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Depth sensor

Pablo A Coelho, Jorge E Tapia, Francisco Pérez, Sergio N Torres, Carlos Saavedra
Digital photonic sensors have greatly evolved to maximize sensitivity and spatial, spectral, and temporal imaging resolution. For low-energy photons, new designs have generated new types of noise that degrade the formed-image signal-to-noise ratio to values lower than 1. Fixed-pattern noise (FPN), which is produced by the non-uniform focal-plane-array optoelectronics response, is an ill-posed problem in infrared and hyperspectral imaging science. Here, we experimentally show that the FPN behaves as an object at a depth of infinity when a light field is captured by an imaging system...
October 12, 2017: Scientific Reports
Ruhul Amin, Benjamin L Richards, William F X E Misa, Jeremy C Taylor, Dianna R Miller, Audrey K Rollo, Christopher Demarke, Hanumant Singh, Grace C Young, Jeremy Childress, Justin E Ossolinski, Russell T Reardon, Kyle H Koyanagi
The Pacific Islands Fisheries Science Center deploys the Modular Optical Underwater Survey System (MOUSS) to estimate the species-specific, size-structured abundance of commercially-important fish species in Hawaii and the Pacific Islands. The MOUSS is an autonomous stereo-video camera system designed for the in situ visual sampling of fish assemblages. This system is rated to 500 m and its low-light, stereo-video cameras enable identification, counting, and sizing of individuals at a range of 0.5-10 m. The modular nature of MOUSS allows for the efficient and cost-effective use of various imaging sensors, power systems, and deployment platforms...
October 11, 2017: Sensors
Daphne Geerse, Bert Coolen, Detmar Kolijn, Melvyn Roerdink
The Kinect v2 sensor may be a cheap and easy to use sensor to quantify gait in clinical settings, especially when applied in set-ups integrating multiple Kinect sensors to increase the measurement volume. Reliable estimates of foot placement locations are required to quantify spatial gait parameters. This study aimed to systematically evaluate the effects of distance from the sensor, side and step length on estimates of foot placement locations based on Kinect's ankle body points. Subjects (n = 12) performed stepping trials at imposed foot placement locations distanced 2 m or 3 m from the Kinect sensor (distance), for left and right foot placement locations (side), and for five imposed step lengths...
October 10, 2017: Sensors
Kyung-Hoon Song, Jaehuk Choi, Jung-Hoon Chun
In this paper, we describe a method for improving the quality of fingerprint images at long sensing distances by reducing the fringe capacitance formed between a pixel and surrounding fingerprint patterns. Air-walls were applied to the glass attached to a fingerprint sensor for reducing the edge capacitance. Fingerprints and air-wall structures were modeled using a three-dimensional capacitance analysis tool. A prototype was fabricated by stacking glass layers with air-walls with a depth of 50 μm and a pitch of 50 μm on a silicon-type capacitive sensor...
October 7, 2017: Sensors
Raphael Falque, Teresa Vidal-Calleja, Jaime Valls Miro
Remote-Field Eddy-Current (RFEC) technology is often used as a Non-Destructive Evaluation (NDE) method to prevent water pipe failures. By analyzing the RFEC data, it is possible to quantify the corrosion present in pipes. Quantifying the corrosion involves detecting defects and extracting their depth and shape. For large sections of pipelines, this can be extremely time-consuming if performed manually. Automated approaches are therefore well motivated. In this article, we propose an automated framework to locate and segment defects in individual pipe segments, starting from raw RFEC measurements taken over large pipelines...
October 6, 2017: Sensors
David M Broday
The evaluation of the effects of air pollution on public health and human-wellbeing requires reliable data. Standard air quality monitoring stations provide accurate measurements of airborne pollutant levels, but, due to their sparse distribution, they cannot capture accurately the spatial variability of air pollutant concentrations within cities. Dedicated in-depth field campaigns have dense spatial coverage of the measurements but are held for relatively short time periods. Hence, their representativeness is limited...
October 2, 2017: Sensors
Giacomo Giorli, Whitlow W L Au
Sperm whales forage in the deep ocean, hunting for squid. An innovative approach for the study of sperm whale foraging behavior and habitat selection is reported in this letter. A DIDSON imaging sonar mounted on a profiler with a conductivity, temperature, and depth sensor was used to count and measure potential prey in the deep ocean during sperm whales' acoustical foraging encounters in Hawaii. Preliminary results show how this technique can be applied to the study of deep diving whale foraging and habitat selection...
September 2017: Journal of the Acoustical Society of America
Joseph Bailey, Nicholas Long, Arvid Hunze
This work investigates an eddy current-based non-destructive testing (NDT) method to characterize corrosion of pipes under thermal insulation, one of the leading failure mechanisms for insulated pipe infrastructure. Artificial defects were machined into the pipe surface to simulate the effect of corrosion wall loss. We show that by using a giant magnetoresistance (GMR) sensor array and a high current (300 A), single sinusoidal low frequency (5-200 Hz) pipe-encircling excitation scheme it is possible to quantify wall loss defects without removing the insulation or weather shield...
September 28, 2017: Sensors
Safdar Hussain Bouk, Syed Hassan Ahmed, Kyung-Joon Park, Yongsoon Eun
Underwater Acoustic Sensor Network (UASN) comes with intrinsic constraints because it is deployed in the aquatic environment and uses the acoustic signals to communicate. The examples of those constraints are long propagation delay, very limited bandwidth, high energy cost for transmission, very high signal attenuation, costly deployment and battery replacement, and so forth. Therefore, the routing schemes for UASN must take into account those characteristics to achieve energy fairness, avoid energy holes, and improve the network lifetime...
September 26, 2017: Sensors
Ashley C Whiteman, Hendrik Santosa, Daniel F Chen, Susan Perlman, Theodore Huppert
Functional near-infrared spectroscopy (fNIRS) is a noninvasive brain imaging technique that uses scalp-placed light sensors to measure evoked changes in cerebral blood oxygenation. The portability, low overhead cost, and ability to use this technology under a wide range of experimental environments make fNIRS well-suited for studies involving infants and children. However, since fNIRS does not directly provide anatomical or structural information, these measurements may be sensitive to individual or group level differences associated with variations in head size, depth of the brain from the scalp, or other anatomical factors affecting the penetration of light into the head...
January 2018: Neurophotonics
Waqas Rehan, Stefan Fischer, Maaz Rehan
A large number of routing-related surveys are published so far for Wireless Sensor Networks (WSNs) that exhibit either complete or partial emphasis on routing in WSNs. These surveys classify and discuss the relevant routing protocols published mainly in the fields of classical, energy efficient, secure, hierarchical, geographic, intelligent, Quality of Service (QoS)-based and multipath WSNs. However, to the best of our knowledge, no study is presented so far which may clearly categorize the routing-related survey literature for WSNs...
July 26, 2017: Sensors
Jen-Chun Wang, Shih-Hung Tsai, Ying-Hsin Chen, Yu-Long Chen, Shi-Jye Chu, Wen-I Liao
BACKGROUND: Chest compression (CC) quality is associated with rescuer posture and body weight. We designed a Kinect module-based real-time audiovisual feedback (AVF) device to investigate the relationship between rescuer posture, body weight, and CC quality. METHODS: A total of 100 healthcare professionals were enrolled as participants in this randomized trial. A Kinect-based sensor system was used to monitor the depth and rate of CC and provide further real-time feedback...
September 15, 2017: American Journal of Emergency Medicine
Shangquan Wu, Zhiguo Zhang, Xiarong Zhou, Hong Liu, Changguo Xue, Gang Zhao, Yunxia Cao, Qingchuan Zhang, Xiaoping Wu
Infertility, whether of male or female origin, is a critical challenge facing the low birth rate and aging population throughout the world, and semen analysis is a cornerstone of the diagnostic evaluation of the male contribution to infertility. This means that tools which can characterize sperm properties in an effective manner are very much needed. The conventional approaches are essentially image-based, which have a limited value for analyzing sperm properties. Here, we show that an assay using nanomechanical sensors can detect sperm motility based on nanomotion...
September 11, 2017: Nanoscale
I Schifter, G Sánchez-Reyna, C González-Macías, L Salazar-Coria, C González-Lozano
Vertical profiles of deep-water fluorescence determined by the chlorophyll sensor, polycyclic aromatic hydrocarbons, biomarkers, and other miscellaneous parameters measured in the southern Gulf of Mexico are reported. In the course of the survey, unexpected deep fluorescences were recorded (>1100m depth) in half of the 40 stations studied, a novel finding in this area of the Gulf. Currently, the deep-water fluorescence phenomenon is not completely understood, however we observe linear correlation between the fluorescence intensity and chlorophyll-α concentrations and coincidence of higher number of hydrocarbonoclastic bacteria in samples collected precisely in the deep-water fluorescence...
September 7, 2017: Marine Pollution Bulletin
Mingliang Jiang, Mouchao Lv, Zhong Deng, Guoliang Zhai
In a variety of agricultural activities, such as irrigation scheduling and nutrient management, soil water content is regarded as an essential parameter. Either power supply or long-distance cable is hardly available within field scale. For the necessity of monitoring soil water dynamics at field scale, this study presents a wireless soil moisture sensor based on the impedance transform of the frequency domain. The sensor system is powered by solar energy, and the data can be instantly transmitted by wireless communication...
2017: PloS One
Wei Wang, Zengxin Pan, Feiyue Mao, Wei Gong, Longjiao Shen
The Visible Infrared Imaging Radiometer Suite (VIIRS) is a next-generation polar-orbiting operational environmental sensor with a capability for global aerosol observations. Identifying land aerosol types is important because aerosol types are a basic input in retrieving aerosol optical properties for VIIRS. The VIIRS algorithm can automatically select the optimal land aerosol model by minimizing the residual between the derived and expected spectral surface reflectance. In this study, these selected VIIRS aerosol types are evaluated using collocated aerosol types obtained from the Aerosol Robotic Network (AERONET) level 1...
September 5, 2017: International Journal of Environmental Research and Public Health
Charanjit Kaur, Gurugirijha Rathnasamy, Eng-Ang Ling
Microglia exist in different morphological forms in the developing brain. They show a small cell body with scanty cytoplasm with many branching processes in the grey matter of the developing brain. However, in the white matter such as the corpus callosum where the unmyelinated axons are loosely organized, they appear in an amoeboid form having a round cell body endowed with copious cytoplasm rich in organelles. The amoeboid cells eventually transform into ramified microglia in the second postnatal week when the tissue becomes more compact with the onset of myelination...
September 1, 2017: Journal of Neuropathology and Experimental Neurology
Byung Gyu Yu, Je Hyeok Oh, Yeomyung Kim, Tae Wook Kim
OBJECTIVE: We developed a new chest compression depth (CCD) measuring technology using radar and impulse-radio ultra-wideband (IR-UWB) sensor. This study was performed to determine its accuracy on a soft surface. METHODS: Four trials, trial 1: chest compressions on the floor using an accelerometer device; trial 2: chest compressions on the floor using an IR-UWB sensor; trial 3: chest compressions on a foam mattress using an accelerometer device; trial 4: chest compressions on a foam mattress using an IR-UWB sensor, were performed in a random order...
2017: PloS One
M R Palomo-Marín, F Rueda-Holgado, J Marín-Expósito, E Pinilla-Gil
We report here the use of commercial screen-printed disposable sensors comprising a sputtered bismuth working electrode, a silver pseudo reference electrode and a carbon auxiliary electrode (whole set referred as BispSPE), as a new and advantageous alternative for reliable and convenient monitoring of Cd and Pb in atmospheric particulate matter (PM10 fraction) by anodic stripping voltammetry after acid digestion. After a detailed exploration of surface composition and depth profiles of the BispSPE by SEM, EDX, XPS and EIS, chemical and instrumental variables have been optimized to develop a reliable method capable of measuring Cd and Pb with detection limits of 11...
December 1, 2017: Talanta
Yiming Yan, Zhichao Tan, Nan Su, Chunhui Zhao
In this paper, a building extraction method is proposed based on a stacked sparse autoencoder with an optimized structure and training samples. Building extraction plays an important role in urban construction and planning. However, some negative effects will reduce the accuracy of extraction, such as exceeding resolution, bad correction and terrain influence. Data collected by multiple sensors, as light detection and ranging (LIDAR), optical sensor etc., are used to improve the extraction. Using digital surface model (DSM) obtained from LIDAR data and optical images, traditional method can improve the extraction effect to a certain extent, but there are some defects in feature extraction...
August 24, 2017: Sensors
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