order to assess whether bioluminescence could be used by SES to locate their prey. First, we demonstrated experimentally that the TDR10-X light sensor was sensitive enough to detect natural bioluminescence; however, we highlighted a low distance detection of the sensor...
April 20, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28420155/new-compact-3-dimensional-shape-descriptor-for-a-depth-camera-in-indoor-environments
#6
Hyukdoo Choi, Euntai Kim
This study questions why existing local shape descriptors have high dimensionalities (up to hundreds) despite simplicity of local shapes. We derived an answer from a historical context and provided an alternative solution by proposing a new compact descriptor. Although existing descriptors can express complicated shapes and depth sensors have been improved, complex shapes are rarely observed in an ordinary environment and a depth sensor only captures a single side of a surface with noise. Therefore, we designed a new descriptor based on principal curvatures, which is compact but practically useful...
April 16, 2017: Sensors
https://www.readbyqxmd.com/read/28414454/novel-soil-profile-sensing-to-monitor-organic-c-stocks-and-condition
#7
Raphael A Viscarra Rossel, Craig R Lobsey, Chris Sharman, Paul Flick, Gordon McLachlan
Soil information is needed for environmental monitoring to address current concerns over food, water and energy securities, land degradation and climate change. We developed the {\sc Soil Condition ANalyses System (SCANS)} to help address these needs. It integrates an automated soil core sensing system (CSS) with statistical analytics and modelling to enable the characterisation of soil at fine depth resolutions and across landscapes. The CSS's sensors include a gamma-ray densitometer to measure bulk density, digital cameras to image the measured soil and a visible--near infrared (vis--NIR) spectrometer to measure iron oxides and clay mineralogy...
April 17, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28398224/inertial-sensor-based-robust-gait-analysis-in-non-hospital-settings-for-neurological-disorders
#8
Can Tunca, Nezihe Pehlivan, Nağme Ak, Bert Arnrich, Gülüstü Salur, Cem Ersoy
The gold standards for gait analysis are instrumented walkways and marker-based motion capture systems, which require costly infrastructure and are only available in hospitals and specialized gait clinics. Even though the completeness and the accuracy of these systems are unquestionable, a mobile and pervasive gait analysis alternative suitable for non-hospital settings is a clinical necessity. Using inertial sensors for gait analysis has been well explored in the literature with promising results. However, the majority of the existing work does not consider realistic conditions where data collection and sensor placement imperfections are imminent...
April 11, 2017: Sensors
https://www.readbyqxmd.com/read/28397759/a-high-spatial-resolution-depth-sensing-method-based-on-binocular-structured-light
#9
Huimin Yao, Chenyang Ge, Jianru Xue, Nanning Zheng
Depth information has been used in many fields because of its low cost and easy availability, since the Microsoft Kinect was released. However, the Kinect and Kinect-like RGB-D sensors show limited performance in certain applications and place high demands on accuracy and robustness of depth information. In this paper, we propose a depth sensing system that contains a laser projector similar to that used in the Kinect, and two infrared cameras located on both sides of the laser projector, to obtain higher spatial resolution depth information...
April 8, 2017: Sensors
https://www.readbyqxmd.com/read/28392689/surface-plasmon-enhanced-fluorescence-on-au-nanohole-array-for-prostate-specific-antigen-detection
#10
Qingwen Zhang, Lin Wu, Ten It Wong, Jinling Zhang, Xiaohu Liu, Xiaodong Zhou, Ping Bai, Bo Liedberg, Yi Wang
Localized surface plasmon (LSP) has been widely applied for the enhancement of fluorescence emission for biosensing owing to its potential for strong field enhancement. However, due to its small penetration depth, LSP offers limited fluorescence enhancement over a whole sensor chip and, therefore, insufficient sensitivity for the detection of biomolecules, especially large molecules. We demonstrate the simultaneous excitation of LSP and propagating surface plasmon (PSP) on an Au nanohole array under Kretschmann configuration for the detection of prostate-specific antigen with a sandwich immunoassay...
2017: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/28387633/smart-bioimpedance-controlled-craniotomy-concept-and-first-experiments
#11
Annegret Niesche, Meiko Müller, Fritz Ehreiser, Daniel Teichmann, Steffen Leonhardt, Klaus Radermacher
Craniotomy is part of many neurosurgical interventions to create surgical access to intracranial structures. The procedure conventionally bears a high risk of unintended dural tears or damage of the soft tissue underneath the bone. A new synergistically controlled instrument has recently been introduced to address this problem by combining a soft tissue preserving saw with an automatic cutting depth control. Many approaches are known to obtain the information required on the local bone thickness. However, they suffer from unsatisfactory robustness against disturbances occurring during surgery and many approaches require additional intra- or preoperative steps in the workflow...
March 1, 2017: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine
https://www.readbyqxmd.com/read/28380803/highly-sensitive-wide-dynamic-range-displacement-sensor-combining-chromatic-confocal-system-and-phase-sensitive-spectral-optical-coherence-tomography
#12
Bo Dong, Yun Zhang, Wucong Zhang, Zhaoshui He, Shengli Xie, Yanzhou Zhou
A displacement sensor with nanometer-sensitivity and a submillimeter dynamic range is proposed. It integrates a chromatic confocal system and phase-sensitive spectral optical coherence tomography (PhS-SOCT) into the fiber-based Michelson interferometer and codes interference and confocal signals with spectral multiplexing. A displacement is evaluated using depth-resolved phase information decoded from the interference signal, which is unwrapped based on the position information decoded from the confocal signal...
March 6, 2017: Optics Express
https://www.readbyqxmd.com/read/28376811/smart-homes-private-homes-an-empirical-study-of-technology-researchers-perceptions-of-ethical-issues-in-developing-smart-home-health-technologies
#13
Giles Birchley, Richard Huxtable, Madeleine Murtagh, Ruud Ter Meulen, Peter Flach, Rachael Gooberman-Hill
BACKGROUND: Smart-home technologies, comprising environmental sensors, wearables and video are attracting interest in home healthcare delivery. Development of such technology is usually justified on the basis of the technology's potential to increase the autonomy of people living with long-term conditions. Studies of the ethics of smart-homes raise concerns about privacy, consent, social isolation and equity of access. Few studies have investigated the ethical perspectives of smart-home engineers themselves...
April 4, 2017: BMC Medical Ethics
https://www.readbyqxmd.com/read/28372436/three-dimensional-measurement-with-an-electrically-tunable-focused-plenoptic-camera
#14
Yu Lei, Qing Tong, Zhaowei Xin, Dong Wei, Xinyu Zhang, Jing Liao, Haiwei Wang, Changsheng Xie
A liquid crystal microlens array (LCMLA) with an arrayed microhole pattern electrode based on nematic liquid crystal materials using a fabrication method including traditional UV-photolithography and wet etching is presented. Its focusing performance is measured under different voltage signals applied between the electrodes of the LCMLA. The experimental outcome shows that the focal length of the LCMLA can be tuned easily by only changing the root mean square value of the voltage signal applied. The developed LCMLA is further integrated with a main lens and an imaging sensor to construct a LCMLA-based focused plenoptic camera (LCFPC) prototype...
March 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28372041/vertical-line-array-measurements-of-ambient-noise-in-the-north-pacific
#15
Mehdi Farrokhrooz, Kathleen E Wage, Matthew A Dzieciuch, Peter F Worcester
Shipping noise and wind are the dominant sources of ocean noise in the frequency band between 20 and 500 Hz. This paper analyzes noise in that band using data from the SPICEX experiment, which took place in the North Pacific in 2004-2005, and compares the results with other North Pacific experiments. SPICEX included vertical arrays with sensors above and below the surface conjugate depth, facilitating an analysis of the depth dependence of ambient noise. The paper includes several key results. First, the 2004-05 noise levels at 50 Hz measured in SPICEX had not increased relative to levels measured by Morris [(1978)...
March 2017: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/28368842/robust-gait-recognition-by-integrating-inertial-and-rgbd-sensors
#16
Qin Zou, Lihao Ni, Qian Wang, Qingquan Li, Song Wang
Gait has been considered as a promising and unique biometric for person identification. Traditionally, gait data are collected using either color sensors, such as a CCD camera, depth sensors, such as a Microsoft Kinect, or inertial sensors, such as an accelerometer. However, a single type of sensors may only capture part of the dynamic gait features and make the gait recognition sensitive to complex covariate conditions, leading to fragile gait-based person identification systems. In this paper, we propose to combine all three types of sensors for gait data collection and gait recognition, which can be used for important identification applications, such as identity recognition to access a restricted building or area...
March 29, 2017: IEEE Transactions on Cybernetics
https://www.readbyqxmd.com/read/28368820/robust-non-rigid-motion-tracking-and-surface-reconstruction-using-l-0-regularization
#17
Kaiwen Guo, Feng Xu, Yangang Wang, Yebin Liu, Qionghai Dai
We present a new motion tracking technique to robustly reconstruct non-rigid geometries and motions from a single view depth input recorded by a consumer depth sensor. The idea is based on the observation that most non-rigid motions (especially human-related motions) are intrinsically involved in articulate motion subspace. To take this advantage, we propose a novel L0 based motion regularizer with an iterative solver that implicitly constrains local deformations with articulate structures, leading to reduced solution space and physical plausible deformations...
March 28, 2017: IEEE Transactions on Visualization and Computer Graphics
https://www.readbyqxmd.com/read/28345046/canopy-near-infrared-reflectance-and-terrestrial-photosynthesis
#18
Grayson Badgley, Christopher B Field, Joseph A Berry
Global estimates of terrestrial gross primary production (GPP) remain highly uncertain, despite decades of satellite measurements and intensive in situ monitoring. We report a new approach for quantifying the near-infrared reflectance of terrestrial vegetation (NIRV). NIRV provides a foundation for a new approach to estimate GPP that consistently untangles the confounding effects of background brightness, leaf area, and the distribution of photosynthetic capacity with depth in canopies using existing moderate spatial and spectral resolution satellite sensors...
March 2017: Science Advances
https://www.readbyqxmd.com/read/28343303/can-real-time-rgbd-enhance-intraoperative-cone-beam-ct
#19
Javad Fotouhi, Bernhard Fuerst, Wolfgang Wein, Nassir Navab
PURPOSE: Cone-Beam Computed Tomography (CBCT) is an important 3D imaging technology for orthopedic, trauma, radiotherapy guidance, angiography, and dental applications. The major limitation of CBCT is the poor image quality due to scattered radiation, truncation, and patient movement. In this work, we propose to incorporate information from a co-registered Red-Green-Blue-Depth (RGBD) sensor attached near the detector plane of the C-arm to improve the reconstruction quality, as well as correcting for undesired rigid patient movement...
March 25, 2017: International Journal of Computer Assisted Radiology and Surgery
https://www.readbyqxmd.com/read/28324936/a-preliminary-study-on-multi-wavelength-ppg-based-pulse-transit-time-detection-for-cuffless-blood-pressure-measurement
#20
Jing Liu, Yuan-Ting Zhang, Xiao-Rong Ding, Wen-Xuan Dai, Ni Zhao
Pulse transit time (PTT) has been widely studied as an index of blood pressure (BP) changes. In recent years, some prototypes of PTT-based wearable BP measurement devices have been developed, which can relieve users from the discomfort caused by the inflating cuff used in auscultatory and oscillometric BP measurement techniques. However, in the common practice for PTT detection, multi-site sensor implementation on human body is required, making it difficult for the integration of wearable devices. Since multi-wavelength (MW) photoplethysmogram (PPG) signals carry blood pulsation information of different blood vessels embedded in different skin depths, the time difference between different wavelength PPG signals collected at the same body site can be treated as a special PTT on a short length of blood vessels beneath the skin...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
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