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Depth sensor

Vlad Cârlescu, Dumitru N Olaru, Gheorghe Prisăcaru, Cezar Oprişan, José Machado
In this paper, the authors present a new methodology to study the viscoelastic behaviour of the human finger. The methodology is based on experimental research consisting of a finger's indentation with a small steel cylindrical object for various indentation speeds. The tests were realized on a CETR UMT-2 Tribometer for indentation speed between 0.02 mm/s and 4 mm/s with a normal load of up to 22 N. Using the force-deformation diagrams recorded at the smallest indentation speed determined the elastic modulus of the human finger according to an adapted Hertzian model...
May 23, 2017: Sensors
Torben Schulze, Kai Mattern, Eike Früh, Lars Hecht, Ingo Rustenbeck, Andreas Dietzel
Microfluidic perfusion systems (MPS) are well suited to perform multiparametric measurements with small amounts of tissue to function as an Organ on Chip device (OOC). Such microphysiolgical characterization is particularly valuable in research on the stimulus-secretion-coupling of pancreatic islets. Pancreatic islets are fully functional competent mini-organs, which serve as fuel sensors and transduce metabolic activity into rates of hormone secretion. To enable the simultaneous measurement of fluorescence and oxygen consumption we designed a microfluidic perfusion system from borosilicate glass by 3D femtosecond laser ablation...
September 2017: Biomedical Microdevices
Walid Darwish, Shenjun Tang, Wenbin Li, Wu Chen
Commercial RGB-D sensors such as Kinect and Structure Sensors have been widely used in the game industry, where geometric fidelity is not of utmost importance. For applications in which high quality 3D is required, i.e., 3D building models of centimeter‑level accuracy, accurate and reliable calibrations of these sensors are required. This paper presents a new model for calibrating the depth measurements of RGB-D sensors based on the structured light concept. Additionally, a new automatic method is proposed for the calibration of all RGB-D parameters, including internal calibration parameters for all cameras, the baseline between the infrared and RGB cameras, and the depth error model...
May 24, 2017: Sensors
Xingsong Su, Guotao Duan, Zongke Xu, Fei Zhou, Weiping Cai
The structure and thickness of the chemiresistive thin films can significantly affect their gas sensing performances for the heating-typed sensors. Under light irradiation, however, their influences are still to be addressed. In present paper, the multilayered ZnO porous thin films with different (three types) micro/nanostructures and controllable thickness are fabricated via layer by layer construction of the self-assembled colloidal-layers. The structural and thickness effects of such films on the gas sensing performances to NO2 under ultraviolet (UV) illumination are experimentally studied...
May 10, 2017: Journal of Colloid and Interface Science
V I Francis, E C Stevenson, S L Porter
Pseudomonas aeruginosa is a versatile opportunistic pathogen capable of infecting a broad range of hosts, in addition to thriving in a broad range of environmental conditions outside of hosts. With this versatility comes the need to tightly regulate its genome to optimise its gene expression and behaviour to the prevailing conditions. Two-component systems (TCSs) comprising sensor kinases and response regulators, play a major role in this regulation. This minireview discusses the growing number of two-component systems that have been implicated in the virulence of Pseudomonas aeruginosa, with a special focus on the emerging theme of multikinase networks, which are networks comprising multiple sensor kinases working together, sensing and integrating multiple signals to decide upon the best response...
May 16, 2017: FEMS Microbiology Letters
Heeseok Oh, Jongyoo Kim, Jinwoo Kim, Taewan Kim, Sanghoon Lee, Alan C Bovik
Conventional stereoscopic 3D (S3D) displays do not provide accommodation depth cues of the 3D image or video contents being viewed. The sense of content depths is thus limited to cues supplied by motion parallax (for 3D video), stereoscopic vergence cues created by presenting left and right views to the respective eyes, and other contextual and perspective depth cues. The absence of accommodation cues can induce two kinds of accommodation vergence mismatches (AVM) at the fixation and peripheral points, which can result in severe visual discomfort...
May 9, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
Yue Mei, Sicheng Wang, Xin Shen, Stephen Rabke, Sevan Goenezen
We present a non-destructive approach to sense inclusion objects embedded in a solid medium remotely from force sensors applied to the medium and boundary displacements that could be measured via a digital image correlation system using a set of cameras. We provide a rationale and strategy to uniquely identify the heterogeneous sample composition based on stiffness (here, shear modulus) maps. The feasibility of this inversion scheme is tested with simulated experiments that could have clinical relevance in diagnostic imaging (e...
May 9, 2017: Sensors
Ion Vornicu, Ricardo Carmona-Galán, Ángel Rodríguez-Vázquez
The design of a direct time-of-flight complementary metal-oxide-semiconductor (CMOS) image sensor (dToF-CIS) based on a single-photon avalanche-diode (SPAD) array with an in-pixel time-to-digital converter (TDC) must contemplate system-level aspects that affect its overall performance. This paper provides a detailed analysis of the impact of process parameters, voltage supply, and temperature (PVT) variations on the time bin of the TDC array. Moreover, the design and characterization of a global compensation loop is presented...
May 9, 2017: Sensors
Abdulla Al-Kaff, Fernando García, David Martín, Arturo De La Escalera, José María Armingol
One of the most challenging problems in the domain of autonomous aerial vehicles is the designing of a robust real-time obstacle detection and avoidance system. This problem is complex, especially for the micro and small aerial vehicles, that is due to the Size, Weight and Power (SWaP) constraints. Therefore, using lightweight sensors (i.e., Digital camera) can be the best choice comparing with other sensors; such as laser or radar.For real-time applications, different works are based on stereo cameras in order to obtain a 3D model of the obstacles, or to estimate their depth...
May 7, 2017: Sensors
Vladimir Kopta, John Farserotu, Christian Enz
The Frequency Modulated Ultra-Wideband (FM-UWB) is known as a low-power, low-complexity modulation scheme targeting low to moderate data rates in applications such as wireless body area networks. In this paper, a thorough review of all FM-UWB receivers and transmitters reported in literature is presented. The emphasis is on trends in power reduction that exhibit an improvement by a factor 20 over the past eight years, showing the high potential of FM-UWB. The main architectural and circuit techniques that have led to this improvement are highlighted...
May 6, 2017: Sensors
Tongbin Zhao, Yubao Zhang, Zhenyu Zhang, Zhanhai Li, Shuqi Ma
Backfill mining is an effective option to mitigate ground subsidence, especially for mining under surface infrastructure, such as buildings, dams, rivers and railways. To evaluate its performance, continual long-term field monitoring of the deformation of backfilled gob is important to satisfy strict public scrutiny. Based on industrial Ethernet, a real-time monitoring system was established to monitor the deformation of waste-rock-backfilled gob at -700 m depth in the Tangshan coal mine, Hebei Province, China...
May 5, 2017: Sensors
Xin Jin, Li Liu, Yanqin Chen, Qionghai Dai
This paper derives a mathematical point spread function (PSF) and a depth-invariant focal sweep point spread function (FSPSF) for plenoptic camera 2.0. Derivation of PSF is based on the Fresnel diffraction equation and image formation analysis of a self-built imaging system which is divided into two sub-systems to reflect the relay imaging properties of plenoptic camera 2.0. The variations in PSF, which are caused by changes of object's depth and sensor position variation, are analyzed. A mathematical model of FSPSF is further derived, which is verified to be depth-invariant...
May 1, 2017: Optics Express
M J McPhee, B J Walmsley, B Skinner, B Littler, J P Siddell, L M Cafe, J F Wilkins, V H Oddy, A Alempijevic
The objective of this study was to develop a proof of concept for using off-the-shelf Red Green Blue-Depth (RGB-D) Microsoft Kinect cameras to objectively assess P8 rump fat (P8 fat; mm) and muscle score (MS) traits in Angus cows and steers. Data from low and high muscled cattle (156 cows and 79 steers) were collected at multiple locations and time points. The following steps were required for the 3-dimensional (3D) image data and subsequent machine learning techniques to learn the traits: 1) reduce the high dimensionality of the point cloud data by extracting features from the input signals to produce a compact and representative feature vector, 2) perform global optimization of the signatures using machine learning algorithms and a parallel genetic algorithm, and 3) train a sensor model using regression-supervised learning techniques on the ultrasound P8 fat and the classified learning techniques for the assessed MS for each animal in the data set...
April 2017: Journal of Animal Science
Ni Chen, Zhenbo Ren, Dayan Li, Edmund Y Lam, Guohai Situ
Light field reconstruction from images captured by focal plane sweeping can achieve high lateral resolution comparable to the modern camera sensor. This is impossible for the conventional micro-lenslet-based light field capture systems. However, the severe defocus noise and the low depth resolution limit its applications. In this paper, we analyze the defocus noise in the focal-plane-sweeping-based light field reconstruction technique, and propose a method to reduce the defocus noise. Both numerical and experimental results verify the proposed method...
May 1, 2017: Applied Optics
Zhaoliang Qu, Miao Yu, Yanchao Liu, Baosheng Xu, Rujie He, Yongmao Pei, Hongwei Zhao, Daining Fang
In our study, an elevated-temperature depth-sensing instrumented indentation apparatus was designed and developed to investigate thermo-mechanical response of thermal barrier coatings (TBCs). A furnace was used to heat the test region up to 1600 °C and a heat protection design was proposed to protect electronic devices from high temperature environment. Load was applied by a precise loading motor and a piezoelectric actuator in high (0-440 N) and low (0-40 N) load ranges, respectively. A loading shielding scheme was designed to protect the low load sensor during the high loading process...
April 2017: Review of Scientific Instruments
Karla M Salas-Alcántara, Laura Aparicio-Ixta, Ismael Torres-Gómez, Mario Rodríguez, Gabriel Ramos-Ortiz, Rafael Espinosa-Luna, Juan L Pichardo-Molina
A modal interferometer by a single mechanically induced long-period fiber grating (MI-LPFG) using a half-length coating fiber is presented. The coating material used for this Letter is a film of silica nanoparticles doped with an organic chromophore. The silica nanoparticles, with diameters within the range of 40-50 nm, were deposited over 3.5 cm length of fiber by the dip-coating method, forming a film with a thickness between 500 and 1250 nm. Then the modal interferometer was implemented by inscribing the MI-LPFG over the coated fiber section and a similar fiber length of the uncoated fiber...
May 1, 2017: Optics Letters
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
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...
September 15, 2017: Biosensors & Bioelectronics
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
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
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