WorldWideScience

Sample records for include active sensors

  1. Active and Passive Hybrid Sensor

    Science.gov (United States)

    Carswell, James R.

    2010-01-01

    A hybrid ocean wind sensor (HOWS) can map ocean vector wind in low to hurricane-level winds, and non-precipitating and precipitating conditions. It can acquire active and passive measurements through a single aperture at two wavelengths, two polarizations, and multiple incidence angles. Its low profile, compact geometry, and low power consumption permits installation on air craft platforms, including high-altitude unmanned aerial vehicles (UAVs).

  2. Radiation-activated sensor

    International Nuclear Information System (INIS)

    Nirschl, J.C.

    1976-01-01

    A sensing system is described for use in a remote location which detects electromagnetic radiation energy, the system being self-activating, turning itself automatically on and off, as a function of radiation intensity across the detector. In essence, when no radiation is present across the detector, the system will consume no power, the switches and MOSFET discriminator being essentially in an ''off'' position. Radiation across the detector provides a current to an input capacitance which when charged turns on the switch and the MOSFET discriminator. A switch driver produces an output pulse showing the presence of radiation; the system then shuts off awaiting the next radiation input. Since the sensor system uses virtually no power unless radiation is present, it is ideally suited for use in remote environments where battery power and size is a predominant consideration. 2 claims, 3 drawing figures

  3. Zebrafish homologs of genes within 16p11.2, a genomic region associated with brain disorders, are active during brain development, and include two deletion dosage sensor genes

    Directory of Open Access Journals (Sweden)

    Alicia Blaker-Lee

    2012-11-01

    Deletion or duplication of one copy of the human 16p11.2 interval is tightly associated with impaired brain function, including autism spectrum disorders (ASDs, intellectual disability disorder (IDD and other phenotypes, indicating the importance of gene dosage in this copy number variant region (CNV. The core of this CNV includes 25 genes; however, the number of genes that contribute to these phenotypes is not known. Furthermore, genes whose functional levels change with deletion or duplication (termed ‘dosage sensors’, which can associate the CNV with pathologies, have not been identified in this region. Using the zebrafish as a tool, a set of 16p11.2 homologs was identified, primarily on chromosomes 3 and 12. Use of 11 phenotypic assays, spanning the first 5 days of development, demonstrated that this set of genes is highly active, such that 21 out of the 22 homologs tested showed loss-of-function phenotypes. Most genes in this region were required for nervous system development – impacting brain morphology, eye development, axonal density or organization, and motor response. In general, human genes were able to substitute for the fish homolog, demonstrating orthology and suggesting conserved molecular pathways. In a screen for 16p11.2 genes whose function is sensitive to hemizygosity, the aldolase a (aldoaa and kinesin family member 22 (kif22 genes were identified as giving clear phenotypes when RNA levels were reduced by ∼50%, suggesting that these genes are deletion dosage sensors. This study leads to two major findings. The first is that the 16p11.2 region comprises a highly active set of genes, which could present a large genetic target and might explain why multiple brain function, and other, phenotypes are associated with this interval. The second major finding is that there are (at least two genes with deletion dosage sensor properties among the 16p11.2 set, and these could link this CNV to brain disorders such as ASD and IDD.

  4. Activity Recognition Invariant to Sensor Orientation with Wearable Motion Sensors.

    Science.gov (United States)

    Yurtman, Aras; Barshan, Billur

    2017-08-09

    Most activity recognition studies that employ wearable sensors assume that the sensors are attached at pre-determined positions and orientations that do not change over time. Since this is not the case in practice, it is of interest to develop wearable systems that operate invariantly to sensor position and orientation. We focus on invariance to sensor orientation and develop two alternative transformations to remove the effect of absolute sensor orientation from the raw sensor data. We test the proposed methodology in activity recognition with four state-of-the-art classifiers using five publicly available datasets containing various types of human activities acquired by different sensor configurations. While the ordinary activity recognition system cannot handle incorrectly oriented sensors, the proposed transformations allow the sensors to be worn at any orientation at a given position on the body, and achieve nearly the same activity recognition performance as the ordinary system for which the sensor units are not rotatable. The proposed techniques can be applied to existing wearable systems without much effort, by simply transforming the time-domain sensor data at the pre-processing stage.

  5. Resource Discovery in Activity-Based Sensor Networks

    DEFF Research Database (Denmark)

    Bucur, Doina; Bardram, Jakob

    This paper proposes a service discovery protocol for sensor networks that is specifically tailored for use in humancentered pervasive environments. It uses the high-level concept of computational activities (as logical bundles of data and resources) to give sensors in Activity-Based Sensor Networks...... (ABSNs) knowledge about their usage even at the network layer. ABSN redesigns classical network-level service discovery protocols to include and use this logical structuring of the network for a more practically applicable service discovery scheme. Noting that in practical settings activity-based sensor...

  6. Using Sensors to Study Home Activities

    Directory of Open Access Journals (Sweden)

    Jie Jiang

    2017-12-01

    Full Text Available Understanding home activities is important in social research to study aspects of home life, e.g., energy-related practices and assisted living arrangements. Common approaches to identifying which activities are being carried out in the home rely on self-reporting, either retrospectively (e.g., interviews, questionnaires, and surveys or at the time of the activity (e.g., time use diaries. The use of digital sensors may provide an alternative means of observing activities in the home. For example, temperature, humidity and light sensors can report on the physical environment where activities occur, while energy monitors can report information on the electrical devices that are used to assist the activities. One may then be able to infer from the sensor data which activities are taking place. However, it is first necessary to calibrate the sensor data by matching it to activities identified from self-reports. The calibration involves identifying the features in the sensor data that correlate best with the self-reported activities. This in turn requires a good measure of the agreement between the activities detected from sensor-generated data and those recorded in self-reported data. To illustrate how this can be done, we conducted a trial in three single-occupancy households from which we collected data from a suite of sensors and from time use diaries completed by the occupants. For sensor-based activity recognition, we demonstrate the application of Hidden Markov Models with features extracted from mean-shift clustering and change points analysis. A correlation-based feature selection is also applied to reduce the computational cost. A method based on Levenshtein distance for measuring the agreement between the activities detected in the sensor data and that reported by the participants is demonstrated. We then discuss how the features derived from sensor data can be used in activity recognition and how they relate to activities recorded in time

  7. Efficient sensor selection for active information fusion.

    Science.gov (United States)

    Zhang, Yongmian; Ji, Qiang

    2010-06-01

    In our previous paper, we formalized an active information fusion framework based on dynamic Bayesian networks to provide active information fusion. This paper focuses on a central issue of active information fusion, i.e., the efficient identification of a subset of sensors that are most decision relevant and cost effective. Determining the most informative and cost-effective sensors requires an evaluation of all the possible subsets of sensors, which is computationally intractable, particularly when information-theoretic criterion such as mutual information is used. To overcome this challenge, we propose a new quantitative measure for sensor synergy based on which a sensor synergy graph is constructed. Using the sensor synergy graph, we first introduce an alternative measure to multisensor mutual information for characterizing the sensor information gain. We then propose an approximated nonmyopic sensor selection method that can efficiently and near-optimally select a subset of sensors for active fusion. The simulation study demonstrates both the performance and the efficiency of the proposed sensor selection method.

  8. Sensor Development for Active Flow Control

    Science.gov (United States)

    Kahng, Seun K.; Gorton, Susan A.; Mau, Johnney C.; Soto, Hector L.; Hernandez, Corey D.

    2001-01-01

    Presented are the developmental efforts for MEMS sensors for a closed-loop active flow control in a low-speed wind tunnel evaluation. The MEMS sensors are designed in-house and fabricated out of house, and the shear sensors are a thermal type that are collocated with temperature and pressure sensors on a flexible polyimide sheet, which conforms to surfaces of a simple curvature. A total of 6 sensors are located within a 1.5 by 3 mm area as a cluster with each sensor being 300 pm square. The thickness of this sensor cluster is 75 pm. Outputs from the shear sensors have been compared with respect to those of the Preston tube for evaluation of the sensors on a flat plate. Pressure sensors are the absolute type and have recorded pressure measurements within 0.05 percent of the tunnel ESP pressure sensor readings. The sensors and signal conditioning electronics have been tested on both a flat plate and a ramp in Langley s 15-Inch Low-Turbulence Tunnel. The system configuration and control PC is configured with LabView, where calibration constants are stored for desired compensation and correction. The preliminary test results are presented within.

  9. Active Sensor Configuration Validation for Refrigeration Systems

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Blanke, Mogens; Niemann, Hans Henrik

    2010-01-01

    -diagnosis methods falling short on this problem, this paper suggests an active diagnosis procedure to isolate sensor faults at the commissioning stage, before normal operation has started. Using statistical methods, residuals are evaluated versus multiple hypothesis models in a minimization process to uniquely......Major faults in the commissioning phase of refrigeration systems are caused by defects related to sensors. With a number of similar sensors available that do not differ by type but only by spatial location in the plant, interchange of sensors is a common defect. With sensors being used quite...... differently by the control system, fault-finding is difficult in practice and defects are regularly causing commissioning delays at considerable expense. Validation and handling of faults in the sensor configuration are therefore essential to cut costs during commissioning. With passive fault...

  10. Development of smart active layer sensor

    International Nuclear Information System (INIS)

    Lee, Young Sup; Lee, Sang Il; Yoon, Dong Jin; Kwon, Jae Hwa

    2004-01-01

    Structural health monitoring (SHM) is a new technology that will be increasingly applied at the industrial field as a potential approach to improve cost and convenience of structural inspection. Recently, the development of smart sensor is very active for real application. This study has focused on preparation and application study of SAL sensor. In order to detect elastic wave, smart piezoelectric sensor, SAL, is fabricated by using a piezoelectric element, shielding layer and protection layer. This protection layer plays an important role in a patched network of distributed piezoelectric sensor and shielding treatment. Four types of SAL sensor are designed/prepared/tested, and these details will be discussed in the paper. In this study, SAL sensor can be feasibly applied to perform structural health monitoring and to detect damage sources which result in elastic waves.

  11. Resource Discovery in Activity-Based Sensor Networks

    DEFF Research Database (Denmark)

    Bucur, Doina; Bardram, Jakob

    This paper proposes a service discovery protocol for sensor networks that is specifically tailored for use in humancentered pervasive environments. It uses the high-level concept of computational activities (as logical bundles of data and resources) to give sensors in Activity-Based Sensor Networ....... ABSN enhances the generic Extended Zone Routing Protocol with logical sensor grouping and greatly lowers network overhead during the process of discovery, while keeping discovery latency close to optimal.......This paper proposes a service discovery protocol for sensor networks that is specifically tailored for use in humancentered pervasive environments. It uses the high-level concept of computational activities (as logical bundles of data and resources) to give sensors in Activity-Based Sensor Networks...... (ABSNs) knowledge about their usage even at the network layer. ABSN redesigns classical network-level service discovery protocols to include and use this logical structuring of the network for a more practically applicable service discovery scheme. Noting that in practical settings activity-based sensor...

  12. Active node determination for correlated data gathering in wireless sensor networks

    OpenAIRE

    Karasabun, Efe

    2009-01-01

    Ankara : The Department of Computer Engineering and the Institute of Engineering and Science of Bilkent University, 2009. Thesis (Master's) -- Bilkent University, 2009. Includes bibliographical references leaves 53-55. In wireless sensor network applications where data gathered by different sensor nodes is correlated, not all sensor nodes need to be active for the wireless sensor network to be functional. However, the sensor nodes that are selected as active should form a co...

  13. Integrated active sensor system for real time vibration monitoring.

    Science.gov (United States)

    Liang, Qijie; Yan, Xiaoqin; Liao, Xinqin; Cao, Shiyao; Lu, Shengnan; Zheng, Xin; Zhang, Yue

    2015-11-05

    We report a self-powered, lightweight and cost-effective active sensor system for vibration monitoring with multiplexed operation based on contact electrification between sensor and detected objects. The as-fabricated sensor matrix is capable of monitoring and mapping the vibration state of large amounts of units. The monitoring contents include: on-off state, vibration frequency and vibration amplitude of each unit. The active sensor system delivers a detection range of 0-60 Hz, high accuracy (relative error below 0.42%), long-term stability (10000 cycles). On the time dimension, the sensor can provide the vibration process memory by recording the outputs of the sensor system in an extend period of time. Besides, the developed sensor system can realize detection under contact mode and non-contact mode. Its high performance is not sensitive to the shape or the conductivity of the detected object. With these features, the active sensor system has great potential in automatic control, remote operation, surveillance and security systems.

  14. Physical Activity Recognition from Smartphone Embedded Sensors

    DEFF Research Database (Denmark)

    Prudêncio, João; Aguiar, Ana; Roetter, Daniel Enrique Lucani

    2013-01-01

    The ubiquity of smartphones has motivated efforts to use the embedded sensors to detect various aspects of user context to transparently provide personalized and contextualized services to the user. One relevant piece of context is the physical activity of the smartphone user. In this paper, we...... propose a novel set of features for distinguishing five physical activities using only sensors embedded in the smartphone. Specifically, we introduce features that are normalized using the orientation sensor such that horizontal and vertical movements are explicitly computed. We evaluate a neural network...... classifier in experiments in the wild with multiple users and hardware, we achieve accuracies above 90% for a single user and phone, and above 65% for multiple users, which is higher that similar works on the same set of activities, demonstrating the potential of our approach....

  15. Performance of active edge pixel sensors

    Science.gov (United States)

    Bomben, M.; Ducourthial, A.; Bagolini, A.; Boscardin, M.; Bosisio, L.; Calderini, G.; D'Eramo, L.; Giacomini, G.; Marchiori, G.; Zorzi, N.; Rummler, A.; Weingarten, J.

    2017-05-01

    To cope with the High Luminosity LHC harsh conditions, the ATLAS inner tracker has to be upgraded to meet requirements in terms of radiation hardness, pile up and geometrical acceptance. The active edge technology allows to reduce the insensitive area at the border of the sensor thanks to an ion etched trench which avoids the crystal damage produced by the standard mechanical dicing process. Thin planar n-on-p pixel sensors with active edge have been designed and produced by LPNHE and FBK foundry. Two detector module prototypes, consisting of pixel sensors connected to FE-I4B readout chips, have been tested with beams at CERN and DESY. In this paper the performance of these modules are reported. In particular the lateral extension of the detection volume, beyond the pixel region, is investigated and the results show high hit efficiency also at the detector edge, even in presence of guard rings.

  16. JPL CMOS Active Pixel Sensor Technology

    Science.gov (United States)

    Fossum, E. R.

    1995-01-01

    This paper will present the JPL-developed complementary metal- oxide-semiconductor (CMOS) active pixel sensor (APS) technology. The CMOS APS has achieved performance comparable to charge coupled devices, yet features ultra low power operation, random access readout, on-chip timing and control, and on-chip analog to digital conversion. Previously published open literature will be reviewed.

  17. Development of SERS active fibre sensors

    International Nuclear Information System (INIS)

    Polwart, Ewan

    2002-01-01

    Surface-enhanced Raman scattering (SERS) is sensitive and selective and when coupled with fibre-optics could potentially produce an effective chemical sensing system. This thesis concerns the development of a single-fibre-based sensor, with an integral SERS-active substrate. A number of different methods for the manufacture of SERS-active surfaces on glass substrates were investigated and compared. The immobilisation of metal nanoparticles on glass functionalised with (3-aminopropyl)trimethoxysilane emerged as a suitable approach for the production of sensors. Substrates prepared by this approach were characterised using UV-visible spectroscopy, electron microscopy and Raman mapping. It was found that exposure of substrates to laser radiation led to a decrease in the signal recorded from adsorbed analytes. This speed of the decrease was shown to depend on the analyte, and the exciting wavelength and power. SERS-active fibre sensors were produced by immobilisation of silver nanoparticles at the distal end of a (3-aminopropyl)trimethoxysilane-derivatised optical fibre. These sensors were used to obtain spectra with good signal to noise ratios from 4-(benzotriazol-5-ylazo)-3,5-dimethoxyphenylamine and crystal violet. Sensing of dyes in effluent was also investigated. The development of sensors for the measurement of pH, by treating the SERS-active fibre tip with pH sensitive dyes is also described. Spectral changes were observed with these sensors as a response to the pH. Partial least squares regression was used to produce linear calibration models for the pH range 5-11 from which it was possible to predict the pH with an accuracy of ∼0.2 pH units. Some of the limitations of these sensors were explored. The feasibility of using these sensors for measurement of oxygen and thiols, was investigated. The measurement of oxygen using methylene blue as a transducer was demonstrated. Two transduction methodologies--reactions with iron porphyrins and pyrrole-2,5-diones

  18. Radiation effects on active pixel sensors (APS)

    International Nuclear Information System (INIS)

    Cohen, M.; David, J.P.

    1999-01-01

    Active pixel sensor (APS) is a new generation of image sensors which presents several advantages relatively to charge coupled devices (CCDs) particularly for space applications (APS requires only 1 voltage to operate which reduces considerably current consumption). Irradiation was performed using 60 Co gamma radiation at room temperature and at a dose rate of 150 Gy(Si)/h. 2 types of APS have been tested: photodiode-APS and photoMOS-APS. The results show that photoMOS-APS is more sensitive to radiation effects than photodiode-APS. Important parameters of image sensors like dark currents increase sharply with dose levels. Nevertheless photodiode-APS sensitivity is one hundred time lower than photoMOS-APS sensitivity

  19. Functionalized active-nucleus complex sensor

    Science.gov (United States)

    Pines, Alexander; Wemmer, David E.; Spence, Megan; Rubin, Seth

    2003-11-25

    A functionalized active-nucleus complex sensor that selectively associates with one or more target species, and a method for assaying and screening for one or a plurality of target species utilizing one or a plurality of functionalized active-nucleus complexes with at least two of the functionalized active-nucleus complexes having an attraction affinity to different corresponding target species. The functionalized active-nucleus complex has an active-nucleus and a targeting carrier. The method involves functionalizing an active-nucleus, for each functionalized active-nucleus complex, by incorporating the active-nucleus into a macromolucular or molecular complex that is capable of binding one of the target species and then bringing the macromolecular or molecular complexes into contact with the target species and detecting the occurrence of or change in a nuclear magnetic resonance signal from each of the active-nuclei in each of the functionalized active-nucleus complexes.

  20. Monitoring system including an electronic sensor platform and an interrogation transceiver

    Science.gov (United States)

    Kinzel, Robert L.; Sheets, Larry R.

    2003-09-23

    A wireless monitoring system suitable for a wide range of remote data collection applications. The system includes at least one Electronic Sensor Platform (ESP), an Interrogator Transceiver (IT) and a general purpose host computer. The ESP functions as a remote data collector from a number of digital and analog sensors located therein. The host computer provides for data logging, testing, demonstration, installation checkout, and troubleshooting of the system. The IT transmits signals from one or more ESP's to the host computer to the ESP's. The IT host computer may be powered by a common power supply, and each ESP is individually powered by a battery. This monitoring system has an extremely low power consumption which allows remote operation of the ESP for long periods; provides authenticated message traffic over a wireless network; utilizes state-of-health and tamper sensors to ensure that the ESP is secure and undamaged; has robust housing of the ESP suitable for use in radiation environments; and is low in cost. With one base station (host computer and interrogator transceiver), multiple ESP's may be controlled at a single monitoring site.

  1. Paper-Based Active Tactile Sensor Array.

    Science.gov (United States)

    Zhong, Qize; Zhong, Junwen; Cheng, Xiaofeng; Yao, Xu; Wang, Bo; Li, Wenbo; Wu, Nan; Liu, Kang; Hu, Bin; Zhou, Jun

    2015-11-25

    A paper-based active tactile sensor -array (PATSA) with a dynamic sensitivity of 0.35 V N(-1) is demonstrated. The pixel position of the PATSA can be routed by analyzing the real-time recording voltages in the pressing process. The PATSA performance, which remains functional when removing partial areas, reveals that the device has a potential application to customized electronic skins. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Physical Human Activity Recognition Using Wearable Sensors.

    Science.gov (United States)

    Attal, Ferhat; Mohammed, Samer; Dedabrishvili, Mariam; Chamroukhi, Faicel; Oukhellou, Latifa; Amirat, Yacine

    2015-12-11

    This paper presents a review of different classification techniques used to recognize human activities from wearable inertial sensor data. Three inertial sensor units were used in this study and were worn by healthy subjects at key points of upper/lower body limbs (chest, right thigh and left ankle). Three main steps describe the activity recognition process: sensors' placement, data pre-processing and data classification. Four supervised classification techniques namely, k-Nearest Neighbor (k-NN), Support Vector Machines (SVM), Gaussian Mixture Models (GMM), and Random Forest (RF) as well as three unsupervised classification techniques namely, k-Means, Gaussian mixture models (GMM) and Hidden Markov Model (HMM), are compared in terms of correct classification rate, F-measure, recall, precision, and specificity. Raw data and extracted features are used separately as inputs of each classifier. The feature selection is performed using a wrapper approach based on the RF algorithm. Based on our experiments, the results obtained show that the k-NN classifier provides the best performance compared to other supervised classification algorithms, whereas the HMM classifier is the one that gives the best results among unsupervised classification algorithms. This comparison highlights which approach gives better performance in both supervised and unsupervised contexts. It should be noted that the obtained results are limited to the context of this study, which concerns the classification of the main daily living human activities using three wearable accelerometers placed at the chest, right shank and left ankle of the subject.

  3. Sensors

    CERN Document Server

    Pigorsch, Enrico

    1997-01-01

    This is the 5th edition of the Metra Martech Directory "EUROPEAN CENTRES OF EXPERTISE - SENSORS." The entries represent a survey of European sensors development. The new edition contains 425 detailed profiles of companies and research institutions in 22 countries. This is reflected in the diversity of sensors development programmes described, from sensors for physical parameters to biosensors and intelligent sensor systems. We do not claim that all European organisations developing sensors are included, but this is a good cross section from an invited list of participants. If you see gaps or omissions, or would like your organisation to be included, please send details. The data base invites the formation of effective joint ventures by identifying and providing access to specific areas in which organisations offer collaboration. This issue is recognised to be of great importance and most entrants include details of collaboration offered and sought. We hope the directory on Sensors will help you to find the ri...

  4. Hybrid active pixel sensors in infrared astronomy

    International Nuclear Information System (INIS)

    Finger, Gert; Dorn, Reinhold J.; Meyer, Manfred; Mehrgan, Leander; Stegmeier, Joerg; Moorwood, Alan

    2005-01-01

    Infrared astronomy is currently benefiting from three main technologies providing high-performance hybrid active pixel sensors. In the near infrared from 1 to 5 μm two technologies, both aiming for buttable 2Kx2K mosaics, are competing, namely InSb and HgCdTe grown by LPE or MBE on Al 2 O 3 , Si or CdZnTe substrates. Blocked impurity band Si:As arrays cover the mid infrared spectral range from 8 to 28 μm. Adaptive optics combined with multiple integral field units feeding high-resolution spectrographs drive the requirements for the array format of infrared sensors used at ground-based infrared observatories. The pixel performance is now approaching fundamental limits. In view of this development, a detection limit for the photon flux of the ideal detector will be derived, depending only on the temperature and the impedance of the detector. It will be shown that this limit is approximated by state of the art infrared arrays for long on-chip integrations. Different detector materials are compared and strategies to populate large focal planes are discussed. The need for the development of small-format low noise sensors for adaptive optics and interferometry will be pointed out

  5. Electro-active sensor, method for constructing the same; apparatus and circuitry for detection of electro-active species

    Science.gov (United States)

    Buehler, Martin (Inventor)

    2009-01-01

    An electro-active sensor includes a nonconductive platform with a first electrode set attached with a first side of a nonconductive platform. The first electrode set serves as an electrochemical cell that may be utilized to detect electro-active species in solution. A plurality of electrode sets and a variety of additional electrochemical cells and sensors may be attached with the nonconductive platform. The present invention also includes a method for constructing the aforementioned electro-active sensor. Additionally, an apparatus for detection and observation is disclosed, where the apparatus includes a sealable chamber for insertion of a portion of an electro-active sensor. The apparatus allows for monitoring and detection activities. Allowing for control of attached cells and sensors, a dual-mode circuitry is also disclosed. The dual-mode circuitry includes a switch, allowing the circuitry to be switched from a potentiostat to a galvanostat mode.

  6. A sensor and video based ontology for activity recognition in smart environments.

    Science.gov (United States)

    Mitchell, D; Morrow, Philip J; Nugent, Chris D

    2014-01-01

    Activity recognition is used in a wide range of applications including healthcare and security. In a smart environment activity recognition can be used to monitor and support the activities of a user. There have been a range of methods used in activity recognition including sensor-based approaches, vision-based approaches and ontological approaches. This paper presents a novel approach to activity recognition in a smart home environment which combines sensor and video data through an ontological framework. The ontology describes the relationships and interactions between activities, the user, objects, sensors and video data.

  7. Wearable sensor glove based on conducting fabric using electrodermal activity and pulse-wave sensors for e-health application.

    Science.gov (United States)

    Lee, Youngbum; Lee, Byungwoo; Lee, Myoungho

    2010-03-01

    Improvement of the quality and efficiency of health in medicine, both at home and the hospital, calls for improved sensors that might be included in a common carrier such as a wearable sensor device to measure various biosignals and provide healthcare services that use e-health technology. Designed to be user-friendly, smart clothes and gloves respond well to the end users for health monitoring. This study describes a wearable sensor glove that is equipped with an electrodermal activity (EDA) sensor, pulse-wave sensor, conducting fabric, and an embedded system. The EDA sensor utilizes the relationship between drowsiness and the EDA signal. The EDA sensors were made using a conducting fabric instead of silver chloride electrodes, as a more practical and practically wearable device. The pulse-wave sensor measurement system, which is widely applied in oriental medicinal practices, is also a strong element in e-health monitoring systems. The EDA and pulse-wave signal acquisition module was constructed by connecting the sensor to the glove via a conductive fabric. The signal acquisition module is then connected to a personal computer that displays the results of the EDA and pulse-wave signal processing analysis and gives accurate feedback to the user. This system is designed for a number of applications for the e-health services, including drowsiness detection and oriental medicine.

  8. Physical Human Activity Recognition Using Wearable Sensors

    Directory of Open Access Journals (Sweden)

    Ferhat Attal

    2015-12-01

    Full Text Available This paper presents a review of different classification techniques used to recognize human activities from wearable inertial sensor data. Three inertial sensor units were used in this study and were worn by healthy subjects at key points of upper/lower body limbs (chest, right thigh and left ankle. Three main steps describe the activity recognition process: sensors’ placement, data pre-processing and data classification. Four supervised classification techniques namely, k-Nearest Neighbor (k-NN, Support Vector Machines (SVM, Gaussian Mixture Models (GMM, and Random Forest (RF as well as three unsupervised classification techniques namely, k-Means, Gaussian mixture models (GMM and Hidden Markov Model (HMM, are compared in terms of correct classification rate, F-measure, recall, precision, and specificity. Raw data and extracted features are used separately as inputs of each classifier. The feature selection is performed using a wrapper approach based on the RF algorithm. Based on our experiments, the results obtained show that the k-NN classifier provides the best performance compared to other supervised classification algorithms, whereas the HMM classifier is the one that gives the best results among unsupervised classification algorithms. This comparison highlights which approach gives better performance in both supervised and unsupervised contexts. It should be noted that the obtained results are limited to the context of this study, which concerns the classification of the main daily living human activities using three wearable accelerometers placed at the chest, right shank and left ankle of the subject.

  9. Active Pixel Sensors: Are CCD's Dinosaurs?

    Science.gov (United States)

    Fossum, Eric R.

    1993-01-01

    Charge-coupled devices (CCD's) are presently the technology of choice for most imaging applications. In the 23 years since their invention in 1970, they have evolved to a sophisticated level of performance. However, as with all technologies, we can be certain that they will be supplanted someday. In this paper, the Active Pixel Sensor (APS) technology is explored as a possible successor to the CCD. An active pixel is defined as a detector array technology that has at least one active transistor within the pixel unit cell. The APS eliminates the need for nearly perfect charge transfer -- the Achilles' heel of CCDs. This perfect charge transfer makes CCD's radiation 'soft,' difficult to use under low light conditions, difficult to manufacture in large array sizes, difficult to integrate with on-chip electronics, difficult to use at low temperatures, difficult to use at high frame rates, and difficult to manufacture in non-silicon materials that extend wavelength response.

  10. Towards Activity Context using Software Sensors

    Directory of Open Access Journals (Sweden)

    Kamran Taj Pathan

    2009-06-01

    Full Text Available Service-Oriented Computing delivers the promise of configuring and reconfiguring software systems to address user's needs in a dynamic way. Context-aware computing promises to capture the user's needs and hence the requirements they have on systems. The marriage of both can deliver ad-hoc software solutions relevant to the user in the most current fashion. However, here it is a key to gather information on the users' activity (that is what they are doing. Traditionally any context sensing was conducted with hardware sensors. However, software can also play the same role and in some situations will be more useful to sense the activity of the user. Furthermore they can make use of the fact that Service-oriented systems exchange information through standard protocols. In this paper we discuss our proposed approach to sense the activity of the user making use of software.

  11. Development of a hexavalent chromium ISFET sensor with a polymeric membrane including tributylphosphate

    Energy Technology Data Exchange (ETDEWEB)

    Zazoua, A. [Universite de Annaba, BP 12, El-Hadjar, Annaba (Algeria); Zougar, S. [Universite de Annaba, BP 12, El-Hadjar, Annaba (Algeria); Kherrat, R. [Universite de Annaba, BP 12, El-Hadjar, Annaba (Algeria); Samar, M.H. [Universite de Annaba, BP 12, El-Hadjar, Annaba (Algeria); Jaffrezic-Renault, N. [CEGELY-UMR 5005 CNRS, Ecole centrale de Lyon, 69134 Ecully cedex (France)]. E-mail: Nicole.Jaffrezic@ec-lyon.fr; Errachid, A. [Center of Reference for Bioengineering in Catalonia (CREBEC), Laboratory of Nanobioengineering, Parc Cientific de Barcelona, Universidad de Barcelona C/ Josep Samitier 1-5, 08028 Barcelona (Spain); Abbaci, A. [Universite de Annaba, BP 12, El-Hadjar, Annaba (Algeria)

    2006-03-15

    This paper presents a first report on chromium ISFET (ion-sensitive field effect transistor) based on a polymeric membrane (siloprene) including an ionophore (tributylphosphate) sensitive for hexavalent chromium. The sensor sensitivity as a function of the pH was studied; its value is minimum in a pH interval from 5.5 to 7.5. The sensitivity for hexavalent chromium was found to be 15 mV/loga {sub Cr{sup 6+}} in the range of 10{sup -4} to 10{sup -2} M. The detection limit was found to be 10{sup -5} M. The studied interfering ions are Pb(II) and Cd(II) that do not represent a great perturbation upon the response for hexavalent chromium.

  12. Development of a hexavalent chromium ISFET sensor with a polymeric membrane including tributylphosphate

    International Nuclear Information System (INIS)

    Zazoua, A.; Zougar, S.; Kherrat, R.; Samar, M.H.; Jaffrezic-Renault, N.; Errachid, A.; Abbaci, A.

    2006-01-01

    This paper presents a first report on chromium ISFET (ion-sensitive field effect transistor) based on a polymeric membrane (siloprene) including an ionophore (tributylphosphate) sensitive for hexavalent chromium. The sensor sensitivity as a function of the pH was studied; its value is minimum in a pH interval from 5.5 to 7.5. The sensitivity for hexavalent chromium was found to be 15 mV/loga Cr 6+ in the range of 10 -4 to 10 -2 M. The detection limit was found to be 10 -5 M. The studied interfering ions are Pb(II) and Cd(II) that do not represent a great perturbation upon the response for hexavalent chromium

  13. Abnormal Activity Detection Using Pyroelectric Infrared Sensors

    Directory of Open Access Journals (Sweden)

    Xiaomu Luo

    2016-06-01

    Full Text Available Healthy aging is one of the most important social issues. In this paper, we propose a method for abnormal activity detection without any manual labeling of the training samples. By leveraging the Field of View (FOV modulation, the spatio-temporal characteristic of human activity is encoded into low-dimension data stream generated by the ceiling-mounted Pyroelectric Infrared (PIR sensors. The similarity between normal training samples are measured based on Kullback-Leibler (KL divergence of each pair of them. The natural clustering of normal activities is discovered through a self-tuning spectral clustering algorithm with unsupervised model selection on the eigenvectors of a modified similarity matrix. Hidden Markov Models (HMMs are employed to model each cluster of normal activities and form feature vectors. One-Class Support Vector Machines (OSVMs are used to profile the normal activities and detect abnormal activities. To validate the efficacy of our method, we conducted experiments in real indoor environments. The encouraging results show that our method is able to detect abnormal activities given only the normal training samples, which aims to avoid the laborious and inconsistent data labeling process.

  14. A method to determine validity and reliability of activity sensors

    NARCIS (Netherlands)

    Boerema, Simone Theresa; Hermens, Hermanus J.

    2013-01-01

    METHOD Four sensors were securely fastened to a mechanical oscillator (Vibration Exciter, type 4809, Brüel & Kjær) and moved at various frequencies (6.67Hz; 13.45Hz; 19.88Hz) within the range of human physical activity. For each of the three sensor axes, the sensors were simultaneously moved for

  15. First Results from Cherwell, a Monolithic Active Pixel Sensor for Particle Physics

    CERN Document Server

    Nooney, Tamsin; Borri, Marcello; Crooks, Jamie; Headspith, Jon; Inguglia, Gianluca; Kolya, Scott; Lazarus, Ian; Lemmon, Roy; Mylroie-Smith, James; Turchetta, Renato; Velthuis, Jaap; Wilson, Fergus

    2014-01-01

    Cherwell is a CMOS Monolithic Active Pixel Sensor (MAPS) developed for digital calorimetry and charged particle tracking applications. Here, we outline the initial tests carried out to charac- terise the performance of Cherwell, give details of the test beam carried out at CERN and include the first results from this analysis. Three variations of the chip were tested; Type A, a high re- sistivity, low noise sensor, Type B, a standard resisivity, low noise sensor and Type C, a standard resistivity, standard noise sensor. The sensors yield an average RMS noise value per pixel of 9.6 e

  16. Predictive simulations and optimization of nanowire field-effect PSA sensors including screening

    KAUST Repository

    Baumgartner, Stefan; Heitzinger, Clemens; Vacic, Aleksandar; Reed, Mark A

    2013-01-01

    We apply our self-consistent PDE model for the electrical response of field-effect sensors to the 3D simulation of nanowire PSA (prostate-specific antigen) sensors. The charge concentration in the biofunctionalized boundary layer at the semiconductor-electrolyte interface is calculated using the propka algorithm, and the screening of the biomolecules by the free ions in the liquid is modeled by a sensitivity factor. This comprehensive approach yields excellent agreement with experimental current-voltage characteristics without any fitting parameters. Having verified the numerical model in this manner, we study the sensitivity of nanowire PSA sensors by changing device parameters, making it possible to optimize the devices and revealing the attributes of the optimal field-effect sensor. © 2013 IOP Publishing Ltd.

  17. Predictive simulations and optimization of nanowire field-effect PSA sensors including screening

    KAUST Repository

    Baumgartner, Stefan

    2013-05-03

    We apply our self-consistent PDE model for the electrical response of field-effect sensors to the 3D simulation of nanowire PSA (prostate-specific antigen) sensors. The charge concentration in the biofunctionalized boundary layer at the semiconductor-electrolyte interface is calculated using the propka algorithm, and the screening of the biomolecules by the free ions in the liquid is modeled by a sensitivity factor. This comprehensive approach yields excellent agreement with experimental current-voltage characteristics without any fitting parameters. Having verified the numerical model in this manner, we study the sensitivity of nanowire PSA sensors by changing device parameters, making it possible to optimize the devices and revealing the attributes of the optimal field-effect sensor. © 2013 IOP Publishing Ltd.

  18. Characterization of active CMOS sensors for capacitively coupled pixel detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hirono, Toko; Gonella, Laura; Janssen, Jens; Hemperek, Tomasz; Huegging, Fabian; Krueger, Hans; Wermes, Norbert [Institute of Physics, University of Bonn (Germany); Peric, Ivan [Institut fuer Prozessdatenverarbeitung und Elektronik, Karlsruher Institut fuer Technologie, Karlsruhe (Germany)

    2015-07-01

    Active CMOS pixel sensor is one of the most attractive candidates for detectors of upcoming particle physics experiments. In contrast to conventional sensors of hybrid detectors, signal processing circuit can be integrated in the active CMOS sensor. The characterization and optimization of the pixel circuit are indispensable to obtain a good performance from the sensors. The prototype chips of the active CMOS sensor were fabricated in the AMS 180nm and L-Foundry 150 nm CMOS processes, respectively a high voltage and high resistivity technology. Both chips have a charge sensitive amplifier and a comparator in each pixel. The chips are designed to be glued to the FEI4 pixel readout chip. The signals from 3 pixels of the prototype chips are capacitively coupled to the FEI4 input pads. We have performed lab tests and test beams to characterize the prototypes. In this presentation, the measurement results of the active CMOS prototype sensors are shown.

  19. Low Power Camera-on-a-Chip Using CMOS Active Pixel Sensor Technology

    Science.gov (United States)

    Fossum, E. R.

    1995-01-01

    A second generation image sensor technology has been developed at the NASA Jet Propulsion Laboratory as a result of the continuing need to miniaturize space science imaging instruments. Implemented using standard CMOS, the active pixel sensor (APS) technology permits the integration of the detector array with on-chip timing, control and signal chain electronics, including analog-to-digital conversion.

  20. CMOS Active-Pixel Image Sensor With Simple Floating Gates

    Science.gov (United States)

    Fossum, Eric R.; Nakamura, Junichi; Kemeny, Sabrina E.

    1996-01-01

    Experimental complementary metal-oxide/semiconductor (CMOS) active-pixel image sensor integrated circuit features simple floating-gate structure, with metal-oxide/semiconductor field-effect transistor (MOSFET) as active circuit element in each pixel. Provides flexibility of readout modes, no kTC noise, and relatively simple structure suitable for high-density arrays. Features desirable for "smart sensor" applications.

  1. A triboelectric motion sensor in wearable body sensor network for human activity recognition.

    Science.gov (United States)

    Hui Huang; Xian Li; Ye Sun

    2016-08-01

    The goal of this study is to design a novel triboelectric motion sensor in wearable body sensor network for human activity recognition. Physical activity recognition is widely used in well-being management, medical diagnosis and rehabilitation. Other than traditional accelerometers, we design a novel wearable sensor system based on triboelectrification. The triboelectric motion sensor can be easily attached to human body and collect motion signals caused by physical activities. The experiments are conducted to collect five common activity data: sitting and standing, walking, climbing upstairs, downstairs, and running. The k-Nearest Neighbor (kNN) clustering algorithm is adopted to recognize these activities and validate the feasibility of this new approach. The results show that our system can perform physical activity recognition with a successful rate over 80% for walking, sitting and standing. The triboelectric structure can also be used as an energy harvester for motion harvesting due to its high output voltage in random low-frequency motion.

  2. Wearable Wide-Range Strain Sensors Based on Ionic Liquids and Monitoring of Human Activities

    Directory of Open Access Journals (Sweden)

    Shao-Hui Zhang

    2017-11-01

    Full Text Available Wearable sensors for detection of human activities have encouraged the development of highly elastic sensors. In particular, to capture subtle and large-scale body motion, stretchable and wide-range strain sensors are highly desired, but still a challenge. Herein, a highly stretchable and transparent stain sensor based on ionic liquids and elastic polymer has been developed. The as-obtained sensor exhibits impressive stretchability with wide-range strain (from 0.1% to 400%, good bending properties and high sensitivity, whose gauge factor can reach 7.9. Importantly, the sensors show excellent biological compatibility and succeed in monitoring the diverse human activities ranging from the complex large-scale multidimensional motions to subtle signals, including wrist, finger and elbow joint bending, finger touch, breath, speech, swallow behavior and pulse wave.

  3. A solid-state pH sensor for nonaqueous media including ionic liquids.

    Science.gov (United States)

    Thompson, Brianna C; Winther-Jensen, Orawan; Winther-Jensen, Bjorn; MacFarlane, Douglas R

    2013-04-02

    We describe a solid state electrode structure based on a biologically derived proton-active redox center, riboflavin (RFN). The redox reaction of RFN is a pH-dependent process that requires no water. The electrode was fabricated using our previously described 'stuffing' method to entrap RFN into vapor phase polymerized poly(3,4-ethylenedioxythiophene). The electrode is shown to be capable of measuring the proton activity in the form of an effective pH over a range of different water contents including nonaqueous systems and ionic liquids (ILs). This demonstrates that the entrapment of the redox center facilitates direct electron communication with the polymer. This work provides a miniaturizable system to determine pH (effective) in nonaqueous systems as well as in ionic liquids. The ability to measure pH (effective) is an important step toward the ability to customize ILs with suitable pH (effective) for catalytic reactions and biotechnology applications such as protein preservation.

  4. [Effectiveness of mental health training including active listening for managers].

    Science.gov (United States)

    Ikegami, Kazunori; Tagawa, Yoshimasa; Mafune, Kosuke; Hiro, Hisanori; Nagata, Shoji

    2008-07-01

    significant increases post-training in "Job demands", "Worksite support by supervisor" and "Worksite support by co-worker", subscales of the BJSQ 12 items version. Particularly, the "Worksite support by supervisor" subscale increased significantly in 8 of the 47 sections in a comparison among sections. In this present study, we investigated the effectiveness of mental health training including Active Listening for managers, and suggest that to train Active Listening and use it at the worksite possibly strengthens "Worksite support by supervisor".

  5. Active self-testing noise measurement sensors for large-scale environmental sensor networks.

    Science.gov (United States)

    Domínguez, Federico; Cuong, Nguyen The; Reinoso, Felipe; Touhafi, Abdellah; Steenhaut, Kris

    2013-12-13

    Large-scale noise pollution sensor networks consist of hundreds of spatially distributed microphones that measure environmental noise. These networks provide historical and real-time environmental data to citizens and decision makers and are therefore a key technology to steer environmental policy. However, the high cost of certified environmental microphone sensors render large-scale environmental networks prohibitively expensive. Several environmental network projects have started using off-the-shelf low-cost microphone sensors to reduce their costs, but these sensors have higher failure rates and produce lower quality data. To offset this disadvantage, we developed a low-cost noise sensor that actively checks its condition and indirectly the integrity of the data it produces. The main design concept is to embed a 13 mm speaker in the noise sensor casing and, by regularly scheduling a frequency sweep, estimate the evolution of the microphone's frequency response over time. This paper presents our noise sensor's hardware and software design together with the results of a test deployment in a large-scale environmental network in Belgium. Our middle-range-value sensor (around €50) effectively detected all experienced malfunctions, in laboratory tests and outdoor deployments, with a few false positives. Future improvements could further lower the cost of our sensor below €10.

  6. Optical Breath Gas Sensor for Extravehicular Activity Application

    Science.gov (United States)

    Wood, William R.; Casias, Miguel E.; Vakhtin, Andrei B.; Pilgrim, Jeffrey S.; Chullen, Cinda; Falconi, Eric A.; McMillin, Summer

    2013-01-01

    The function of the infrared gas transducer used during extravehicular activity in the current space suit is to measure and report the concentration of carbon dioxide (CO2) in the ventilation loop. The next generation portable life support system (PLSS) requires next generation CO2 sensing technology with performance beyond that presently in use on the Space Shuttle/International Space Station extravehicular mobility unit (EMU). Accommodation within space suits demands that optical sensors meet stringent size, weight, and power requirements. A laser diode spectrometer based on wavelength modulation spectroscopy is being developed for this purpose by Vista Photonics, Inc. Two prototype devices were delivered to NASA Johnson Space Center (JSC) in September 2011. The sensors incorporate a laser diode-based CO2 channel that also includes an incidental water vapor (humidity) measurement and a separate oxygen channel using a vertical cavity surface emitting laser. Both prototypes are controlled digitally with a field-programmable gate array/microcontroller architecture. The present development extends and upgrades the earlier hardware to the Advanced PLSS 2.0 test article being constructed and tested at JSC. Various improvements to the electronics and gas sampling are being advanced by this project. The combination of low power electronics with the performance of a long wavelength laser spectrometer enables multi-gas sensors with significantly increased performance over that presently offered in the EMU.

  7. A general framework for sensor-based human activity recognition.

    Science.gov (United States)

    Köping, Lukas; Shirahama, Kimiaki; Grzegorzek, Marcin

    2018-04-01

    Today's wearable devices like smartphones, smartwatches and intelligent glasses collect a large amount of data from their built-in sensors like accelerometers and gyroscopes. These data can be used to identify a person's current activity and in turn can be utilised for applications in the field of personal fitness assistants or elderly care. However, developing such systems is subject to certain restrictions: (i) since more and more new sensors will be available in the future, activity recognition systems should be able to integrate these new sensors with a small amount of manual effort and (ii) such systems should avoid high acquisition costs for computational power. We propose a general framework that achieves an effective data integration based on the following two characteristics: Firstly, a smartphone is used to gather and temporally store data from different sensors and transfer these data to a central server. Thus, various sensors can be integrated into the system as long as they have programming interfaces to communicate with the smartphone. The second characteristic is a codebook-based feature learning approach that can encode data from each sensor into an effective feature vector only by tuning a few intuitive parameters. In the experiments, the framework is realised as a real-time activity recognition system that integrates eight sensors from a smartphone, smartwatch and smartglasses, and its effectiveness is validated from different perspectives such as accuracies, sensor combinations and sampling rates. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. A theoretical approach to photosynthetically active radiation silicon sensor

    International Nuclear Information System (INIS)

    Tamasi, M.J.L.; Martínez Bogado, M.G.

    2013-01-01

    This paper presents a theoretical approach for the development of low cost radiometers to measure photosynthetically active radiation (PAR). Two alternatives are considered: a) glass optical filters attached to a silicon sensor, and b) dielectric coating on a silicon sensor. The devices proposed are based on radiometers previously developed by the Argentine National Atomic Energy Commission. The objective of this work is to adapt these low cost radiometers to construct reliable instruments for measuring PAR. The transmittance of optical filters and sensor response have been analyzed for different dielectric materials, number of layers deposited, and incidence angles. Uncertainties in thickness of layer deposition were evaluated. - Highlights: • Design of radiometers to measure photosynthetically active radiation • The study has used a filter and a Si sensor to modify spectral response. • Dielectric multilayers on glass and silicon sensor • Spectral response related to different incidence angles, materials and spectra

  9. Thin n-in-p planar pixel sensors and active edge sensors for the ATLAS upgrade at HL-LHC

    International Nuclear Information System (INIS)

    Terzo, S; Macchiolo, A; Nisius, R; Paschen, B

    2014-01-01

    Silicon pixel modules employing n-in-p planar sensors with an active thickness of 200 μm, produced at CiS, and 100-200 μm thin active/slim edge sensor devices, produced at VTT in Finland have been interconnected to ATLAS FE-I3 and FE-I4 read-out chips. The thin sensors are designed for high energy physics collider experiments to ensure radiation hardness at high fluences. Moreover, the active edge technology of the VTT production maximizes the sensitive region of the assembly, allowing for a reduced overlap of the modules in the pixel layer close to the beam pipe. The CiS production includes also four chip sensors according to the module geometry planned for the outer layers of the upgraded ATLAS pixel detector to be operated at the HL-LHC. The modules have been characterized using radioactive sources in the laboratory and with high precision measurements at beam tests to investigate the hit efficiency and charge collection properties at different bias voltages and particle incidence angles. The performance of the different sensor thicknesses and edge designs are compared before and after irradiation up to a fluence of 1.4 × 10 16 n eq /cm 2

  10. CMOS Active Pixel Sensor Technology and Reliability Characterization Methodology

    Science.gov (United States)

    Chen, Yuan; Guertin, Steven M.; Pain, Bedabrata; Kayaii, Sammy

    2006-01-01

    This paper describes the technology, design features and reliability characterization methodology of a CMOS Active Pixel Sensor. Both overall chip reliability and pixel reliability are projected for the imagers.

  11. Human Activity Recognition from Body Sensor Data using Deep Learning.

    Science.gov (United States)

    Hassan, Mohammad Mehedi; Huda, Shamsul; Uddin, Md Zia; Almogren, Ahmad; Alrubaian, Majed

    2018-04-16

    In recent years, human activity recognition from body sensor data or wearable sensor data has become a considerable research attention from academia and health industry. This research can be useful for various e-health applications such as monitoring elderly and physical impaired people at Smart home to improve their rehabilitation processes. However, it is not easy to accurately and automatically recognize physical human activity through wearable sensors due to the complexity and variety of body activities. In this paper, we address the human activity recognition problem as a classification problem using wearable body sensor data. In particular, we propose to utilize a Deep Belief Network (DBN) model for successful human activity recognition. First, we extract the important initial features from the raw body sensor data. Then, a kernel principal component analysis (KPCA) and linear discriminant analysis (LDA) are performed to further process the features and make them more robust to be useful for fast activity recognition. Finally, the DBN is trained by these features. Various experiments were performed on a real-world wearable sensor dataset to verify the effectiveness of the deep learning algorithm. The results show that the proposed DBN outperformed other algorithms and achieves satisfactory activity recognition performance.

  12. Pulse-driven magnetoimpedance sensor detection of cardiac magnetic activity.

    Directory of Open Access Journals (Sweden)

    Shinsuke Nakayama

    Full Text Available This study sought to establish a convenient method for detecting biomagnetic activity in the heart. Electrical activity of the heart simultaneously induces a magnetic field. Detection of this magnetic activity will enable non-contact, noninvasive evaluation to be made. We improved the sensitivity of a pulse-driven magnetoimpedance (PMI sensor, which is used as an electric compass in mobile phones and as a motion sensor of the operation handle in computer games, toward a pico-Tesla (pT level, and measured magnetic fields on the surface of the thoracic wall in humans. The changes in magnetic field detected by this sensor synchronized with the electric activity of the electrocardiogram (ECG. The shape of the magnetic wave was largely altered by shifting the sensor position within 20 mm in parallel and/or perpendicular to the thoracic wall. The magnetic activity was maximal in the 4th intercostals near the center of the sterna. Furthermore, averaging the magnetic activity at 15 mm in the distance between the thoracic wall and the sensor demonstrated magnetic waves mimicking the P wave and QRS complex. The present study shows the application of PMI sensor in detecting cardiac magnetic activity in several healthy subjects, and suggests future applications of this technology in medicine and biology.

  13. The Sandia MEMS passive shock sensor : FY07 maturation activities.

    Energy Technology Data Exchange (ETDEWEB)

    Houston, Jack E.; Blecke, Jill; Mitchell, John Anthony; Wittwer, Jonathan W.; Crowson, Douglas A.; Clemens, Rebecca C.; Walraven, Jeremy Allen; Epp, David S.; Baker, Michael Sean

    2008-08-01

    This report describes activities conducted in FY07 to mature the MEMS passive shock sensor. The first chapter of the report provides motivation and background on activities that are described in detail in later chapters. The second chapter discusses concepts that are important for integrating the MEMS passive shock sensor into a system. Following these two introductory chapters, the report details modeling and design efforts, packaging, failure analysis and testing and validation. At the end of FY07, the MEMS passive shock sensor was at TRL 4.

  14. Development of Smart Active Layer Sensor (II): Manufacturing and Application

    International Nuclear Information System (INIS)

    Lee, Young Sup; Lee, Sang Il; Kwon, Jae Hwa; Yoon, Dong Jin

    2004-01-01

    This paper is the second part of the study on the development of a smart active layer (SAL) sensor, which consists of two parts. As mentioned in the first paper, structural health monitoring (SHM) is a new technology that is being increasingly applied at the industrial field as a potential approach to improve cost and convenience of structural inspection. Recently, the development of smart sensor is very active for real application. This study has focused on preparation and application study of SAL sensor which is described with regard to the theory and concept of the SAL sensor in the first paper. In order to detect elastic wave, smart piezoelectric sensor, SAL, is fabricated by using a piezoelectric element, shielding layer and protection layer. This protection layer plays an important role in a patched network of distributed piezoelectric sensor and shielding treatment. Four types of SAL sensor are designed/prepared/tested, and these details will be discussed in the paper In this study, SAL sensor ran be feasibly applied to perform structural health monitoring and to detect damage sources which result in elastic waves

  15. MAPLE activities and applications in gas sensors

    Czech Academy of Sciences Publication Activity Database

    Jelínek, Miroslav; Remsa, Jan; Kocourek, Tomáš; Kubešová, B.; Schůrek, J.; Myslík, V.

    2011-01-01

    Roč. 105, č. 3 (2011), 643-649 ISSN 0947-8396 Institutional research plan: CEZ:AV0Z10100522 Keywords : MAPLE * gas sensors * biomedicine * thin films Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.630, year: 2011

  16. Molecular detection by active Fano-sensor

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Yifei; Guo, Zhongyi [School of Computer and Information, Hefei University of Technology, Hefei, 230009 (China)

    2017-04-15

    The optical properties and sensing performances of the molecular sensors based on plasmonic Fano-resonance (PFR) nanostructures have been numerically investigated in detail. The on-resonance sensor, in which the Fano-resonance position is overlapping with the absorption-band of the detected molecules perfectly, reveals a powerful ability to detect the molecules with a low concentration or thin thickness. By the bias-modulation of a single-layer graphene, the Fano-resonance position of the nanostructures can be tuned effectively. On being modulated properly, the PFR sensor shows an ultrahigh performance because of the unprecedentedly high overlap of the Fano-resonance position with the absorption-band of molecules, which is enabling superior signal strength in the molecular detections based on their vibrational fingerprints. Our proposed strategy may enable the development of dynamic sensors and open exciting prospects for bio-sensing. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. CMOS Active Pixel Sensor Star Tracker with Regional Electronic Shutter

    Science.gov (United States)

    Yadid-Pecht, Orly; Pain, Bedabrata; Staller, Craig; Clark, Christopher; Fossum, Eric

    1996-01-01

    The guidance system in a spacecraft determines spacecraft attitude by matching an observed star field to a star catalog....An APS(active pixel sensor)-based system can reduce mass and power consumption and radiation effects compared to a CCD(charge-coupled device)-based system...This paper reports an APS (active pixel sensor) with locally variable times, achieved through individual pixel reset (IPR).

  18. Better physical activity classification using smartphone acceleration sensor.

    Science.gov (United States)

    Arif, Muhammad; Bilal, Mohsin; Kattan, Ahmed; Ahamed, S Iqbal

    2014-09-01

    Obesity is becoming one of the serious problems for the health of worldwide population. Social interactions on mobile phones and computers via internet through social e-networks are one of the major causes of lack of physical activities. For the health specialist, it is important to track the record of physical activities of the obese or overweight patients to supervise weight loss control. In this study, acceleration sensor present in the smartphone is used to monitor the physical activity of the user. Physical activities including Walking, Jogging, Sitting, Standing, Walking upstairs and Walking downstairs are classified. Time domain features are extracted from the acceleration data recorded by smartphone during different physical activities. Time and space complexity of the whole framework is done by optimal feature subset selection and pruning of instances. Classification results of six physical activities are reported in this paper. Using simple time domain features, 99 % classification accuracy is achieved. Furthermore, attributes subset selection is used to remove the redundant features and to minimize the time complexity of the algorithm. A subset of 30 features produced more than 98 % classification accuracy for the six physical activities.

  19. Active pixel sensor array with electronic shuttering

    Science.gov (United States)

    Fossum, Eric R. (Inventor)

    2002-01-01

    An active pixel cell includes electronic shuttering capability. The cell can be shuttered to prevent additional charge accumulation. One mode transfers the current charge to a storage node that is blocked against accumulation of optical radiation. The charge is sampled from a floating node. Since the charge is stored, the node can be sampled at the beginning and the end of every cycle. Another aspect allows charge to spill out of the well whenever the charge amount gets higher than some amount, thereby providing anti blooming.

  20. A novel bicistronic sensor vector for detecting caspase-3 activation.

    Science.gov (United States)

    Vagner, Tatyana; Mouravlev, Alexandre; Young, Deborah

    2015-01-01

    Apoptosis is involved in pathological cell death of a wide range of human diseases. One of the most important biochemical markers of apoptosis is activation of caspase-3. Ability to detect caspase-3 activation early in the pathological process is important for determining the timing for interfering with apoptosis initiation and prevention of cell damage. Techniques allowing detection of caspase-3 activity at a single cell level show increased sensitivity, compared to biochemical assays; therefore, we developed a novel bicistronic caspase-3 sensor vector enabling detection of caspase-3 activity in individual cells. We employed green fluorescent protein (GFP) as a reporter for caspase-3 activation in our constructs and assessed the functionality of the generated constructs in transiently transfected Neuro2A and HEK293 cells under basal conditions and following application of okadaic acid (OA) or staurosporine (STS) to induce apoptosis. To ensure responsiveness of the new sensor vector to active caspase-3, we co-transfected the sensor with plasmid(s) overexpressing active caspase-3 and quantified GFP fluorescence using a plate reader. We observed an increase in GFP expression in cells transfected with the new bicistronic caspase-3 sensor in response to both OA and STS. We also showed a significant increase in GFP fluorescence intensity in cells co-expressing the sensor with the plasmid(s) encoding active caspase-3. We generated a novel bicistronic caspase-3 sensor vector which relies on a transcription factor/response element system. The obtained sensor combines high sensitivity of the single cell level detection with the possibility of automated quantification. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Calibrating a novel multi-sensor physical activity measurement system

    International Nuclear Information System (INIS)

    John, D; Sasaki, J E; Howe, C A; Freedson, P S; Liu, S; Gao, R X; Staudenmayer, J

    2011-01-01

    Advancing the field of physical activity (PA) monitoring requires the development of innovative multi-sensor measurement systems that are feasible in the free-living environment. The use of novel analytical techniques to combine and process these multiple sensor signals is equally important. This paper describes a novel multi-sensor 'integrated PA measurement system' (IMS), the lab-based methodology used to calibrate the IMS, techniques used to predict multiple variables from the sensor signals, and proposes design changes to improve the feasibility of deploying the IMS in the free-living environment. The IMS consists of hip and wrist acceleration sensors, two piezoelectric respiration sensors on the torso, and an ultraviolet radiation sensor to obtain contextual information (indoors versus outdoors) of PA. During lab-based calibration of the IMS, data were collected on participants performing a PA routine consisting of seven different ambulatory and free-living activities while wearing a portable metabolic unit (criterion measure) and the IMS. Data analyses on the first 50 adult participants are presented. These analyses were used to determine if the IMS can be used to predict the variables of interest. Finally, physical modifications for the IMS that could enhance the feasibility of free-living use are proposed and refinement of the prediction techniques is discussed

  2. Active Multimodal Sensor System for Target Recognition and Tracking.

    Science.gov (United States)

    Qu, Yufu; Zhang, Guirong; Zou, Zhaofan; Liu, Ziyue; Mao, Jiansen

    2017-06-28

    High accuracy target recognition and tracking systems using a single sensor or a passive multisensor set are susceptible to external interferences and exhibit environmental dependencies. These difficulties stem mainly from limitations to the available imaging frequency bands, and a general lack of coherent diversity of the available target-related data. This paper proposes an active multimodal sensor system for target recognition and tracking, consisting of a visible, an infrared, and a hyperspectral sensor. The system makes full use of its multisensor information collection abilities; furthermore, it can actively control different sensors to collect additional data, according to the needs of the real-time target recognition and tracking processes. This level of integration between hardware collection control and data processing is experimentally shown to effectively improve the accuracy and robustness of the target recognition and tracking system.

  3. Phosphatase activity tunes two-component system sensor detection threshold.

    Science.gov (United States)

    Landry, Brian P; Palanki, Rohan; Dyulgyarov, Nikola; Hartsough, Lucas A; Tabor, Jeffrey J

    2018-04-12

    Two-component systems (TCSs) are the largest family of multi-step signal transduction pathways in biology, and a major source of sensors for biotechnology. However, the input concentrations to which biosensors respond are often mismatched with application requirements. Here, we utilize a mathematical model to show that TCS detection thresholds increase with the phosphatase activity of the sensor histidine kinase. We experimentally validate this result in engineered Bacillus subtilis nitrate and E. coli aspartate TCS sensors by tuning their detection threshold up to two orders of magnitude. We go on to apply our TCS tuning method to recently described tetrathionate and thiosulfate sensors by mutating a widely conserved residue previously shown to impact phosphatase activity. Finally, we apply TCS tuning to engineer B. subtilis to sense and report a wide range of fertilizer concentrations in soil. This work will enable the engineering of tailor-made biosensors for diverse synthetic biology applications.

  4. Wideband CMOS low noise amplifier including an active balun

    NARCIS (Netherlands)

    Blaakmeer, S.C.; Klumperink, Eric A.M.; Leenaerts, D.M.W.; Nauta, Bram

    2007-01-01

    An inductorless LNA with active balun is proposed for multi-standard radio applications between 100MHz and 6GHz [1]. It exploits a combination of a common-gate (CG) stage and an common-source (CS) stage with replica biasing to maximize balanced operation, while simultaneously canceling the noise and

  5. First experimental results on active and slim-edge silicon sensors for XFEL

    International Nuclear Information System (INIS)

    Pancheri, L.; Benkechcache, M. E. A.; Betta, G.-F. Dalla; Xu, H.; Verzellesi, G.; Ronchin, S.; Boscardin, M.; Ratti, L.; Grassi, M.; Lodola, L.; Malcovati, P.; Vacchi, C.; Manghisoni, M.; Re, V.; Traversi, G.; Batignani, G.; Bettarini, S.; Casarosa, G.; Giorgi, M.; Forti, F.

    2016-01-01

    This work presents the first characterization results obtained on a pilot fabrication run of planar sensors, tailored for X-ray imaging applications at FELs, developed in the framework of INFN project PixFEL. Active and slim-edge p-on-n sensors are fabricated on n-type high-resistivity silicon with 450 μm thickness, bonded to a support wafer. Both diodes and pixelated sensors with a pitch of 110 μm are included in the design. Edge structures with different number of guard rings are designed to comply with the large bias voltage required by the application after accumulating an ionizing radiation dose as large as 1GGy. Preliminary results from the electrical characterization of the produced sensors, providing a first assessment of the proposed approach, are discussed. A functional characterization of the sensors with a pulsed infrared laser is also presented, demonstrating the validity of slim-edge configurations.

  6. Validation of mercury tip-switch and accelerometer activity sensors for identifying resting and active behavior in bears

    Science.gov (United States)

    Jasmine Ware,; Rode, Karyn D.; Pagano, Anthony M.; Bromaghin, Jeffrey F.; Robbins, Charles T.; Joy Erlenbach,; Shannon Jensen,; Amy Cutting,; Nicole Nicassio-Hiskey,; Amy Hash,; Owen, Megan A.; Heiko Jansen,

    2015-01-01

    Activity sensors are often included in wildlife transmitters and can provide information on the behavior and activity patterns of animals remotely. However, interpreting activity-sensor data relative to animal behavior can be difficult if animals cannot be continuously observed. In this study, we examined the performance of a mercury tip-switch and a tri-axial accelerometer housed in collars to determine whether sensor data can be accurately classified as resting and active behaviors and whether data are comparable for the 2 sensor types. Five captive bears (3 polar [Ursus maritimus] and 2 brown [U. arctos horribilis]) were fitted with a collar specially designed to internally house the sensors. The bears’ behaviors were recorded, classified, and then compared with sensor readings. A separate tri-axial accelerometer that sampled continuously at a higher frequency and provided raw acceleration values from 3 axes was also mounted on the collar to compare with the lower resolution sensors. Both accelerometers more accurately identified resting and active behaviors at time intervals ranging from 1 minute to 1 hour (≥91.1% accuracy) compared with the mercury tip-switch (range = 75.5–86.3%). However, mercury tip-switch accuracy improved when sampled at longer intervals (e.g., 30–60 min). Data from the lower resolution accelerometer, but not the mercury tip-switch, accurately predicted the percentage of time spent resting during an hour. Although the number of bears available for this study was small, our results suggest that these activity sensors can remotely identify resting versus active behaviors across most time intervals. We recommend that investigators consider both study objectives and the variation in accuracy of classifying resting and active behaviors reported here when determining sampling interval.

  7. Annotating smart environment sensor data for activity learning.

    Science.gov (United States)

    Szewcyzk, S; Dwan, K; Minor, B; Swedlove, B; Cook, D

    2009-01-01

    The pervasive sensing technologies found in smart homes offer unprecedented opportunities for providing health monitoring and assistance to individuals experiencing difficulties living independently at home. In order to monitor the functional health of smart home residents, we need to design technologies that recognize and track the activities that people perform at home. Machine learning techniques can perform this task, but the software algorithms rely upon large amounts of sample data that is correctly labeled with the corresponding activity. Labeling, or annotating, sensor data with the corresponding activity can be time consuming, may require input from the smart home resident, and is often inaccurate. Therefore, in this paper we investigate four alternative mechanisms for annotating sensor data with a corresponding activity label. We evaluate the alternative methods along the dimensions of annotation time, resident burden, and accuracy using sensor data collected in a real smart apartment.

  8. Compositions of graphene materials with metal nanostructures and microstructures and methods of making and using including pressure sensors

    KAUST Repository

    Chen, Ye

    2017-01-26

    Composition comprising at least one graphene material and at least one metal. The metal can be in the form of nanoparticles as well as microflakes, including single crystal microflakes. The metal can be intercalated in the graphene sheets. The composition has high conductivity and flexibility. The composition can be made by a one-pot synthesis in which a graphene material precursor is converted to the graphene material, and the metal precursor is converted to the metal. A reducing solvent or dispersant such as NMP can be used. Devices made from the composition include a pressure sensor which has high sensitivity. Two two- dimension materials can be combined to form a hybrid material.

  9. Human Activity Recognition Using Heterogeneous Sensors

    NARCIS (Netherlands)

    Shoaib, M.

    Physical activities play an important role in our physical and mental well-being. The lack of such activities can negatively affect our well-being. Though people know the importance of physical activities, still they need regular motivational feedback to remain active in their daily life. In order

  10. Active Design Method for the Static Characteristics of a Piezoelectric Six-Axis Force/Torque Sensor

    OpenAIRE

    Liu, Jun; Li, Min; Qin, Lan; Liu, Jingcheng

    2014-01-01

    To address the bottleneck issues of an elastic-style six-axis force/torque sensor (six-axis force sensor), this work proposes a no-elastic piezoelectric six-axis force sensor. The operating principle of the piezoelectric six-axis force sensor is analyzed, and a structural model is constructed. The static-active design theory of the piezoelectric six-axis force sensor is established, including a static analytical/mathematical model and numerical simulation model (finite element model). A piezo...

  11. Pioneer Venus Star Sensor. [active despin control application

    Science.gov (United States)

    Gutshall, R. L.; Thomas, G.

    1979-01-01

    The design predictions and orbital performance verification of the solid state star scanner used in the Onboard Attitude Control of the Pioneer Venus Orbiter and Multiprobe are presented. The star sensor extended the scanner use to active despin control, and it differs from previous sensors in solid state detection, redundant electronics for reliability, larger field of view, and large dynamic spin range. The star scanner hardware and design performance based on the ability to predict all noise sources, signal magnitudes, and expected detection probability are discussed. In-flight data collected to verify sensor ground calibration are tabulated and plotted in predicted accuracy curves. It is concluded that the Pioneer Venus Star Sensor has demonstrated predictable star calibration in the range of .1 magnitude uncertainties and usable star catalogs of 100 stars with very high probabilities of detection, which were much better than expected and well within the mission requirements.

  12. Characterization of active CMOS pixel sensors on high resistive substrate

    Energy Technology Data Exchange (ETDEWEB)

    Hirono, Toko; Hemperek, Tomasz; Huegging, Fabian; Krueger, Hans; Rymaszewski, Piotr; Wermes, Norbert [Physikalisches Institut, Universitaet Bonn, Bonn (Germany)

    2016-07-01

    Active CMOS pixel sensors are very attractive as radiation imaging pixel detector because they do not need cost-intensive fine pitch bump bonding. High radiation tolerance and time resolution are required to apply those sensors to upcoming particle physics experiments. To achieve these requirements, the active CMOS pixel sensors were developed on high resistive substrates. Signal charges are collected faster by drift in high resistive substrates than in standard low resistive substrates yielding also a higher radiation tolerance. A prototype of the active CMOS pixel sensor has been fabricated in the LFoundry 150 nm CMOS process on 2 kΩcm substrate. This prototype chip was thinned down to 300 μm and the backside has been processed and can contacted by an aluminum contact. The breakdown voltage is around -115 V, and the depletion width has been measured to be as large as 180 μm at a bias voltage of -110 V. Gain and noise of the readout circuitry agree with the designed values. Performance tests in the lab and test beam have been done before and after irradiation with X-rays and neutrons. In this presentation, the measurement results of the active CMOS prototype sensors are shown.

  13. Embedded Triboelectric Active Sensors for Real-Time Pneumatic Monitoring.

    Science.gov (United States)

    Fu, Xian Peng; Bu, Tian Zhao; Xi, Feng Ben; Cheng, Ting Hai; Zhang, Chi; Wang, Zhong Lin

    2017-09-20

    Pneumatic monitoring sensors have great demands for power supply in cylinder systems. Here, we present an embedded sliding triboelectric nanogenerator (TENG) in air cylinder as active sensors for position and velocity monitoring. The embedded TENG is composed of a circular poly(tetrafluoroethylene) polymer and a triangular copper electrode. The working mechanism as triboelectric active sensors and electric output performance are systematically investigated. By integrating into the pneumatic system, the embedded triboelectric active sensors have been used for real-time air pressure/flow monitoring and energy storage. Air pressures are measured from 0.04 to 0.12 MPa at a step of 0.02 MPa with a sensitivity of 49.235 V/MPa, as well as airflow from 50 to 250 L/min at a step of 50 L/min with a sensitivity of 0.002 μA·min/L. This work has first demonstrated triboelectric active sensors for pneumatic monitoring and may promote the development of TENG in intelligent pneumatic system.

  14. Active Sensing System with In Situ Adjustable Sensor Morphology

    Science.gov (United States)

    Nurzaman, Surya G.; Culha, Utku; Brodbeck, Luzius; Wang, Liyu; Iida, Fumiya

    2013-01-01

    Background Despite the widespread use of sensors in engineering systems like robots and automation systems, the common paradigm is to have fixed sensor morphology tailored to fulfill a specific application. On the other hand, robotic systems are expected to operate in ever more uncertain environments. In order to cope with the challenge, it is worthy of note that biological systems show the importance of suitable sensor morphology and active sensing capability to handle different kinds of sensing tasks with particular requirements. Methodology This paper presents a robotics active sensing system which is able to adjust its sensor morphology in situ in order to sense different physical quantities with desirable sensing characteristics. The approach taken is to use thermoplastic adhesive material, i.e. Hot Melt Adhesive (HMA). It will be shown that the thermoplastic and thermoadhesive nature of HMA enables the system to repeatedly fabricate, attach and detach mechanical structures with a variety of shape and size to the robot end effector for sensing purposes. Via active sensing capability, the robotic system utilizes the structure to physically probe an unknown target object with suitable motion and transduce the arising physical stimuli into information usable by a camera as its only built-in sensor. Conclusions/Significance The efficacy of the proposed system is verified based on two results. Firstly, it is confirmed that suitable sensor morphology and active sensing capability enables the system to sense different physical quantities, i.e. softness and temperature, with desirable sensing characteristics. Secondly, given tasks of discriminating two visually indistinguishable objects with respect to softness and temperature, it is confirmed that the proposed robotic system is able to autonomously accomplish them. The way the results motivate new research directions which focus on in situ adjustment of sensor morphology will also be discussed. PMID:24416094

  15. Active sensing system with in situ adjustable sensor morphology.

    Science.gov (United States)

    Nurzaman, Surya G; Culha, Utku; Brodbeck, Luzius; Wang, Liyu; Iida, Fumiya

    2013-01-01

    Despite the widespread use of sensors in engineering systems like robots and automation systems, the common paradigm is to have fixed sensor morphology tailored to fulfill a specific application. On the other hand, robotic systems are expected to operate in ever more uncertain environments. In order to cope with the challenge, it is worthy of note that biological systems show the importance of suitable sensor morphology and active sensing capability to handle different kinds of sensing tasks with particular requirements. This paper presents a robotics active sensing system which is able to adjust its sensor morphology in situ in order to sense different physical quantities with desirable sensing characteristics. The approach taken is to use thermoplastic adhesive material, i.e. Hot Melt Adhesive (HMA). It will be shown that the thermoplastic and thermoadhesive nature of HMA enables the system to repeatedly fabricate, attach and detach mechanical structures with a variety of shape and size to the robot end effector for sensing purposes. Via active sensing capability, the robotic system utilizes the structure to physically probe an unknown target object with suitable motion and transduce the arising physical stimuli into information usable by a camera as its only built-in sensor. The efficacy of the proposed system is verified based on two results. Firstly, it is confirmed that suitable sensor morphology and active sensing capability enables the system to sense different physical quantities, i.e. softness and temperature, with desirable sensing characteristics. Secondly, given tasks of discriminating two visually indistinguishable objects with respect to softness and temperature, it is confirmed that the proposed robotic system is able to autonomously accomplish them. The way the results motivate new research directions which focus on in situ adjustment of sensor morphology will also be discussed.

  16. [Active crop canopy sensor-based nitrogen diagnosis for potato].

    Science.gov (United States)

    Yu, Jing; Li, Fei; Qin, Yong-Lin; Fan, Ming-Shou

    2013-11-01

    In the present study, two potato experiments involving different N rates in 2011 were conducted in Wuchuan County and Linxi County, Inner Mongolia. Normalized difference vegetation index (NDVI) was collected by an active GreenSeeker crop canopy sensor to estimate N status of potato. The results show that the NDVI readings were poorly correlated with N nutrient indicators of potato at vegetative Growth stage due to the influence of soil background. With the advance of growth stages, NDVI values were exponentially related to plant N uptake (R2 = 0.665) before tuber bulking stage and were linearly related to plant N concentration (R2 = 0.699) when plant fully covered soil. In conclusion, GreenSeeker active crop sensor is a promising tool to estimate N status for potato plants. The findings from this study may be useful for developing N recommendation method based on active crop canopy sensor.

  17. Active Magnetic Shielding with magneto-impedance sensor

    International Nuclear Information System (INIS)

    Okazaki, Yasuo; Yanase, Shunji; Sugimoto, Noriko

    2002-01-01

    Active shielding effect was examined in a negative feedback circuit system consisting of a magneto-impedance effective sensor, an amplifier and a canceling coil to compensate external magnetic field noise. The phase difference between the input and output sensor signals in a loop was less than 90 degree up to 20,000 Hz. An excellent frequency characteristic of active shielding effectiveness, 48 dB was obtained for the external magnetic field at the frequency of 0 - 2,000 Hz. (Author)

  18. Device Simulation of Monolithic Active Pixel Sensors: Radiation Damage Effects

    International Nuclear Information System (INIS)

    Fourches, N.T.

    2009-01-01

    Vertexing for the future International Linear Collider represents a challenging goal because of the high spatial resolution required with low material budget and high ionizing radiation tolerance. CMOS Monolithic Active Pixel Sensors (MAPS) represent a good potential solution for this purpose. Up to now many MAPS sensors have been developed. They are based on various architectures and manufactured in different processes. However, up so far, the sensor diode has not been the subject of extensive modelization and simulation. Published simulation studies of sensor-signal formation have been less numerous than measurements on real sensors. This is a cause for concern because such sensor is physically based on the partially depleted diode, in the vicinity of which the electric field collects the minority carriers generated by an incident MIP (minimum ionizing particle). Although the microscopic mechanisms are well known and modelled, the global physical mechanisms for signal formation are not very rigorously established. This is partly due to the presence of a predominant diffusion component in the charge transport. We present here simulations mainly based on the S-PISCES code, in which physical mechanisms affecting transport are taken into account. Diffusion, influence of residual carrier concentration due to the doping level in the sensitive volume, and more importantly charge trapping due to deep levels in the active (detecting) layer are studied together with geometric aspects. The effect of neutron irradiation is studied to assess the effects of deep traps. A comparison with available experimental data, obtained on processed MAPS before or after neutron irradiation will be introduced. Simulated reconstruction of the Minimum Ionizing Particle (MIP) point of impact in two dimensions is also investigated. For further steps, guidelines for process choices of next Monolithic Active Pixel Sensors are introduced. (authors)

  19. A Low Power, Parallel Wearable Multi-Sensor System for Human Activity Evaluation.

    Science.gov (United States)

    Li, Yuecheng; Jia, Wenyan; Yu, Tianjian; Luan, Bo; Mao, Zhi-Hong; Zhang, Hong; Sun, Mingui

    2015-04-01

    In this paper, the design of a low power heterogeneous wearable multi-sensor system, built with Zynq System-on-Chip (SoC), for human activity evaluation is presented. The powerful data processing capability and flexibility of this SoC represent significant improvements over our previous ARM based system designs. The new system captures and compresses multiple color images and sensor data simultaneously. Several strategies are adopted to minimize power consumption. Our wearable system provides a new tool for the evaluation of human activity, including diet, physical activity and lifestyle.

  20. Recognizing Multi-user Activities using Body Sensor Networks

    DEFF Research Database (Denmark)

    Gu, Tao; Wang, Liang; Chen, Hanhua

    2011-01-01

    The advances of wireless networking and sensor technology open up an interesting opportunity to infer human activities in a smart home environment. Existing work in this paradigm focuses mainly on recognizing activities of a single user. In this work, we address the fundamental problem...... activity classes of data—for building activity models and design a scalable, noise-resistant, Emerging Pattern based Multi-user Activity Recognizer (epMAR) to recognize both single- and multi-user activities. We develop a multi-modal, wireless body sensor network for collecting real-world traces in a smart...... home environment, and conduct comprehensive empirical studies to evaluate our system. Results show that epMAR outperforms existing schemes in terms of accuracy, scalability and robustness....

  1. Monolithic active pixel sensors (MAPS) in a VLSI CMOS technology

    CERN Document Server

    Turchetta, R; Manolopoulos, S; Tyndel, M; Allport, P P; Bates, R; O'Shea, V; Hall, G; Raymond, M

    2003-01-01

    Monolithic Active Pixel Sensors (MAPS) designed in a standard VLSI CMOS technology have recently been proposed as a compact pixel detector for the detection of high-energy charged particle in vertex/tracking applications. MAPS, also named CMOS sensors, are already extensively used in visible light applications. With respect to other competing imaging technologies, CMOS sensors have several potential advantages in terms of low cost, low power, lower noise at higher speed, random access of pixels which allows windowing of region of interest, ability to integrate several functions on the same chip. This brings altogether to the concept of 'camera-on-a-chip'. In this paper, we review the use of CMOS sensors for particle physics and we analyse their performances in term of the efficiency (fill factor), signal generation, noise, readout speed and sensor area. In most of high-energy physics applications, data reduction is needed in the sensor at an early stage of the data processing before transfer of the data to ta...

  2. Single chip camera active pixel sensor

    Science.gov (United States)

    Shaw, Timothy (Inventor); Pain, Bedabrata (Inventor); Olson, Brita (Inventor); Nixon, Robert H. (Inventor); Fossum, Eric R. (Inventor); Panicacci, Roger A. (Inventor); Mansoorian, Barmak (Inventor)

    2003-01-01

    A totally digital single chip camera includes communications to operate most of its structure in serial communication mode. The digital single chip camera include a D/A converter for converting an input digital word into an analog reference signal. The chip includes all of the necessary circuitry for operating the chip using a single pin.

  3. Active Low Intrusion Hybrid Monitor for Wireless Sensor Networks.

    Science.gov (United States)

    Navia, Marlon; Campelo, Jose C; Bonastre, Alberto; Ors, Rafael; Capella, Juan V; Serrano, Juan J

    2015-09-18

    Several systems have been proposed to monitor wireless sensor networks (WSN). These systems may be active (causing a high degree of intrusion) or passive (low observability inside the nodes). This paper presents the implementation of an active hybrid (hardware and software) monitor with low intrusion. It is based on the addition to the sensor node of a monitor node (hardware part) which, through a standard interface, is able to receive the monitoring information sent by a piece of software executed in the sensor node. The intrusion on time, code, and energy caused in the sensor nodes by the monitor is evaluated as a function of data size and the interface used. Then different interfaces, commonly available in sensor nodes, are evaluated: serial transmission (USART), serial peripheral interface (SPI), and parallel. The proposed hybrid monitor provides highly detailed information, barely disturbed by the measurement tool (interference), about the behavior of the WSN that may be used to evaluate many properties such as performance, dependability, security, etc. Monitor nodes are self-powered and may be removed after the monitoring campaign to be reused in other campaigns and/or WSNs. No other hardware-independent monitoring platforms with such low interference have been found in the literature.

  4. Sensor fusion for active vibration isolation in precision equipment

    NARCIS (Netherlands)

    Tjepkema, D.; van Dijk, Johannes; Soemers, Herman

    2012-01-01

    Sensor fusion is a promising control strategy to improve the performance of active vibration isolation systems that are used in precision equipment. Normally, those vibration isolation systems are only capable of realizing a low transmissibility. Additional objectives are to increase the damping

  5. High-power fiber optic cable with integrated active sensors for live process monitoring

    Science.gov (United States)

    Blomster, Ola; Blomqvist, Mats; Bergstrand, Hans; Pålsson, Magnus

    2012-03-01

    In industrial applications using high-brilliance lasers at power levels up to and exceeding 20 kW and similarly direct diode lasers of 10 kW, there is an increasing demand to continuously monitor component status even in passive components such as fiber-optic cables. With fiber-optic cables designed according to the European Automotive Industry fiber standard interface there is room for integrating active sensors inside the connectors. In this paper we present the integrated active sensors in the new Optoskand QD fiber-optic cable designed to handle extreme levels of power losses, and how these sensors can be employed in industrial manufacturing. The sensors include photo diodes for detection of scattered light inside the fiber connector, absolute temperature of the fiber connector, difference in temperature of incoming and outgoing cooling water, and humidity measurement inside the fiber connector. All these sensors are connected to the fiber interlock system, where interlock break enable functions can be activated when measured signals are higher than threshold levels. It is a very fast interlock break system as the control of the signals is integrated in the electronics inside the fiber connector. Also, since all signals can be logged it is possible to evaluate what happened inside the connector before the interlock break instance. The communication to the fiber-optic connectors is via a CAN interface. Thus it is straightforward to develop the existing laser host control to also control the CAN-messages from the QD sensors.

  6. Active sensing and its application to sensor node reconfiguration.

    Science.gov (United States)

    Lee, Sooyong

    2014-10-08

    This paper presents a perturbation/correlation-based active sensing method and its application to sensor node configuration for environment monitoring. Sensor networks are widely used as data measurement tools, especially in dangerous environments. For large scale environment monitoring, a large number of nodes is required. For optimal measurements, the placement of nodes is very important. Nonlinear spring force-based configuration is introduced. Perturbation/correlation-based estimation of the gradient is developed and it is much more robust because it does not require any differentiation. An algorithm for tuning the stiffness using the estimated gradient for node reconfiguration is presented. The performance of the proposed algorithm is discussed with simulation results.

  7. Learning Activity Predictors from Sensor Data: Algorithms, Evaluation, and Applications.

    Science.gov (United States)

    Minor, Bryan; Doppa, Janardhan Rao; Cook, Diane J

    2017-12-01

    Recent progress in Internet of Things (IoT) platforms has allowed us to collect large amounts of sensing data. However, there are significant challenges in converting this large-scale sensing data into decisions for real-world applications. Motivated by applications like health monitoring and intervention and home automation we consider a novel problem called Activity Prediction , where the goal is to predict future activity occurrence times from sensor data. In this paper, we make three main contributions. First, we formulate and solve the activity prediction problem in the framework of imitation learning and reduce it to a simple regression learning problem. This approach allows us to leverage powerful regression learners that can reason about the relational structure of the problem with negligible computational overhead. Second, we present several metrics to evaluate activity predictors in the context of real-world applications. Third, we evaluate our approach using real sensor data collected from 24 smart home testbeds. We also embed the learned predictor into a mobile-device-based activity prompter and evaluate the app for 9 participants living in smart homes. Our results indicate that our activity predictor performs better than the baseline methods, and offers a simple approach for predicting activities from sensor data.

  8. Electronic dosimetry and neutron metrology by CMOS active pixel sensor

    International Nuclear Information System (INIS)

    Vanstalle, M.

    2011-01-01

    This work aims at demonstrating the possibility to use active pixel sensors as operational neutron dosemeters. To do so, the sensor that has been used has to be γ-transparent and to be able to detect neutrons on a wide energy range with a high detection efficiency. The response of the device, made of the CMOS sensor MIMOSA-5 and a converter in front of the sensor (polyethylene for fast neutron detection and 10 B for thermal neutron detection), has been compared with Monte Carlo simulations carried out with MCNPX and GEANT4. These codes have been before-hand validated to check they can be used properly for our application. Experiments to characterize the sensor have been performed at IPHC and at IRSN/LMDN (Cadarache). The results of the sensor irradiation to photon sources and mixed field ( 241 AmBe source) show the γ-transparency of the sensor by applying an appropriate threshold on the deposited energy (around 100 keV). The associated detection efficiency is satisfactory with a value of 10 -3 , in good agreement with MCNPX and GEANT4. Other features of the device have been tested with the same source, like the angular response. The last part of this work deals with the detection of thermal neutrons (eV-neutrons). Assays have been done in Cadarache (IRSN) with a 252 Cf source moderated with heavy water (with and without cadmium shell). Results asserted a very high detection efficiency (up to 6*10 -3 for a pure 10 B converter) in good agreement with GEANT4. (author)

  9. Development of radiation hard CMOS active pixel sensors for HL-LHC

    International Nuclear Information System (INIS)

    Pernegger, Heinz

    2016-01-01

    New pixel detectors, based on commercial high voltage and/or high resistivity full CMOS processes, hold promise as next-generation active pixel sensors for inner and intermediate layers of the upgraded ATLAS tracker. The use of commercial CMOS processes allow cost-effective detector construction and simpler hybridisation techniques. The paper gives an overview of the results obtained on AMS-produced CMOS sensors coupled to the ATLAS Pixel FE-I4 readout chips. The SOI (silicon-on-insulator) produced sensors by XFAB hold great promise as radiation hard SOI-CMOS sensors due to their combination of partially depleted SOI transistors reducing back-gate effects. The test results include pre-/post-irradiation comparison, measurements of charge collection regions as well as test beam results.

  10. Photodiode area effect on performance of X-ray CMOS active pixel sensors

    Science.gov (United States)

    Kim, M. S.; Kim, Y.; Kim, G.; Lim, K. T.; Cho, G.; Kim, D.

    2018-02-01

    Compared to conventional TFT-based X-ray imaging devices, CMOS-based X-ray imaging sensors are considered next generation because they can be manufactured in very small pixel pitches and can acquire high-speed images. In addition, CMOS-based sensors have the advantage of integration of various functional circuits within the sensor. The image quality can also be improved by the high fill-factor in large pixels. If the size of the subject is small, the size of the pixel must be reduced as a consequence. In addition, the fill factor must be reduced to aggregate various functional circuits within the pixel. In this study, 3T-APS (active pixel sensor) with photodiodes of four different sizes were fabricated and evaluated. It is well known that a larger photodiode leads to improved overall performance. Nonetheless, if the size of the photodiode is > 1000 μm2, the degree to which the sensor performance increases as the photodiode size increases, is reduced. As a result, considering the fill factor, pixel-pitch > 32 μm is not necessary to achieve high-efficiency image quality. In addition, poor image quality is to be expected unless special sensor-design techniques are included for sensors with a pixel pitch of 25 μm or less.

  11. Autonomous star tracker based on active pixel sensors (APS)

    Science.gov (United States)

    Schmidt, U.

    2017-11-01

    Star trackers are opto-electronic sensors used onboard of satellites for the autonomous inertial attitude determination. During the last years, star trackers became more and more important in the field of the attitude and orbit control system (AOCS) sensors. High performance star trackers are based up today on charge coupled device (CCD) optical camera heads. The Jena-Optronik GmbH is active in the field of opto-electronic sensors like star trackers since the early 80-ties. Today, with the product family ASTRO5, ASTRO10 and ASTRO15, all marked segments like earth observation, scientific applications and geo-telecom are supplied to European and Overseas customers. A new generation of star trackers can be designed based on the APS detector technical features. The measurement performance of the current CCD based star trackers can be maintained, the star tracker functionality, reliability and robustness can be increased while the unit costs are saved.

  12. Robust Sensor-Orientation-Independent Feature Selection for Animal Activity Recognition on Collar Tags

    NARCIS (Netherlands)

    Kamminga, Jacob Wilhelm; Le Viet Duc, Duc Viet; Meijers, Jan Pieter; Bisby, Helena C.; Meratnia, Nirvana; Havinga, Paul J.M.

    2018-01-01

    Fundamental challenges faced by real-time animal activity recognition include variation in motion data due to changing sensor orientations, numerous features, and energy and processing constraints of animal tags. This paper aims at finding small optimal feature sets that are lightweight and robust

  13. Activity classification based on inertial and barometric pressure sensors at different anatomical locations.

    Science.gov (United States)

    Moncada-Torres, A; Leuenberger, K; Gonzenbach, R; Luft, A; Gassert, R

    2014-07-01

    Miniature, wearable sensor modules are a promising technology to monitor activities of daily living (ADL) over extended periods of time. To assure both user compliance and meaningful results, the selection and placement site of sensors requires careful consideration. We investigated these aspects for the classification of 16 ADL in 6 healthy subjects under laboratory conditions using ReSense, our custom-made inertial measurement unit enhanced with a barometric pressure sensor used to capture activity-related altitude changes. Subjects wore a module on each wrist and ankle, and one on the trunk. Activities comprised whole body movements as well as gross and dextrous upper-limb activities. Wrist-module data outperformed the other locations for the three activity groups. Specifically, overall classification accuracy rates of almost 93% and more than 95% were achieved for the repeated holdout and user-specific validation methods, respectively, for all 16 activities. Including the altitude profile resulted in a considerable improvement of up to 20% in the classification accuracy for stair ascent and descent. The gyroscopes provided no useful information for activity classification under this scheme. The proposed sensor setting could allow for robust long-term activity monitoring with high compliance in different patient populations.

  14. Activity classification based on inertial and barometric pressure sensors at different anatomical locations

    International Nuclear Information System (INIS)

    Moncada-Torres, A; Leuenberger, K; Gassert, R; Gonzenbach, R; Luft, A

    2014-01-01

    Miniature, wearable sensor modules are a promising technology to monitor activities of daily living (ADL) over extended periods of time. To assure both user compliance and meaningful results, the selection and placement site of sensors requires careful consideration. We investigated these aspects for the classification of 16 ADL in 6 healthy subjects under laboratory conditions using ReSense, our custom-made inertial measurement unit enhanced with a barometric pressure sensor used to capture activity-related altitude changes. Subjects wore a module on each wrist and ankle, and one on the trunk. Activities comprised whole body movements as well as gross and dextrous upper-limb activities. Wrist-module data outperformed the other locations for the three activity groups. Specifically, overall classification accuracy rates of almost 93% and more than 95% were achieved for the repeated holdout and user-specific validation methods, respectively, for all 16 activities. Including the altitude profile resulted in a considerable improvement of up to 20% in the classification accuracy for stair ascent and descent. The gyroscopes provided no useful information for activity classification under this scheme. The proposed sensor setting could allow for robust long-term activity monitoring with high compliance in different patient populations. (paper)

  15. Sensor Fusion for Nuclear Proliferation Activity Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Adel Ghanem, Ph D

    2007-03-30

    The objective of Phase 1 of this STTR project is to demonstrate a Proof-of-Concept (PoC) of the Geo-Rad system that integrates a location-aware SmartTag (made by ZonTrak) and a radiation detector (developed by LLNL). It also includes the ability to transmit the collected radiation data and location information to the ZonTrak server (ZonService). The collected data is further transmitted to a central server at LLNL (the Fusion Server) to be processed in conjunction with overhead imagery to generate location estimates of nuclear proliferation and radiation sources.

  16. Wireless sensor networks for active vibration control in automobile structures

    International Nuclear Information System (INIS)

    Mieyeville, Fabien; Navarro, David; Du, Wan; Ichchou, Mohamed; Scorletti, Gérard

    2012-01-01

    Wireless sensor networks (WSNs) are nowadays widely used in monitoring and tracking applications. This paper presents the feasibility of using WSNs in active vibration control strategies. The method employed here involves active-structural acoustic control using piezoelectric sensors distributed on a car structure. This system aims at being merged with a WSN whose head node collects data and processes control laws so as to command piezoelectric actuators wisely placed on the structure. We will study the feasibility of implementing WSNs in active vibration control and introduce a complete design methodology to optimize hardware/software and control law synergy in mechatronic systems. A design space exploration will be conducted so as to identify the best WSN platform and the resulting impact on control. (paper)

  17. Sensor-Based Activity Recognition with Dynamically Added Context

    Directory of Open Access Journals (Sweden)

    Jiahui Wen

    2015-08-01

    Full Text Available An activity recognition system essentially processes raw sensor data and maps them into latent activity classes. Most of the previous systems are built with supervised learning techniques and pre-defined data sources, and result in static models. However, in realistic and dynamic environments, original data sources may fail and new data sources become available, a robust activity recognition system should be able to perform evolution automatically with dynamic sensor availability in dynamic environments. In this paper, we propose methods that automatically incorporate dynamically available data sources to adapt and refine the recognition system at run-time. The system is built upon ensemble classifiers which can automatically choose the features with the most discriminative power. Extensive experimental results with publicly available datasets demonstrate the effectiveness of our methods.

  18. Bend, stretch, and touch: Locating a finger on an actively deformed transparent sensor array.

    Science.gov (United States)

    Sarwar, Mirza Saquib; Dobashi, Yuta; Preston, Claire; Wyss, Justin K M; Mirabbasi, Shahriar; Madden, John David Wyndham

    2017-03-01

    The development of bendable, stretchable, and transparent touch sensors is an emerging technological goal in a variety of fields, including electronic skin, wearables, and flexible handheld devices. Although transparent tactile sensors based on metal mesh, carbon nanotubes, and silver nanowires demonstrate operation in bent configurations, we present a technology that extends the operation modes to the sensing of finger proximity including light touch during active bending and even stretching. This is accomplished using stretchable and ionically conductive hydrogel electrodes, which project electric field above the sensor to couple with and sense a finger. The polyacrylamide electrodes are embedded in silicone. These two widely available, low-cost, transparent materials are combined in a three-step manufacturing technique that is amenable to large-area fabrication. The approach is demonstrated using a proof-of-concept 4 × 4 cross-grid sensor array with a 5-mm pitch. The approach of a finger hovering a few centimeters above the array is readily detectable. Light touch produces a localized decrease in capacitance of 15%. The movement of a finger can be followed across the array, and the location of multiple fingers can be detected. Touch is detectable during bending and stretch, an important feature of any wearable device. The capacitive sensor design can be made more or less sensitive to bending by shifting it relative to the neutral axis. Ultimately, the approach is adaptable to the detection of proximity, touch, pressure, and even the conformation of the sensor surface.

  19. Sensor Data Acquisition and Processing Parameters for Human Activity Classification

    Directory of Open Access Journals (Sweden)

    Sebastian D. Bersch

    2014-03-01

    Full Text Available It is known that parameter selection for data sampling frequency and segmentation techniques (including different methods and window sizes has an impact on the classification accuracy. For Ambient Assisted Living (AAL, no clear information to select these parameters exists, hence a wide variety and inconsistency across today’s literature is observed. This paper presents the empirical investigation of different data sampling rates, segmentation techniques and segmentation window sizes and their effect on the accuracy of Activity of Daily Living (ADL event classification and computational load for two different accelerometer sensor datasets. The study is conducted using an ANalysis Of VAriance (ANOVA based on 32 different window sizes, three different segmentation algorithm (with and without overlap, totaling in six different parameters and six sampling frequencies for nine common classification algorithms. The classification accuracy is based on a feature vector consisting of Root Mean Square (RMS, Mean, Signal Magnitude Area (SMA, Signal Vector Magnitude (here SMV, Energy, Entropy, FFTPeak, Standard Deviation (STD. The results are presented alongside recommendations for the parameter selection on the basis of the best performing parameter combinations that are identified by means of the corresponding Pareto curve.

  20. Motion Sensor Reactivity in Physically Active Young Adults

    Science.gov (United States)

    Behrens, Timothy K.; Dinger, Mary K.

    2007-01-01

    The purpose of this study was to examine whether young adults changed their physical activity (PA) behavior when wearing motion sensors. PA patterns of 119 young adults (M age = 20.82 years, SD = 1.50, M body mass index = 23.93 kg/m[superscript 2] , SD = 4.05) were assessed during 2 consecutive weeks. In Week 1, participants wore an accelerometer.…

  1. Active sensors for health monitoring of aging aerospace structures

    Science.gov (United States)

    Giurgiutiu, Victor; Redmond, James M.; Roach, Dennis P.; Rackow, Kirk

    2000-06-01

    A project to develop non-intrusive active sensors that can be applied on existing aging aerospace structures for monitoring the onset and progress of structural damage (fatigue cracks and corrosion) is presented. The state of the art in active sensors structural health monitoring and damage detection is reviewed. Methods based on (a) elastic wave propagation and (b) electro-mechanical (E/M) impedance technique are cited and briefly discussed. The instrumentation of these specimens with piezoelectric active sensors is illustrated. The main detection strategies (E/M impedance for local area detection and wave propagation for wide area interrogation) are discussed. The signal processing and damage interpretation algorithms are tuned to the specific structural interrogation method used. In the high frequency E/M impedance approach, pattern recognition methods are used to compare impedance signatures taken at various time intervals and to identify damage presence and progression from the change in these signatures. In the wave propagation approach, the acousto- ultrasonic methods identifying additional reflection generated from the damage site and changes in transmission velocity and phase are used. Both approaches benefit from the use of artificial intelligence neural networks algorithms that can extract damage features based on a learning process. Design and fabrication of a set of structural specimens representative of aging aerospace structures is presented. Three built-up specimens, (pristine, with cracks, and with corrosion damage) are used. The specimen instrumentation with active sensors fabricated at the University of South Carolina is illustrated. Preliminary results obtained with the E/M impedance method on pristine and cracked specimens are presented.

  2. Application of activity sensors for estimating behavioral patterns

    Science.gov (United States)

    Roberts, Caleb P.; Cain, James W.; Cox, Robert D.

    2016-01-01

    The increasing use of Global Positioning System (GPS) collars in habitat selection studies provides large numbers of precise location data points with reduced field effort. However, inclusion of activity sensors in many GPS collars also grants the potential to remotely estimate behavioral state. Thus, only using GPS collars to collect location data belies their full capabilities. Coupling behavioral state with location data would allow researchers and managers to refine habitat selection models by using diel behavioral state changes to partition fine-scale temporal shifts in habitat selection. We tested the capability of relatively unsophisticated GPS-collar activity sensors to estimate behavior throughout diel periods using free-ranging female elk (Cervus canadensis) in the Jemez Mountains of north-central New Mexico, USA, 2013–2014. Collars recorded cumulative number of movements (hits) per 15-min recording period immediately preceding GPS fixes at 0000, 0600, 1200, and 1800 hr. We measured diel behavioral patterns of focal elk, categorizing active (i.e., foraging, traveling, vigilant, grooming) and inactive (i.e., resting) states. Active behaviors (foraging, traveling) produced more average hits (0.87 ± 0.69 hits/min, 4.0 ± 2.2 hits/min, respectively; 95% CI) and inactive (resting) behavior fewer hits (−1.1 ± 0.61 95% CI). We differentiated active and inactive behavioral states with a bootstrapped threshold of 5.9 ± 3.9 hits/15-min recording period. Mean cumulative activity-sensor hits corresponded with observed diel behavioral patterns: hits increased during crepuscular (0600, 1800 hr) observations when elk were most active (0000–0600 hr: d = 0.19; 1200–1800 hr: d = 0.64) and decreased during midday and night (0000 hr, 1200 hr) when elk were least active (1800–0000 hr: d = −0.39; 0600–1200 hr: d = −0.43). Even using relatively unsophisticated GPS-collar activity sensors, managers can

  3. Promotion of active ageing combining sensor and social network data.

    Science.gov (United States)

    Bilbao, Aritz; Almeida, Aitor; López-de-Ipiña, Diego

    2016-12-01

    The increase of life expectancy in modern society has caused an increase in elderly population. Elderly people want to live independently in their home environment for as long as possible. However, as we age, our physical skills tend to worsen and our social circle tends to become smaller, something that often leads to a considerable decrease of both our physical and social activities. In this paper, we present an AAL framework developed within the SONOPA project, whose objective is to promote active ageing by combining a social network with information inferred using in-home sensors. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. On drift fields in CMOS monolithic active pixel sensors

    Energy Technology Data Exchange (ETDEWEB)

    Deveaux, Michael [Goethe-Universitaet, Frankfurt (Germany); Collaboration: CBM-MVD-Collaboration

    2016-07-01

    CMOS Monolithic Active Pixel Sensors (MAPS) combine an excellent spatial resolution of few μm with a very low material budget of 0.05% X{sub 0}. To extend their radiation tolerance to the level needed for future experiments like e.g. CBM, it is regularly considered to deplete their active volume. We discuss the limits of this strategy accounting for the specific features of the sensing elements of MAPS. Moreover, we introduce an alternative approach to generate the drift fields needed to provoke a faster charge collection by means of doping gradients.

  5. Packaging of active fiber composites for improved sensor performance

    International Nuclear Information System (INIS)

    Melnykowycz, M; Barbezat, M; Koller, R; Brunner, A J

    2010-01-01

    Active fiber composites (AFC) composed of lead zirconate titanate (PZT) fibers embedded in an epoxy matrix and sandwiched between two interdigitated electrodes provide a thin and flexible smart material device which can act as a sensor or actuator. The thin profiles of AFC make them ideal for integration in glass or carbon fiber composite laminates. However, due to the low tensile limit of the PZT fibers, AFC can fail at strains below the tensile limit of many composites. This makes their use as a component in an active laminate design somewhat undesirable. In the current work, tensile testing of smart laminates composed of AFC integrated in glass fiber laminates was conducted to assess the effectiveness of different packaging strategies for improving AFC sensor performance at high strains relative to the tensile limit of the AFC. AFC were encased in carbon fiber, silicon, and pre-stressed carbon fiber to improve the tensile limit of the AFC when integrated in glass fiber laminates. By laminating AFC with pre-stressed carbon fiber, the tensile limit and strain sensor ability of the AFC were significantly improved. Acoustic emission monitoring was used and the results show that PZT fiber breakage was reduced due to the pre-stressed packaging process

  6. Active Wireless Temperature Sensors for Aerospace Thermal Protection Systems

    Science.gov (United States)

    Milos, Frank S.; Karunaratne, K.; Arnold, Jim (Technical Monitor)

    2002-01-01

    Health diagnostics is an area where major improvements have been identified for potential implementation into the design of new reusable launch vehicles in order to reduce life-cycle costs, to increase safety margins, and to improve mission reliability. NASA Ames is leading the effort to advance inspection and health management technologies for thermal protection systems. This paper summarizes a joint project between NASA Ames and Korteks to develop active wireless sensors that can be embedded in the thermal protection system to monitor sub-surface temperature histories. These devices are thermocouples integrated with radio-frequency identification circuitry to enable acquisition and non-contact communication of temperature data through aerospace thermal protection materials. Two generations of prototype sensors are discussed. The advanced prototype collects data from three type-k thermocouples attached to a 2.54-cm square integrated circuit.

  7. Active pixel sensors: The sensor of choice for future space applications

    OpenAIRE

    Leijtens, J.; Theuwissen, A.; Rao, P.R.; Wang, X.; Xie, N.

    2007-01-01

    It is generally known that active pixel sensors (APS) have a number of advantages over CCD detectors if it comes to cost for mass production, power consumption and ease of integration. Nevertheless, most space applications still use CCD detectors because they tend to give better performance and have a successful heritage. To this respect a change may be at hand with the advent of deep sub-micron processed APS imagers (< 0.25-micron feature size). Measurements performed on test structures at t...

  8. Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, H. [PBI-Dansensor A/S (Denmark); Toft Soerensen, O. [Risoe National Lab., Materials Research Dept. (Denmark)

    1999-10-01

    A new type of ceramic oxygen sensors based on semiconducting oxides was developed in this project. The advantage of these sensors compared to standard ZrO{sub 2} sensors is that they do not require a reference gas and that they can be produced in small sizes. The sensor design and the techniques developed for production of these sensors are judged suitable by the participating industry for a niche production of a new generation of oxygen sensors. Materials research on new oxygen ion conducting conductors both for applications in oxygen sensors and in fuel was also performed in this project and finally a new process was developed for fabrication of ceramic tubes by dip-coating. (EHS)

  9. Activity Recognition Using Fusion of Low-Cost Sensors on a Smartphone for Mobile Navigation Application

    Directory of Open Access Journals (Sweden)

    Sara Saeedi

    2015-08-01

    Full Text Available Low-cost inertial and motion sensors embedded on smartphones have provided a new platform for dynamic activity pattern inference. In this research, a comparison has been conducted on different sensor data, feature spaces and feature selection methods to increase the efficiency and reduce the computation cost of activity recognition on the smartphones. We evaluated a variety of feature spaces and a number of classification algorithms from the area of Machine Learning, including Naive Bayes, Decision Trees, Artificial Neural Networks and Support Vector Machine classifiers. A smartphone app that performs activity recognition is being developed to collect data and send them to a server for activity recognition. Using extensive experiments, the performance of various feature spaces has been evaluated. The results showed that the Bayesian Network classifier yields recognition accuracy of 96.21% using four features while requiring fewer computations.

  10. Novel Flexible Wearable Sensor Materials and Signal Processing for Vital Sign and Human Activity Monitoring.

    Science.gov (United States)

    Servati, Amir; Zou, Liang; Wang, Z Jane; Ko, Frank; Servati, Peyman

    2017-07-13

    Advances in flexible electronic materials and smart textile, along with broad availability of smart phones, cloud and wireless systems have empowered the wearable technologies for significant impact on future of digital and personalized healthcare as well as consumer electronics. However, challenges related to lack of accuracy, reliability, high power consumption, rigid or bulky form factor and difficulty in interpretation of data have limited their wide-scale application in these potential areas. As an important solution to these challenges, we present latest advances in novel flexible electronic materials and sensors that enable comfortable and conformable body interaction and potential for invisible integration within daily apparel. Advances in novel flexible materials and sensors are described for wearable monitoring of human vital signs including, body temperature, respiratory rate and heart rate, muscle movements and activity. We then present advances in signal processing focusing on motion and noise artifact removal, data mining and aspects of sensor fusion relevant to future clinical applications of wearable technology.

  11. Towards a sensor for detecting human presence and activity

    OpenAIRE

    Benezeth , Yannick; Laurent , Hélène; Emile , Bruno; Rosenberger , Christophe

    2011-01-01

    International audience; In this paper, we propose a vision-based system for human detection and tracking in indoor environment allowing to collect higher level information on people activity. The developed presence sensor based on video analysis, using a static camera is ¯rst of all presented. Composed of three main steps, the ¯rst one consists in change detection using a background model updated at di®erent levels to manage the most common variations of the environment. A moving objects trac...

  12. Detection of Cardiopulmonary Activity and Related Abnormal Events Using Microsoft Kinect Sensor.

    Science.gov (United States)

    Al-Naji, Ali; Chahl, Javaan

    2018-03-20

    Monitoring of cardiopulmonary activity is a challenge when attempted under adverse conditions, including different sleeping postures, environmental settings, and an unclear region of interest (ROI). This study proposes an efficient remote imaging system based on a Microsoft Kinect v2 sensor for the observation of cardiopulmonary-signal-and-detection-related abnormal cardiopulmonary events (e.g., tachycardia, bradycardia, tachypnea, bradypnea, and central apnoea) in many possible sleeping postures within varying environmental settings including in total darkness and whether the subject is covered by a blanket or not. The proposed system extracts the signal from the abdominal-thoracic region where cardiopulmonary activity is most pronounced, using a real-time image sequence captured by Kinect v2 sensor. The proposed system shows promising results in any sleep posture, regardless of illumination conditions and unclear ROI even in the presence of a blanket, whilst being reliable, safe, and cost-effective.

  13. Detection of Cardiopulmonary Activity and Related Abnormal Events Using Microsoft Kinect Sensor

    Directory of Open Access Journals (Sweden)

    Ali Al-Naji

    2018-03-01

    Full Text Available Monitoring of cardiopulmonary activity is a challenge when attempted under adverse conditions, including different sleeping postures, environmental settings, and an unclear region of interest (ROI. This study proposes an efficient remote imaging system based on a Microsoft Kinect v2 sensor for the observation of cardiopulmonary-signal-and-detection-related abnormal cardiopulmonary events (e.g., tachycardia, bradycardia, tachypnea, bradypnea, and central apnoea in many possible sleeping postures within varying environmental settings including in total darkness and whether the subject is covered by a blanket or not. The proposed system extracts the signal from the abdominal-thoracic region where cardiopulmonary activity is most pronounced, using a real-time image sequence captured by Kinect v2 sensor. The proposed system shows promising results in any sleep posture, regardless of illumination conditions and unclear ROI even in the presence of a blanket, whilst being reliable, safe, and cost-effective.

  14. Design of a high-lift experiment in water including active flow control

    International Nuclear Information System (INIS)

    Beutel, T; Schwerter, M; Büttgenbach, S; Leester-Schädel, M; Sattler, S; El Sayed, Y; Radespiel, R; Zander, M; Sinapius, M; Wierach, P

    2014-01-01

    This paper describes the structural design of an active flow-control experiment. The aim of the experiment is to investigate the increase in efficiency of an internally blown Coanda flap using unsteady blowing. The system uses tailor-made microelectromechanical (MEMS) pressure sensors to determine the state of the oncoming flow and an actuated lip to regulate the mass flow and velocity of a stream near a wall over the internally blown flap. Sensors and actuators are integrated into a highly loaded system that is extremely compact. The sensors are connected to a bus system that feeds the data into a real-time control system. The piezoelectric actuators using the d 33 effect at a comparable low voltage of 120 V are integrated into a lip that controls the blowout slot height. The system is designed for closed-loop control that efficiently avoids flow separation on the Coanda flap. The setup is designed for water-tunnel experiments in order to reduce the free-stream velocity and the system’s control frequency by a factor of 10 compared with that in air. This paper outlines the function and verification of the system’s main components and their development. (technical note)

  15. A 128 x 128 CMOS Active Pixel Image Sensor for Highly Integrated Imaging Systems

    Science.gov (United States)

    Mendis, Sunetra K.; Kemeny, Sabrina E.; Fossum, Eric R.

    1993-01-01

    A new CMOS-based image sensor that is intrinsically compatible with on-chip CMOS circuitry is reported. The new CMOS active pixel image sensor achieves low noise, high sensitivity, X-Y addressability, and has simple timing requirements. The image sensor was fabricated using a 2 micrometer p-well CMOS process, and consists of a 128 x 128 array of 40 micrometer x 40 micrometer pixels. The CMOS image sensor technology enables highly integrated smart image sensors, and makes the design, incorporation and fabrication of such sensors widely accessible to the integrated circuit community.

  16. Active hydrothermal and non-active massive sulfide mound investigation using a new multiparameter chemical sensor

    Science.gov (United States)

    Han, C.; Wu, G.; Qin, H.; Wang, Z.

    2012-12-01

    Investigation of active hydrothermal mound as well as non-active massive sulfide mound are studied recently. However, there is still lack of in-situ detection method for the non-active massive sulfide mound. Even though Transient ElectroMagnetic (TEM) and Electric Self-potential (SP) methods are good, they both are labour, time and money cost work. We proposed a new multiparameter chemical sensor method to study the seafloor active hydrothermal mound as well as non-active massive sulfide mound. This sensor integrates Eh, S2- ions concentration and pH electrochemical electrodes together, and could found chemical change caused by the active hydrothermal vent, even weak chemical abnormalities by non-active massive sulfide hydrothermal mound which MARP and CTD sometimes cannot detect. In 2012, the 1st Leg of the Chinese 26th cruise, the multiparameter chemical sensor was carried out with the deepsea camera system over the Carlsberg Ridge in Indian Ocean by R/V DAYANGYIHAO. It was shown small Eh and S2- ions concentration abnormal around a site at Northwest Indian ridge. This site was also evidenced by the TV grab. In the 2nd Leg of the same cruise in June, this chemical sensor was carried out with TEM and SP survey system. The chemical abnormalities are matched very well with both TEM and SP survey results. The results show that the multiparameter chemical sensor method not only can detect active hydrothermal mound, but also can find the non-active massive sulfide hydrothermal mound.

  17. Bonding techniques for hybrid active pixel sensors (HAPS)

    Energy Technology Data Exchange (ETDEWEB)

    Bigas, M. [Centre Nacional de Microelectronica, CNM-IMB (CSIC), Campus Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)]. E-mail: Marc.Bigas@cnm.es; Cabruja, E. [Centre Nacional de Microelectronica, CNM-IMB (CSIC), Campus Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)]. E-mail: Enric.Cabruja@cnm.es; Lozano, M. [Centre Nacional de Microelectronica, CNM-IMB (CSIC), Campus Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)

    2007-05-01

    A hybrid active pixel sensor (HAPS) consists of an array of sensing elements which is connected to an electronic read-out unit. The most used way to connect these two different devices is bump bonding. This interconnection technique is very suitable for these systems because it allows a very fine pitch and a high number of I/Os. However, there are other interconnection techniques available such as direct bonding. This paper, as a continuation of a review [M. Lozano, E. Cabruja, A. Collado, J. Santander, M. Ullan, Nucl. Instr. and Meth. A 473 (1-2) (2001) 95-101] published in 2001, presents an update of the different advanced bonding techniques available for manufacturing a hybrid active pixel detector.

  18. Dealing with the Effects of Sensor Displacement in Wearable Activity Recognition

    Directory of Open Access Journals (Sweden)

    Oresti Banos

    2014-06-01

    Full Text Available Most wearable activity recognition systems assume a predefined sensor deployment that remains unchanged during runtime. However, this assumption does not reflect real-life conditions. During the normal use of such systems, users may place the sensors in a position different from the predefined sensor placement. Also, sensors may move from their original location to a different one, due to a loose attachment. Activity recognition systems trained on activity patterns characteristic of a given sensor deployment may likely fail due to sensor displacements. In this work, we innovatively explore the effects of sensor displacement induced by both the intentional misplacement of sensors and self-placement by the user. The effects of sensor displacement are analyzed for standard activity recognition techniques, as well as for an alternate robust sensor fusion method proposed in a previous work. While classical recognition models show little tolerance to sensor displacement, the proposed method is proven to have notable capabilities to assimilate the changes introduced in the sensor position due to self-placement and provides considerable improvements for large misplacements.

  19. Genetically encoded proton sensors reveal activity-dependent pH changes in neurons

    Directory of Open Access Journals (Sweden)

    Joseph Valentino Raimondo

    2012-05-01

    Full Text Available The regulation of hydrogen ion concentration (pH is fundamental to cell viability, metabolism and enzymatic function. Within the nervous system, the control of pH is also involved in diverse and dynamic processes including development, synaptic transmission and the control of network excitability. As pH affects neuronal activity, and can also itself be altered by neuronal activity, the existence of tools to accurately measure hydrogen ion fluctuations is important for understanding the role pH plays under physiological and pathological conditions. Outside of their use as a marker of synaptic release, genetically encoded pH sensors have not been utilised to study hydrogen ion fluxes associated with network activity. By combining whole-cell patch clamp with simultaneous two-photon or confocal imaging, we quantified the amplitude and time course of neuronal, intracellular, acidic transients evoked by epileptiform activity in two separate in vitro models of temporal lobe epilepsy. In doing so, we demonstrate the suitability of three genetically encoded pH sensors: deGFP4, E2GFP and Cl-sensor for investigating activity-dependent pH changes at the level of single neurons.

  20. Genetically encoded proton sensors reveal activity-dependent pH changes in neurons.

    Science.gov (United States)

    Raimondo, Joseph V; Irkle, Agnese; Wefelmeyer, Winnie; Newey, Sarah E; Akerman, Colin J

    2012-01-01

    The regulation of hydrogen ion concentration (pH) is fundamental to cell viability, metabolism, and enzymatic function. Within the nervous system, the control of pH is also involved in diverse and dynamic processes including development, synaptic transmission, and the control of network excitability. As pH affects neuronal activity, and can also itself be altered by neuronal activity, the existence of tools to accurately measure hydrogen ion fluctuations is important for understanding the role pH plays under physiological and pathological conditions. Outside of their use as a marker of synaptic release, genetically encoded pH sensors have not been utilized to study hydrogen ion fluxes associated with network activity. By combining whole-cell patch clamp with simultaneous two-photon or confocal imaging, we quantified the amplitude and time course of neuronal, intracellular, acidic transients evoked by epileptiform activity in two separate in vitro models of temporal lobe epilepsy. In doing so, we demonstrate the suitability of three genetically encoded pH sensors: deGFP4, E(2)GFP, and Cl-sensor for investigating activity-dependent pH changes at the level of single neurons.

  1. A multi-sensor monitoring system of human physiology and daily activities.

    Science.gov (United States)

    Doherty, Sean T; Oh, Paul

    2012-04-01

    To present the design and pilot test results of a continuous multi-sensor monitoring system of real-world physiological conditions and daily life (activities, travel, exercise, and food consumption), culminating in a Web-based graphical decision-support interface. The system includes a set of wearable sensors wirelessly connected to a "smartphone" with a continuously running software application that compresses and transmits the data to a central server. Sensors include a Global Positioning System (GPS) receiver, electrocardiogram (ECG), three-axis accelerometer, and continuous blood glucose monitor. A food/medicine diary and prompted recall activity diary were also used. The pilot test involved 40 type 2 diabetic patients monitored over a 72-h period. All but three subjects were successfully monitored for the full study period. Smartphones proved to be an effective hub for managing multiple streams of data but required attention to data compression and battery consumption issues. ECG, accelerometer, and blood glucose devices performed adequately as long as subjects wore them. GPS tracking for a full day was feasible, although significant efforts are needed to impute missing data. Activity detection algorithms were successful in identifying activities and trip modes but could benefit by incorporating accelerometer data. The prompted recall diary was an effective tool for augmenting algorithm results, although subjects reported some difficulties with it. The food and medicine diary was completed fully, although end times and medicine dosages were occasionally missing. The unique combination of sensors holds promise for increasing accuracy and reducing burden associated with collecting individual-level activity and physiological data under real-world conditions, but significant data processing issues remain. Such data will provide new opportunities to explore the impacts of human geography and daily lifestyle on health at a fine spatial/temporal scale.

  2. Active design method for the static characteristics of a piezoelectric six-axis force/torque sensor.

    Science.gov (United States)

    Liu, Jun; Li, Min; Qin, Lan; Liu, Jingcheng

    2014-01-02

    To address the bottleneck issues of an elastic-style six-axis force/torque sensor (six-axis force sensor), this work proposes a no-elastic piezoelectric six-axis force sensor. The operating principle of the piezoelectric six-axis force sensor is analyzed, and a structural model is constructed. The static-active design theory of the piezoelectric six-axis force sensor is established, including a static analytical/mathematical model and numerical simulation model (finite element model). A piezoelectric six-axis force sensor experimental prototype is developed according to the analytical mathematical model and numerical simulation model, and selected static characteristic parameters (including sensitivity, isotropic degree and cross-coupling) are tested using this model with three approaches. The measured results are in agreement with the analytical results from the static-active design method. Therefore, this study has successfully established a foundation for further research into the piezoelectric multi-axis force sensor and an overall design approach based on static characteristics.

  3. CMOS VLSI Active-Pixel Sensor for Tracking

    Science.gov (United States)

    Pain, Bedabrata; Sun, Chao; Yang, Guang; Heynssens, Julie

    2004-01-01

    An architecture for a proposed active-pixel sensor (APS) and a design to implement the architecture in a complementary metal oxide semiconductor (CMOS) very-large-scale integrated (VLSI) circuit provide for some advanced features that are expected to be especially desirable for tracking pointlike features of stars. The architecture would also make this APS suitable for robotic- vision and general pointing and tracking applications. CMOS imagers in general are well suited for pointing and tracking because they can be configured for random access to selected pixels and to provide readout from windows of interest within their fields of view. However, until now, the architectures of CMOS imagers have not supported multiwindow operation or low-noise data collection. Moreover, smearing and motion artifacts in collected images have made prior CMOS imagers unsuitable for tracking applications. The proposed CMOS imager (see figure) would include an array of 1,024 by 1,024 pixels containing high-performance photodiode-based APS circuitry. The pixel pitch would be 9 m. The operations of the pixel circuits would be sequenced and otherwise controlled by an on-chip timing and control block, which would enable the collection of image data, during a single frame period, from either the full frame (that is, all 1,024 1,024 pixels) or from within as many as 8 different arbitrarily placed windows as large as 8 by 8 pixels each. A typical prior CMOS APS operates in a row-at-a-time ( grolling-shutter h) readout mode, which gives rise to exposure skew. In contrast, the proposed APS would operate in a sample-first/readlater mode, suppressing rolling-shutter effects. In this mode, the analog readout signals from the pixels corresponding to the windows of the interest (which windows, in the star-tracking application, would presumably contain guide stars) would be sampled rapidly by routing them through a programmable diagonal switch array to an on-chip parallel analog memory array. The

  4. Sensor to detect endothelialization on an active coronary stent

    Directory of Open Access Journals (Sweden)

    Coffey Arthur C

    2010-11-01

    Full Text Available Abstract Background A serious complication with drug-eluting coronary stents is late thrombosis, caused by exposed stent struts not covered by endothelial cells in the healing process. Real-time detection of this healing process could guide physicians for more individualized anti-platelet therapy. Here we present work towards developing a sensor to detect this healing process. Sensors on several stent struts could give information about the heterogeneity of healing across the stent. Methods A piezoelectric microcantilever was insulated with parylene and demonstrated as an endothelialization detector for incorporation within an active coronary stent. After initial characterization, endothelial cells were plated onto the cantilever surface. After they attached to the surface, they caused an increase in mass, and thus a decrease in the resonant frequencies of the cantilever. This shift was then detected electrically with an LCR meter. The self-sensing, self-actuating cantilever does not require an external, optical detection system, thus allowing for implanted applications. Results A cell density of 1300 cells/mm2 on the cantilever surface is detected. Conclusions We have developed a self-actuating, self-sensing device for detecting the presence of endothelial cells on a surface. The device is biocompatible and functions reliably in ionic liquids, making it appropriate for implantable applications. This sensor can be placed along the struts of a coronary stent to detect when the struts have been covered with a layer of endothelial cells and are no longer available surfaces for clot formation. Anti-platelet therapy can be adjusted in real-time with respect to a patient's level of healing and hemorrhaging risks.

  5. CMOS monolithic active pixel sensors for high energy physics

    Energy Technology Data Exchange (ETDEWEB)

    Snoeys, W., E-mail: walter.snoeys@cern.ch

    2014-11-21

    Monolithic pixel detectors integrating sensor matrix and readout in one piece of silicon are only now starting to make their way into high energy physics. Two major requirements are radiation tolerance and low power consumption. For the most extreme radiation levels, signal charge has to be collected by drift from a depletion layer onto a designated collection electrode without losing the signal charge elsewhere in the in-pixel circuit. Low power consumption requires an optimization of Q/C, the ratio of the collected signal charge over the input capacitance [1]. Some solutions to combine sufficient Q/C and collection by drift require exotic fabrication steps. More conventional solutions up to now require a simple in-pixel readout circuit. Both high voltage CMOS technologies and Monolithic Active Pixel Sensors (MAPS) technologies with high resistivity epitaxial layers offer high voltage diodes. The choice between the two is not fundamental but more a question of how much depletion can be reached and also of availability and cost. This paper tries to give an overview.

  6. CMOS Active-Pixel Image Sensor With Intensity-Driven Readout

    Science.gov (United States)

    Langenbacher, Harry T.; Fossum, Eric R.; Kemeny, Sabrina

    1996-01-01

    Proposed complementary metal oxide/semiconductor (CMOS) integrated-circuit image sensor automatically provides readouts from pixels in order of decreasing illumination intensity. Sensor operated in integration mode. Particularly useful in number of image-sensing tasks, including diffractive laser range-finding, three-dimensional imaging, event-driven readout of sparse sensor arrays, and star tracking.

  7. A micro-fabricated force sensor using an all thin film piezoelectric active sensor.

    Science.gov (United States)

    Lee, Junwoo; Choi, Wook; Yoo, Yong Kyoung; Hwang, Kyo Seon; Lee, Sang-Myung; Kang, Sungchul; Kim, Jinseok; Lee, Jeong Hoon

    2014-11-25

    The ability to measure pressure and force is essential in biomedical applications such as minimally invasive surgery (MIS) and palpation for detecting cancer cysts. Here, we report a force sensor for measuring a shear and normal force by combining an arrayed piezoelectric sensors layer with a precut glass top plate connected by four stress concentrating legs. We designed and fabricated a thin film piezoelectric force sensor and proposed an enhanced sensing tool to be used for analyzing gentle touches without the external voltage source used in FET sensors. Both the linear sensor response from 3 kPa to 30 kPa and the exact signal responses from the moving direction illustrate the strong feasibility of the described thin film miniaturized piezoelectric force sensor.

  8. A Micro-Fabricated Force Sensor Using an All Thin Film Piezoelectric Active Sensor

    Directory of Open Access Journals (Sweden)

    Junwoo Lee

    2014-11-01

    Full Text Available The ability to measure pressure and force is essential in biomedical applications such as minimally invasive surgery (MIS and palpation for detecting cancer cysts. Here, we report a force sensor for measuring a shear and normal force by combining an arrayed piezoelectric sensors layer with a precut glass top plate connected by four stress concentrating legs. We designed and fabricated a thin film piezoelectric force sensor and proposed an enhanced sensing tool to be used for analyzing gentle touches without the external voltage source used in FET sensors. Both the linear sensor response from 3 kPa to 30 kPa and the exact signal responses from the moving direction illustrate the strong feasibility of the described thin film miniaturized piezoelectric force sensor.

  9. Radiation hardness of CMOS monolithic active pixel sensors manufactured in a 0.18 μm CMOS process

    Energy Technology Data Exchange (ETDEWEB)

    Linnik, Benjamin [Goethe-Universitaet Frankfurt (Germany); Collaboration: CBM-MVD-Collaboration

    2015-07-01

    CMOS Monolithic Active Pixels Sensors (MAPS) are considered as the technology of choice for various vertex detectors in particle and heavy-ion physics including the STAR HFT, the upgrade of the ALICE ITS, the future ILC detectors and the CBM experiment at FAIR. To match the requirements of those detectors, their hardness to radiation is being improved, among others in a joined research activity of the Goethe University Frankfurt and the IPHC Strasbourg. It was assumed that combining an improved high resistivity (1-8 kΩcm) sensitive medium with the features of a 0.18 μm CMOS process, is suited to reach substantial improvements in terms of radiation hardness as compared to earlier sensor designs. This strategy was tested with a novel generation of sensor prototypes named MIMOSA-32 and MIMOSA-34. We show results on the radiation hardness of those sensors and discuss its impact on the design of future vertex detectors.

  10. Planar optical waveguide based sandwich assay sensors and processes for the detection of biological targets including protein markers, pathogens and cellular debris

    Science.gov (United States)

    Martinez, Jennifer S [Santa Fe, NM; Swanson, Basil I [Los Alamos, NM; Grace, Karen M [Los Alamos, NM; Grace, Wynne K [Los Alamos, NM; Shreve, Andrew P [Santa Fe, NM

    2009-06-02

    An assay element is described including recognition ligands bound to a film on a single mode planar optical waveguide, the film from the group of a membrane, a polymerized bilayer membrane, and a self-assembled monolayer containing polyethylene glycol or polypropylene glycol groups therein and an assay process for detecting the presence of a biological target is described including injecting a biological target-containing sample into a sensor cell including the assay element, with the recognition ligands adapted for binding to selected biological targets, maintaining the sample within the sensor cell for time sufficient for binding to occur between selected biological targets within the sample and the recognition ligands, injecting a solution including a reporter ligand into the sensor cell; and, interrogating the sample within the sensor cell with excitation light from the waveguide, the excitation light provided by an evanescent field of the single mode penetrating into the biological target-containing sample to a distance of less than about 200 nanometers from the waveguide thereby exciting the fluorescent-label in any bound reporter ligand within a distance of less than about 200 nanometers from the waveguide and resulting in a detectable signal.

  11. A Single-Transistor Active Pixel CMOS Image Sensor Architecture

    International Nuclear Information System (INIS)

    Zhang Guo-An; He Jin; Zhang Dong-Wei; Su Yan-Mei; Wang Cheng; Chen Qin; Liang Hai-Lang; Ye Yun

    2012-01-01

    A single-transistor CMOS active pixel image sensor (1 T CMOS APS) architecture is proposed. By switching the photosensing pinned diode, resetting and selecting can be achieved by diode pull-up and capacitive coupling pull-down of the source follower. Thus, the reset and selected transistors can be removed. In addition, the reset and selected signal lines can be shared to reduce the metal signal line, leading to a very high fill factor. The pixel design and operation principles are discussed in detail. The functionality of the proposed 1T CMOS APS architecture has been experimentally verified using a fabricated chip in a standard 0.35 μm CMOS AMIS technology

  12. Development of Smart Active Layer Sensor (I) : Theory and Concept Study

    International Nuclear Information System (INIS)

    Yoon, Dong Jin; Lee, Young Sup; Kwon, Jae Hwa; Lee, Sang Il

    2004-01-01

    This paper is the first part of the study on the development of a smart active layer (SAL) sensor, which consists of two parts. In this first part, the theory and concept of the SAL sensor is investigated, which is designed for the detection of elastic waves caused by internal cracks and damages in structures. For the development SAL sensor, (i) the basic theory of elastic waves was studied, (ii) the feasible study of the SAL as an elastic waves detection sensor using the finite element analysis (FEA) with respect to a piezoceramic disc was performed. (iii) the comparison of performances between some piezoceramic sensors and a commercial acoustic emission (AE) sensor was accomplished to ensure the applicability by the experimental means, such as a pencil lead break test. Also, the conceptional study for the SAL sensor, which can be utilized for the effective detection and locating of defects by the arrangement of regularly distributed sensors, was discussed

  13. 7 CFR 981.441 - Credit for market promotion activities, including paid advertising.

    Science.gov (United States)

    2010-01-01

    ... promotion activities, including paid advertising. (a) In order for a handler to receive credit for his/her... 7 Agriculture 8 2010-01-01 2010-01-01 false Credit for market promotion activities, including paid advertising. 981.441 Section 981.441 Agriculture Regulations of the Department of Agriculture (Continued...

  14. Wearable motion sensors to continuously measure real-world physical activities.

    Science.gov (United States)

    Dobkin, Bruce H

    2013-12-01

    Rehabilitation for sensorimotor impairments aims to improve daily activities, walking, exercise, and motor skills. Monitoring of practice and measuring outcomes, however, is usually restricted to laboratory-based procedures and self-reports. Mobile health devices may reverse these confounders of daily care and research trials. Wearable, wireless motion sensor data, analyzed by activity pattern-recognition algorithms, can describe the type, quantity, and quality of mobility-related activities in the community. Data transmission from the sensors to a cell phone and the Internet enable continuous monitoring. Remote access to laboratory quality data about walking speed, duration and distance, gait asymmetry and smoothness of movements, as well as cycling, exercise, and skills practice, opens new opportunities to engage patients in progressive, personalized therapies with feedback about the performance. Clinical trial designs will be able to include remote verification of the integrity of complex physical interventions and compliance with practice, as well as capture repeated, ecologically sound, ratio scale outcome measures. Given the progressively falling cost of miniaturized wearable gyroscopes, accelerometers, and other physiologic sensors, as well as inexpensive data transmission, sensing systems may become as ubiquitous as cell phones for healthcare. Neurorehabilitation can develop these mobile health platforms for daily care and clinical trials to improve exercise and fitness, skills learning, and physical functioning.

  15. Vector disparity sensor with vergence control for active vision systems.

    Science.gov (United States)

    Barranco, Francisco; Diaz, Javier; Gibaldi, Agostino; Sabatini, Silvio P; Ros, Eduardo

    2012-01-01

    This paper presents an architecture for computing vector disparity for active vision systems as used on robotics applications. The control of the vergence angle of a binocular system allows us to efficiently explore dynamic environments, but requires a generalization of the disparity computation with respect to a static camera setup, where the disparity is strictly 1-D after the image rectification. The interaction between vision and motor control allows us to develop an active sensor that achieves high accuracy of the disparity computation around the fixation point, and fast reaction time for the vergence control. In this contribution, we address the development of a real-time architecture for vector disparity computation using an FPGA device. We implement the disparity unit and the control module for vergence, version, and tilt to determine the fixation point. In addition, two on-chip different alternatives for the vector disparity engines are discussed based on the luminance (gradient-based) and phase information of the binocular images. The multiscale versions of these engines are able to estimate the vector disparity up to 32 fps on VGA resolution images with very good accuracy as shown using benchmark sequences with known ground-truth. The performances in terms of frame-rate, resource utilization, and accuracy of the presented approaches are discussed. On the basis of these results, our study indicates that the gradient-based approach leads to the best trade-off choice for the integration with the active vision system.

  16. Validation and User Evaluation of a Sensor-Based Method for Detecting Mobility-Related Activities in Older Adults.

    Directory of Open Access Journals (Sweden)

    Hilde A E Geraedts

    Full Text Available Regular physical activity is essential for older adults to stay healthy and independent. However, daily physical activity is generally low among older adults and mainly consists of activities such as standing and shuffling around indoors. Accurate measurement of this low-energy expenditure daily physical activity is crucial for stimulation of activity. The objective of this study was to assess the validity of a necklace-worn sensor-based method for detecting time-on-legs and daily life mobility related postures in older adults. In addition user opinion about the practical use of the sensor was evaluated. Twenty frail and non-frail older adults performed a standardized and free movement protocol in their own home. Results of the sensor-based method were compared to video observation. Sensitivity, specificity and overall agreement of sensor outcomes compared to video observation were calculated. Mobility was assessed based on time-on-legs. Further assessment included the categories standing, sitting, walking and lying. Time-on-legs based sensitivity, specificity and percentage agreement were good to excellent and comparable to laboratory outcomes in other studies. Category-based sensitivity, specificity and overall agreement were moderate to excellent. The necklace-worn sensor is considered an acceptable valid instrument for assessing home-based physical activity based upon time-on-legs in frail and non-frail older adults, but category-based assessment of gait and postures could be further developed.

  17. E-Beam Effects on CMOS Active Pixel Sensors

    International Nuclear Information System (INIS)

    Kang, Dong Ook; Jo, Gyu Seong; Kim, Hyeon Daek; Kim, Hyunk Taek; Kim, Jong Yeol; Kim, Chan Kyu

    2011-01-01

    Three different CMOS active pixel structures manufactured in a deep submicron process have been evaluated with electron beam. The devices were exposed to 1 MeV electron beam up to 5kGy. Dark current increased after E-beam irradiation differently at each pixel structure. Dark current change is dependent on CMOS pixel structures. CMOS image sensors are now good candidates in demanding applications such as medical image sensor, particle detection and space remote sensing. In these situations, CISs are exposed to high doses of radiation. In fact radiation is known to generate trapped charge in CMOS oxides. It can lead to threshold voltage shifts and current leakages in MOSFETs and dark current increase in photodiodes. We studied ionizing effects in three types of CMOS APSs fabricated by 0.25 CMOS process. The devices were irradiated by a Co 60 source up to 50kGy. All irradiation took place at room temperature. The dark current in the three different pixels exhibits increase with electron beam exposure. From the above figure, the change of dark current is dependent on the pixel structure. Double junction structure has shown relatively small increase of dark current after electron beam irradiation. The dark current in the three different pixels exhibits increase with electron beam exposure. The contribution of the total ionizing dose to the dark current increase is small here, since the devices were left unbiased during the electron beam irradiation. Radiation hardness in dependent on the pixel structures. Pixel2 is relatively vulnerable to radiation exposure. Pixel3 has radiation hardened structure

  18. Active pixel sensor array as a detector for electron microscopy.

    Science.gov (United States)

    Milazzo, Anna-Clare; Leblanc, Philippe; Duttweiler, Fred; Jin, Liang; Bouwer, James C; Peltier, Steve; Ellisman, Mark; Bieser, Fred; Matis, Howard S; Wieman, Howard; Denes, Peter; Kleinfelder, Stuart; Xuong, Nguyen-Huu

    2005-09-01

    A new high-resolution recording device for transmission electron microscopy (TEM) is urgently needed. Neither film nor CCD cameras are systems that allow for efficient 3-D high-resolution particle reconstruction. We tested an active pixel sensor (APS) array as a replacement device at 200, 300, and 400 keV using a JEOL JEM-2000 FX II and a JEM-4000 EX electron microscope. For this experiment, we used an APS prototype with an area of 64 x 64 pixels of 20 microm x 20 microm pixel pitch. Single-electron events were measured by using very low beam intensity. The histogram of the incident electron energy deposited in the sensor shows a Landau distribution at low energies, as well as unexpected events at higher absorbed energies. After careful study, we concluded that backscattering in the silicon substrate and re-entering the sensitive epitaxial layer a second time with much lower speed caused the unexpected events. Exhaustive simulation experiments confirmed the existence of these back-scattered electrons. For the APS to be usable, the back-scattered electron events must be eliminated, perhaps by thinning the substrate to less than 30 microm. By using experimental data taken with an APS chip with a standard silicon substrate (300 microm) and adjusting the results to take into account the effect of a thinned silicon substrate (30 microm), we found an estimate of the signal-to-noise ratio for a back-thinned detector in the energy range of 200-400 keV was about 10:1 and an estimate for the spatial resolution was about 10 microm.

  19. Active pixel sensors: the sensor of choice for future space applications?

    Science.gov (United States)

    Leijtens, Johan; Theuwissen, Albert; Rao, Padmakumar R.; Wang, Xinyang; Xie, Ning

    2007-10-01

    It is generally known that active pixel sensors (APS) have a number of advantages over CCD detectors if it comes to cost for mass production, power consumption and ease of integration. Nevertheless, most space applications still use CCD detectors because they tend to give better performance and have a successful heritage. To this respect a change may be at hand with the advent of deep sub-micron processed APS imagers (< 0.25-micron feature size). Measurements performed on test structures at the University of Delft have shown that the imagers are very radiation tolerant even if made in a standard process without the use of special design rules. Furthermore it was shown that the 1/f noise associated with deep sub-micron imagers is reduced as compared to previous generations APS imagers due to the improved quality of the gate oxides. Considering that end of life performance will have to be guaranteed, limited budget for adding shielding metal will be available for most applications and lower power operations is always seen as a positive characteristic in space applications, deep sub-micron APS imagers seem to have a number of advantages over CCD's that will probably cause them to replace CCD's in those applications where radiation tolerance and low power operation are important

  20. Solid electrolyte gas sensors based on cyclic voltammetry with one active electrode

    Energy Technology Data Exchange (ETDEWEB)

    Jasinski, G; Jasinski, P, E-mail: gregor@biomed.eti.pg.gda.pl [Gdansk University of Technology, Faculty of Electronics, Telecommunication and Informatics, Narutowicza 11/12, 80-233 Gdansk (Poland)

    2011-10-29

    Solid state gas sensors are cost effective, small, rugged and reliable. Typically electrochemical solid state sensors operate in either potentiometric or amperometric mode. However, a lack of selectivity is sometimes a shortcoming of such sensors. It seems that improvements of selectivity can be obtained in case of the electrocatalytic sensors, which operate in cyclic voltammetry mode. Their working principle is based on acquisition of an electric current, while voltage ramp is applied to the sensor. The current-voltage response depends in a unique way on the type and concentration of ambient gas. Most electrocatalytic sensors have symmetrical structure. They are in a form of pellets with two electrodes placed on their opposite sides. Electrochemical reactions occur simultaneously on both electrodes. In this paper results for sensors with only one active electrode exposed to ambient gas are presented. The other electrode was isolated from ambient gas with dielectric sealing. This sensor construction allows application of advanced measuring procedures, which permit sensor regeneration acceleration. Experiments were conducted on Nasicon sensors. Properties of two sensors, one with one active electrode and second with symmetrical structure, used for the detection of mixtures of NO{sub 2} and synthetic air are compared.

  1. Toward real time detection of the basic living activity in home using a wearable sensor and smart home sensors.

    Science.gov (United States)

    Bang, Sunlee; Kim, Minho; Song, Sa-Kwang; Park, Soo-Jun

    2008-01-01

    As the elderly people living alone are enormously increasing recently, we need the system inferring activities of daily living (ADL) for maintaining healthy life and recognizing emergency. The system should be constructed with sensors, which are used to associate with people's living while remaining as non intrusive views as possible. To do this, the proposed system use a triaxial accelerometer sensor and environment sensors indicating contact with subject in home. Particularly, in order to robustly infer ADLs, we present component ADL, which is decided with conjunction of human motion together, not just only contacted object identification. It is an important component in inferring ADL. In special, component ADL decision firstly refines misclassified initial activities, which improves the accuracy of recognizing ADL. Preliminary experiments results for proposed system provides overall recognition rate of over 97% over 8 component ADLs, which can be effectively applicable to recognize the final ADLs.

  2. Recognizing Multi-user Activities using Wearable Sensors in a Smart Home

    DEFF Research Database (Denmark)

    Wang, Liang; Gu, Tao; Tao, Xianping

    2010-01-01

    The advances of wearable sensors and wireless networks oer many opportunities to recognize human activities from sensor readings in pervasive computing. Existing work so far focuses mainly on recognizing activities of a single user in a home environment. However, there are typically multiple inha...

  3. A Hierarchical Approach to Real-time Activity Recognition in Body Sensor Networks

    DEFF Research Database (Denmark)

    Wang, Liang; Gu, Tao; Tao, Xianping

    2012-01-01

    Real-time activity recognition in body sensor networks is an important and challenging task. In this paper, we propose a real-time, hierarchical model to recognize both simple gestures and complex activities using a wireless body sensor network. In this model, we rst use a fast and lightweight al...

  4. 77 FR 52317 - Record of Decision for Surveillance Towed Array Sensor System Low Frequency Active Sonar

    Science.gov (United States)

    2012-08-29

    ... DEPARTMENT OF DEFENSE Department of the Navy Record of Decision for Surveillance Towed Array Sensor System Low Frequency Active Sonar AGENCY: Department of the Navy, DoD. ACTION: Notice of decision... to employ up to four Surveillance Towed Array Sensor System Low Frequency Active (SURTASS LFA) sonar...

  5. Using Spread Spectrum Transform for Fast and Robust Simultaneous Measurement in Active Sensors with Multiple Emitters

    DEFF Research Database (Denmark)

    Harbo, Anders La-Cour; Stoustrup, Jakob

    2002-01-01

    We present a signal processing algorithm for making robust and simultaneous measurements in an active sensor, which has one or more emitters and a receiver, and which employs some sort of signal processing hardware. Robustness means low sensitivity to time and frequency localized disturbances......-cost active sensors....

  6. Real-time Human Activity Recognition using a Body Sensor Network

    DEFF Research Database (Denmark)

    Wang, Liang; Gu, Tao; Chen, Hanhua

    2010-01-01

    Real-time activity recognition using body sensor networks is an important and challenging task and it has many potential applications. In this paper, we propose a realtime, hierarchical model to recognize both simple gestures and complex activities using a wireless body sensor network. In this mo...

  7. Complex Human Activity Recognition Using Smartphone and Wrist-Worn Motion Sensors

    NARCIS (Netherlands)

    Shoaib, M.; Bosch, S.; Durmaz, O.; Scholten, Johan; Havinga, Paul J.M.

    2016-01-01

    The position of on-body motion sensors plays an important role in human activity recognition. Most often, mobile phone sensors at the trouser pocket or an equivalent position are used for this purpose. However, this position is not suitable for recognizing activities that involve hand gestures, such

  8. Wearable Sensor Data Classification for Human Activity Recognition Based on an Iterative Learning Framework

    Directory of Open Access Journals (Sweden)

    Juan Carlos Davila

    2017-06-01

    Full Text Available The design of multiple human activity recognition applications in areas such as healthcare, sports and safety relies on wearable sensor technologies. However, when making decisions based on the data acquired by such sensors in practical situations, several factors related to sensor data alignment, data losses, and noise, among other experimental constraints, deteriorate data quality and model accuracy. To tackle these issues, this paper presents a data-driven iterative learning framework to classify human locomotion activities such as walk, stand, lie, and sit, extracted from the Opportunity dataset. Data acquired by twelve 3-axial acceleration sensors and seven inertial measurement units are initially de-noised using a two-stage consecutive filtering approach combining a band-pass Finite Impulse Response (FIR and a wavelet filter. A series of statistical parameters are extracted from the kinematical features, including the principal components and singular value decomposition of roll, pitch, yaw and the norm of the axial components. The novel interactive learning procedure is then applied in order to minimize the number of samples required to classify human locomotion activities. Only those samples that are most distant from the centroids of data clusters, according to a measure presented in the paper, are selected as candidates for the training dataset. The newly built dataset is then used to train an SVM multi-class classifier. The latter will produce the lowest prediction error. The proposed learning framework ensures a high level of robustness to variations in the quality of input data, while only using a much lower number of training samples and therefore a much shorter training time, which is an important consideration given the large size of the dataset.

  9. Wearable Sensor Data Classification for Human Activity Recognition Based on an Iterative Learning Framework.

    Science.gov (United States)

    Davila, Juan Carlos; Cretu, Ana-Maria; Zaremba, Marek

    2017-06-07

    The design of multiple human activity recognition applications in areas such as healthcare, sports and safety relies on wearable sensor technologies. However, when making decisions based on the data acquired by such sensors in practical situations, several factors related to sensor data alignment, data losses, and noise, among other experimental constraints, deteriorate data quality and model accuracy. To tackle these issues, this paper presents a data-driven iterative learning framework to classify human locomotion activities such as walk, stand, lie, and sit, extracted from the Opportunity dataset. Data acquired by twelve 3-axial acceleration sensors and seven inertial measurement units are initially de-noised using a two-stage consecutive filtering approach combining a band-pass Finite Impulse Response (FIR) and a wavelet filter. A series of statistical parameters are extracted from the kinematical features, including the principal components and singular value decomposition of roll, pitch, yaw and the norm of the axial components. The novel interactive learning procedure is then applied in order to minimize the number of samples required to classify human locomotion activities. Only those samples that are most distant from the centroids of data clusters, according to a measure presented in the paper, are selected as candidates for the training dataset. The newly built dataset is then used to train an SVM multi-class classifier. The latter will produce the lowest prediction error. The proposed learning framework ensures a high level of robustness to variations in the quality of input data, while only using a much lower number of training samples and therefore a much shorter training time, which is an important consideration given the large size of the dataset.

  10. First tests of a novel radiation hard CMOS sensor process for Depleted Monolithic Active Pixel Sensors

    Science.gov (United States)

    Pernegger, H.; Bates, R.; Buttar, C.; Dalla, M.; van Hoorne, J. W.; Kugathasan, T.; Maneuski, D.; Musa, L.; Riedler, P.; Riegel, C.; Sbarra, C.; Schaefer, D.; Schioppa, E. J.; Snoeys, W.

    2017-06-01

    The upgrade of the ATLAS [1] tracking detector for the High-Luminosity Large Hadron Collider (LHC) at CERN requires novel radiation hard silicon sensor technologies. Significant effort has been put into the development of monolithic CMOS sensors but it has been a challenge to combine a low capacitance of the sensing node with full depletion of the sensitive layer. Low capacitance brings low analog power. Depletion of the sensitive layer causes the signal charge to be collected by drift sufficiently fast to separate hits from consecutive bunch crossings (25 ns at the LHC) and to avoid losing the charge by trapping. This paper focuses on the characterization of charge collection properties and detection efficiency of prototype sensors originally designed in the framework of the ALICE Inner Tracking System (ITS) upgrade [2]. The prototypes are fabricated both in the standard TowerJazz 180nm CMOS imager process [3] and in an innovative modification of this process developed in collaboration with the foundry, aimed to fully deplete the sensitive epitaxial layer and enhance the tolerance to non-ionizing energy loss. Sensors fabricated in standard and modified process variants were characterized using radioactive sources, focused X-ray beam and test beams before and after irradiation. Contrary to sensors manufactured in the standard process, sensors from the modified process remain fully functional even after a dose of 1015neq/cm2, which is the the expected NIEL radiation fluence for the outer pixel layers in the future ATLAS Inner Tracker (ITk) [4].

  11. Human movement activity classification approaches that use wearable sensors and mobile devices

    Science.gov (United States)

    Kaghyan, Sahak; Sarukhanyan, Hakob; Akopian, David

    2013-03-01

    Cell phones and other mobile devices become part of human culture and change activity and lifestyle patterns. Mobile phone technology continuously evolves and incorporates more and more sensors for enabling advanced applications. Latest generations of smart phones incorporate GPS and WLAN location finding modules, vision cameras, microphones, accelerometers, temperature sensors etc. The availability of these sensors in mass-market communication devices creates exciting new opportunities for data mining applications. Particularly healthcare applications exploiting build-in sensors are very promising. This paper reviews different approaches of human activity recognition.

  12. Macroenvironmental factors including GDP per capita and physical activity in Europe.

    Science.gov (United States)

    Cameron, Adrian J; Van Stralen, Maartje M; Kunst, Anton E; Te Velde, Saskia J; Van Lenthe, Frank J; Salmon, Jo; Brug, Johannes

    2013-02-01

    Socioeconomic inequalities in physical activity at the individual level are well reported. Whether inequalities in economic development and other macroenvironmental variables between countries are also related to physical activity at the country level is comparatively unstudied. We examined the relationship between country-level data on macroenvironmental factors (gross domestic product (GDP) per capita, public sector expenditure on health, percentage living in urban areas, and cars per 1000 population) with country-level physical activity prevalence obtained from previous pan-European studies. Studies that assessed leisuretime physical activity (n = 3 studies including 27 countries in adults, n = 2 studies including 28 countries in children) and total physical activity (n = 3 studies in adults including 16 countries) were analyzed separately as were studies among adults and children. Strong and consistent positive correlations were observed between country prevalence of leisure-time physical activity and country GDP per capita in adults (average r = 0.70; all studies, P G 0.05). In multivariate analysis, country prevalence of leisure-time physical activity among adults remained associated with country GDP per capita (two of three studies) but not urbanization or educational attainment. Among school-age populations, no association was found between country GDP per capita and country prevalence of leisure-time physical activity. In those studies that assessed total physical activity (which also includes occupational and transport physical activity), no association with country GDP per capita was observed. Clear differences in national leisure-time physical activity levels throughout Europe may be a consequence of economic development. Lack of economic development of some countries in Europe may make increasing leisure-time physical activity more difficult. Further examination of the link between country GDP per capita and national physical activity levels (across

  13. Multi-Sensor Fusion for Enhanced Contextual Awareness of Everyday Activities with Ubiquitous Devices

    Directory of Open Access Journals (Sweden)

    John J. Guiry

    2014-03-01

    Full Text Available In this paper, the authors investigate the role that smart devices, including smartphones and smartwatches, can play in identifying activities of daily living. A feasibility study involving N = 10 participants was carried out to evaluate the devices’ ability to differentiate between nine everyday activities. The activities examined include walking, running, cycling, standing, sitting, elevator ascents, elevator descents, stair ascents and stair descents. The authors also evaluated the ability of these devices to differentiate indoors from outdoors, with the aim of enhancing contextual awareness. Data from this study was used to train and test five well known machine learning algorithms: C4.5, CART, Naïve Bayes, Multi-Layer Perceptrons and finally Support Vector Machines. Both single and multi-sensor approaches were examined to better understand the role each sensor in the device can play in unobtrusive activity recognition. The authors found overall results to be promising, with some models correctly classifying up to 100% of all instances.

  14. A Depth Video Sensor-Based Life-Logging Human Activity Recognition System for Elderly Care in Smart Indoor Environments

    Directory of Open Access Journals (Sweden)

    Ahmad Jalal

    2014-07-01

    Full Text Available Recent advancements in depth video sensors technologies have made human activity recognition (HAR realizable for elderly monitoring applications. Although conventional HAR utilizes RGB video sensors, HAR could be greatly improved with depth video sensors which produce depth or distance information. In this paper, a depth-based life logging HAR system is designed to recognize the daily activities of elderly people and turn these environments into an intelligent living space. Initially, a depth imaging sensor is used to capture depth silhouettes. Based on these silhouettes, human skeletons with joint information are produced which are further used for activity recognition and generating their life logs. The life-logging system is divided into two processes. Firstly, the training system includes data collection using a depth camera, feature extraction and training for each activity via Hidden Markov Models. Secondly, after training, the recognition engine starts to recognize the learned activities and produces life logs. The system was evaluated using life logging features against principal component and independent component features and achieved satisfactory recognition rates against the conventional approaches. Experiments conducted on the smart indoor activity datasets and the MSRDailyActivity3D dataset show promising results. The proposed system is directly applicable to any elderly monitoring system, such as monitoring healthcare problems for elderly people, or examining the indoor activities of people at home, office or hospital.

  15. A depth video sensor-based life-logging human activity recognition system for elderly care in smart indoor environments.

    Science.gov (United States)

    Jalal, Ahmad; Kamal, Shaharyar; Kim, Daijin

    2014-07-02

    Recent advancements in depth video sensors technologies have made human activity recognition (HAR) realizable for elderly monitoring applications. Although conventional HAR utilizes RGB video sensors, HAR could be greatly improved with depth video sensors which produce depth or distance information. In this paper, a depth-based life logging HAR system is designed to recognize the daily activities of elderly people and turn these environments into an intelligent living space. Initially, a depth imaging sensor is used to capture depth silhouettes. Based on these silhouettes, human skeletons with joint information are produced which are further used for activity recognition and generating their life logs. The life-logging system is divided into two processes. Firstly, the training system includes data collection using a depth camera, feature extraction and training for each activity via Hidden Markov Models. Secondly, after training, the recognition engine starts to recognize the learned activities and produces life logs. The system was evaluated using life logging features against principal component and independent component features and achieved satisfactory recognition rates against the conventional approaches. Experiments conducted on the smart indoor activity datasets and the MSRDailyActivity3D dataset show promising results. The proposed system is directly applicable to any elderly monitoring system, such as monitoring healthcare problems for elderly people, or examining the indoor activities of people at home, office or hospital.

  16. Optimal Design and Real Time Implementation of Autonomous Microgrid Including Active Load

    OpenAIRE

    Mohamed A. Hassan; Muhammed Y. Worku; Mohamed A. Abido

    2018-01-01

    Controller gains and power-sharing parameters are the main parameters affect the dynamic performance of the microgrid. Considering an active load to the autonomous microgrid, the stability problem will be more involved. In this paper, the active load effect on microgrid dynamic stability is explored. An autonomous microgrid including three inverter-based distributed generations (DGs) with an active load is modeled and the associated controllers are designed. Controller gains of the inverters ...

  17. Sensor

    OpenAIRE

    Gleeson, Helen; Dierking, Ingo; Grieve, Bruce; Woodyatt, Christopher; Brimicombe, Paul

    2015-01-01

    An electrical temperature sensor (10) comprises a liquid crystalline material (12). First and second electrically conductive contacts (14), (16), having a spaced relationship there between, contact the liquid crystalline material (12). An electric property measuring device is electrically connected to the first and second contacts (14), (16) and is arranged to measure an electric property of the liquid crystalline material (12). The liquid crystalline material (12) has a transition temperatur...

  18. Precise shape reconstruction by active pattern in total-internal-reflection-based tactile sensor.

    Science.gov (United States)

    Saga, Satoshi; Taira, Ryosuke; Deguchi, Koichiro

    2014-03-01

    We are developing a total-internal-reflection-based tactile sensor in which the shape is reconstructed using an optical reflection. This sensor consists of silicone rubber, an image pattern, and a camera. It reconstructs the shape of the sensor surface from an image of a pattern reflected at the inner sensor surface by total internal reflection. In this study, we propose precise real-time reconstruction by employing an optimization method. Furthermore, we propose to use active patterns. Deformation of the reflection image causes reconstruction errors. By controlling the image pattern, the sensor reconstructs the surface deformation more precisely. We implement the proposed optimization and active-pattern-based reconstruction methods in a reflection-based tactile sensor, and perform reconstruction experiments using the system. A precise deformation experiment confirms the linearity and precision of the reconstruction.

  19. Confronting Passive and Active Sensors with Non-Gaussian Statistics

    Directory of Open Access Journals (Sweden)

    Pablo Rodríguez-Gonzálvez

    2014-07-01

    Full Text Available This paper has two motivations: firstly, to compare the Digital Surface Models (DSM derived by passive (digital camera and by active (terrestrial laser scanner remote sensing systems when applied to specific architectural objects, and secondly, to test how well the Gaussian classic statistics, with its Least Squares principle, adapts to data sets where asymmetrical gross errors may appear and whether this approach should be changed for a non-parametric one. The field of geomatic technology automation is immersed in a high demanding competition in which any innovation by one of the contenders immediately challenges the opponents to propose a better improvement. Nowadays, we seem to be witnessing an improvement of terrestrial photogrammetry and its integration with computer vision to overcome the performance limitations of laser scanning methods. Through this contribution some of the issues of this “technological race” are examined from the point of view of photogrammetry. A new software is introduced and an experimental test is designed, performed and assessed to try to cast some light on this thrilling match. For the case considered in this study, the results show good agreement between both sensors, despite considerable asymmetry. This asymmetry suggests that the standard Normal parameters are not adequate to assess this type of data, especially when accuracy is of importance. In this case, standard deviation fails to provide a good estimation of the results, whereas the results obtained for the Median Absolute Deviation and for the Biweight Midvariance are more appropriate measures.

  20. Application-specific architectures of CMOS monolithic active pixel sensors

    Energy Technology Data Exchange (ETDEWEB)

    Szelezniak, Michal [Institute de Recherches Subatomiques, 23 rue du Loess, Strasbourg 67037 Cedex 02 (France)]. E-mail: michal.szelezniak@ires.in2p3.fr; Besson, Auguste [Institute de Recherches Subatomiques, 23 rue du Loess, Strasbourg 67037 Cedex 02 (France); Claus, Gilles; Colledani, Claude; [Institute de Recherches Subatomiques, 23 rue du Loess, Strasbourg 67037 Cedex 02 (France); Degerli, Yavuz [CEA Saclay, DAPNIA, Gif-sur-Yvette Cedex (France); Deptuch, Grzegorz [Institute de Recherches Subatomiques, 23 rue du Loess, Strasbourg 67037 Cedex 02 (France); Deveaux, Michael [Institute de Recherches Subatomiques, 23 rue du Loess, Strasbourg 67037 Cedex 02 (France); GSI, Planckstrasse 1, Darmstadt 64291 (Germany); Dorokhov, Andrei [Institute de Recherches Subatomiques, 23 rue du Loess, Strasbourg 67037 Cedex 02 (France); Dulinski, Wojciech [Institute de Recherches Subatomiques, 23 rue du Loess, Strasbourg 67037 Cedex 02 (France); Fourches, Nicolas [CEA Saclay, DAPNIA, Gif-sur-Yvette Cedex (France); Goffe, Mathieu [Institute de Recherches Subatomiques, 23 rue du Loess, Strasbourg 67037 Cedex 02 (France); Grandjean, Damien; Guilloux, Fabrice [Institute de Recherches Subatomiques, 23 rue du Loess, Strasbourg 67037 Cedex 02 (France); Heini, Sebastien [Institute de Recherches Subatomiques, 23 rue du Loess, Strasbourg 67037 Cedex 02 (France)]|[GSI, Planckstrasse 1, Darmstadt 64291 (Germany); Himmi, Abdelkader [Institute de Recherches Subatomiques, 23 rue du Loess, Strasbourg 67037 Cedex 02 (France); Hu, Christine [Institute de Recherches Subatomiques, 23 rue du Loess, Strasbourg 67037 Cedex 02 (France); Jaaskelainen, Kimmo; Li, Yan; Lutz, Pierre; Orsini, Fabienne [CEA Saclay, DAPNIA, Gif-sur-Yvette Cedex (France); Pellicioli, Michel; Shabetai, Alexandre; Valin, Isabelle; Winter, Marc [Institute de Recherches Subatomiques, 23 rue du Loess, Strasbourg 67037 Cedex 02 (France)

    2006-11-30

    Several development directions intended to adapt and optimize monolithic active pixel sensors for specific applications are presented in this work. The first example, compatible with the STAR microvertex upgrade, is based on a simple two-transistor pixel circuitry. It is suited for a long integration time, room-temperature operation and minimum power dissipation. In another approach for this application, a specific readout method is proposed, allowing optimization of the integration time independently of the full frame-readout time. The circuit consists of an in-pixel front-end voltage amplifier, with a gain on the order of five, followed by two analog memory cells. The extended version of this scheme, based on the implementation of more memory cells per pixel, is the solution considered for the outer layers of a microvertex detector at the international linear collider. For the two innermost layers, a circuit allowing fast frame scans together with on-line, on-chip data sparsification is proposed. The first results of this prototype demonstrate that the fixed pattern dispersion is reduced below a noise level of 15 e{sup -}, allowing the use of a single comparator or a low-resolution ADC per pixel column. A common element for most of the mentioned readout schemes is a low-noise, low power consumption, layout efficient in-pixel amplifier. A review of possible solutions for this element together with some experimental results is presented.

  1. Submersible microbial fuel cell sensor for monitoring microbial activity and BOD in groundwater: Focusing on impact of anodic biofilm on sensor applicability

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Angelidaki, Irini

    2011-01-01

    was required for application of the sensor for microbial activity measurement, while biofilm‐colonized anode was needed for utilizing the sensor for BOD content measurement. The current density of SUMFC sensor equipped with a biofilm‐colonized anode showed linear relationship with BOD content, to up to 250 mg......A sensor, based on a submersible microbial fuel cell (SUMFC), was developed for in situ monitoring of microbial activity and biochemical oxygen demand (BOD) in groundwater. Presence or absence of a biofilm on the anode was a decisive factor for the applicability of the sensor. Fresh anode...

  2. Structural integrated sensor and actuator systems for active flow control

    Science.gov (United States)

    Behr, Christian; Schwerter, Martin; Leester-Schädel, Monika; Wierach, Peter; Dietzel, Andreas; Sinapius, Michael

    2016-04-01

    An adaptive flow separation control system is designed and implemented as an essential part of a novel high-lift device for future aircraft. The system consists of MEMS pressure sensors to determine the flow conditions and adaptive lips to regulate the mass flow and the velocity of a wall near stream over the internally blown Coanda flap. By the oscillating lip the mass flow in the blowing slot changes dynamically, consequently the momentum exchange of the boundary layer over a high lift flap required mass flow can be reduced. These new compact and highly integrated systems provide a real-time monitoring and manipulation of the flow conditions. In this context the integration of pressure sensors into flow sensing airfoils of composite material is investigated. Mechanical and electrical properties of the integrated sensors are investigated under mechanical loads during tensile tests. The sensors contain a reference pressure chamber isolated to the ambient by a deformable membrane with integrated piezoresistors connected as a Wheatstone bridge, which outputs voltage signals depending on the ambient pressure. The composite material in which the sensors are embedded consists of 22 individual layers of unidirectional glass fiber reinforced plastic (GFRP) prepreg. The results of the experiments are used for adapting the design of the sensors and the layout of the laminate to ensure an optimized flux of force in highly loaded structures primarily for future aeronautical applications. It can be shown that the pressure sensor withstands the embedding process into fiber composites with full functional capability and predictable behavior under stress.

  3. Intelligent error correction method applied on an active pixel sensor based star tracker

    Science.gov (United States)

    Schmidt, Uwe

    2005-10-01

    Star trackers are opto-electronic sensors used on-board of satellites for the autonomous inertial attitude determination. During the last years star trackers became more and more important in the field of the attitude and orbit control system (AOCS) sensors. High performance star trackers are based up today on charge coupled device (CCD) optical camera heads. The active pixel sensor (APS) technology, introduced in the early 90-ties, allows now the beneficial replacement of CCD detectors by APS detectors with respect to performance, reliability, power, mass and cost. The company's heritage in star tracker design started in the early 80-ties with the launch of the worldwide first fully autonomous star tracker system ASTRO1 to the Russian MIR space station. Jena-Optronik recently developed an active pixel sensor based autonomous star tracker "ASTRO APS" as successor of the CCD based star tracker product series ASTRO1, ASTRO5, ASTRO10 and ASTRO15. Key features of the APS detector technology are, a true xy-address random access, the multiple windowing read out and the on-chip signal processing including the analogue to digital conversion. These features can be used for robust star tracking at high slew rates and under worse conditions like stray light and solar flare induced single event upsets. A special algorithm have been developed to manage the typical APS detector error contributors like fixed pattern noise (FPN), dark signal non-uniformity (DSNU) and white spots. The algorithm works fully autonomous and adapts to e.g. increasing DSNU and up-coming white spots automatically without ground maintenance or re-calibration. In contrast to conventional correction methods the described algorithm does not need calibration data memory like full image sized calibration data sets. The application of the presented algorithm managing the typical APS detector error contributors is a key element for the design of star trackers for long term satellite applications like

  4. Virtual sensors for active noise control in acoustic-structural coupled enclosures using structural sensing: robust virtual sensor design.

    Science.gov (United States)

    Halim, Dunant; Cheng, Li; Su, Zhongqing

    2011-03-01

    The work was aimed to develop a robust virtual sensing design methodology for sensing and active control applications of vibro-acoustic systems. The proposed virtual sensor was designed to estimate a broadband acoustic interior sound pressure using structural sensors, with robustness against certain dynamic uncertainties occurring in an acoustic-structural coupled enclosure. A convex combination of Kalman sub-filters was used during the design, accommodating different sets of perturbed dynamic model of the vibro-acoustic enclosure. A minimax optimization problem was set up to determine an optimal convex combination of Kalman sub-filters, ensuring an optimal worst-case virtual sensing performance. The virtual sensing and active noise control performance was numerically investigated on a rectangular panel-cavity system. It was demonstrated that the proposed virtual sensor could accurately estimate the interior sound pressure, particularly the one dominated by cavity-controlled modes, by using a structural sensor. With such a virtual sensing technique, effective active noise control performance was also obtained even for the worst-case dynamics. © 2011 Acoustical Society of America

  5. Evaluation of muscular activity duration in shoulders with rotator cuff tears using inertial sensors and electromyography

    International Nuclear Information System (INIS)

    Duc, Cyntia; Aminian, Kamiar; Pichonnaz, Claude; Farron, Alain; Jolles, Brigitte M; Bassin, Jean-Philippe

    2014-01-01

    Shoulder disorders, including rotator cuff tears, affect the shoulder function and result in adapted muscle activation. Although these adaptations have been studied in controlled conditions, free-living activities have not been investigated. Based on the kinematics measured with inertial sensors and portable electromyography, the objectives of this study were to quantify the duration of the muscular activation in the upper trapezius (UT), medial deltoid (MD) and biceps brachii (BB) during motion and to investigate the effect of rotator cuff tear in laboratory settings and daily conditions. The duration of movements and muscular activations were analysed separately and together using the relative time of activation (T EMG/mov ). Laboratory measurements showed the parameter’s reliability through movement repetitions (ICC > 0.74) and differences in painful shoulders compared with healthy ones (p < 0.05): longer activation for UT; longer activation for MD during abduction and tendency to shorter activation in other movements; shorter activation for BB. In daily conditions, T EMG/mov for UT was longer, whereas it was shorter for MD and BB (p < 0.05). Moreover, significant correlations were observed between these parameters and clinical scores. This study thus provides new insights into the rotator cuff tear effect on duration of muscular activation in daily activity. (paper)

  6. First tests of a novel radiation hard CMOS sensor process for Depleted Monolithic Active Pixel Sensors

    International Nuclear Information System (INIS)

    Pernegger, H.; Hoorne, J.W. van; Kugathasan, T.; Musa, L.; Riedler, P.; Riegel, C.; Schaefer, D.; Schioppa, E.J.; Snoeys, W.; Bates, R.; Buttar, C.; Maneuski, D.; Dalla, M.; Sbarra, C.

    2017-01-01

    The upgrade of the ATLAS [1] tracking detector for the High-Luminosity Large Hadron Collider (LHC) at CERN requires novel radiation hard silicon sensor technologies. Significant effort has been put into the development of monolithic CMOS sensors but it has been a challenge to combine a low capacitance of the sensing node with full depletion of the sensitive layer. Low capacitance brings low analog power. Depletion of the sensitive layer causes the signal charge to be collected by drift sufficiently fast to separate hits from consecutive bunch crossings (25 ns at the LHC) and to avoid losing the charge by trapping. This paper focuses on the characterization of charge collection properties and detection efficiency of prototype sensors originally designed in the framework of the ALICE Inner Tracking System (ITS) upgrade [2]. The prototypes are fabricated both in the standard TowerJazz 180nm CMOS imager process [3] and in an innovative modification of this process developed in collaboration with the foundry, aimed to fully deplete the sensitive epitaxial layer and enhance the tolerance to non-ionizing energy loss. Sensors fabricated in standard and modified process variants were characterized using radioactive sources, focused X-ray beam and test beams before and after irradiation. Contrary to sensors manufactured in the standard process, sensors from the modified process remain fully functional even after a dose of 10"1"5 n _e_q/cm"2, which is the the expected NIEL radiation fluence for the outer pixel layers in the future ATLAS Inner Tracker (ITk) [4].

  7. Compositions of graphene materials with metal nanostructures and microstructures and methods of making and using including pressure sensors

    KAUST Repository

    Chen, Ye; Khashab, Niveen M.; Tao, Jing

    2017-01-01

    Composition comprising at least one graphene material and at least one metal. The metal can be in the form of nanoparticles as well as microflakes, including single crystal microflakes. The metal can be intercalated in the graphene sheets

  8. Active Sensor for Microwave Tissue Imaging with Bias-Switched Arrays.

    Science.gov (United States)

    Foroutan, Farzad; Nikolova, Natalia K

    2018-05-06

    A prototype of a bias-switched active sensor was developed and measured to establish the achievable dynamic range in a new generation of active arrays for microwave tissue imaging. The sensor integrates a printed slot antenna, a low-noise amplifier (LNA) and an active mixer in a single unit, which is sufficiently small to enable inter-sensor separation distance as small as 12 mm. The sensor’s input covers the bandwidth from 3 GHz to 7.5 GHz. Its output intermediate frequency (IF) is 30 MHz. The sensor is controlled by a simple bias-switching circuit, which switches ON and OFF the bias of the LNA and the mixer simultaneously. It was demonstrated experimentally that the dynamic range of the sensor, as determined by its ON and OFF states, is 109 dB and 118 dB at resolution bandwidths of 1 kHz and 100 Hz, respectively.

  9. All-fiber, long-active-length Fabry-Perot strain sensor.

    Science.gov (United States)

    Pevec, Simon; Donlagic, Denis

    2011-08-01

    This paper presents a high-sensitivity, all-silica, all-fiber Fabry-Perot strain-sensor. The proposed sensor provides a long active length, arbitrary length of Fabry-Perot cavity, and low intrinsic temperature sensitivity. The sensor was micro-machined from purposely-developed sensor-forming fiber that is etched and directly spliced to the lead-in fiber. This manufacturing process has good potential for cost-effective, high-volume production. Its measurement range of over 3000 µε, and strain-resolution better than 1 µε were demonstrated by the application of a commercial, multimode fiber-based signal processor.

  10. Metal-Organic Frameworks as Active Materials in Electronic Sensor Devices.

    Science.gov (United States)

    Campbell, Michael G; Dincă, Mircea

    2017-05-12

    In the past decade, advances in electrically conductive metal-organic frameworks (MOFs) and MOF-based electronic devices have created new opportunities for the development of next-generation sensors. Here we review this rapidly-growing field, with a focus on the different types of device configurations that have allowed for the use of MOFs as active components of electronic sensor devices.

  11. Actuator and sensor selection for an active vehicle suspension aimed at robust performance

    NARCIS (Netherlands)

    Wal, van de M.M.J.; Philips, P.P.H.H.; Jager, de A.G.

    1998-01-01

    A recently presented method for actuator and sensor selection for linear control systems is applied and evaluated for an active vehicle suspension control problem. The aim is to eliminate the actuator/sensor combinations for which no controller exists that achieves a specified level of robust

  12. An Active Sensor Algorithm for Corn Nitrogen Recommendations Based on a Chlorophyll Meter Algorithm

    Science.gov (United States)

    In previous work we found active canopy sensor reflectance assessments of corn (Zea mays L.) N status acquired at two growth stages (V11 and V15) have the greatest potential for directing in-season N applications, but emphasized an algorithm was needed to translate sensor readings into appropriate N...

  13. Probing active-edge silicon sensors using a high precision telescope

    NARCIS (Netherlands)

    Akiba, K.; Artuso, M.; van Beveren, V.; van Beuzekom, M.; Boterenbrood, H.; Buytaert, J.; Collins, P.; Dumps, R.; van der Heijden, B.; Hombach, C.; Hynds, D.; Hsu, D.; John, M.; Koffeman, E.; Leflat, A.; Li, Y.; Longstaff, I.; Morton, A.; PérezTrigo, E.; Plackett, R.; Reid, M.M.; Rodríguez Perez, P.; Schindler, H.; Tsopelas, P.; Vázquez Sierra, C.; Wysokiński, M.

    2015-01-01

    The performance of prototype active-edge VTT sensors bump-bonded to the Timepix ASIC is presented. Non-irradiated sensors of thicknesses 100-200 μm and pixel-to-edge distances of 50 μm and 100 μm were probed with a beam of charged hadrons with sub-pixel precision using the Timepix telescope

  14. Active damage localization for plate-like structures using wireless sensors and a distributed algorithm

    International Nuclear Information System (INIS)

    Liu, L; Yuan, F G

    2008-01-01

    Wireless structural health monitoring (SHM) systems have emerged as a promising technology for robust and cost-effective structural monitoring. However, the applications of wireless sensors on active diagnosis for structural health monitoring (SHM) have not been extensively investigated. Due to limited energy sources, battery-powered wireless sensors can only perform limited functions and are expected to operate at a low duty cycle. Conventional designs are not suitable for sensing high frequency signals, e.g. in the ultrasonic frequency range. More importantly, algorithms to detect structural damage with a vast amount of data usually require considerable processing and communication time and result in unaffordable power consumption for wireless sensors. In this study, an energy-efficient wireless sensor for supporting high frequency signals and a distributed damage localization algorithm for plate-like structures are proposed, discussed and validated to supplement recent advances made for active sensing-based SHM. First, the power consumption of a wireless sensor is discussed and identified. Then the design of a wireless sensor for active diagnosis using piezoelectric sensors is introduced. The newly developed wireless sensor utilizes an optimized combination of field programmable gate array (FPGA) and conventional microcontroller to address the tradeoff between power consumption and speed requirement. The proposed damage localization algorithm, based on an energy decay model, enables wireless sensors to be practically used in active diagnosis. The power consumption for data communication can be minimized while the power budget for data processing can still be affordable for a battery-powered wireless sensor. The Levenberg–Marquardt method is employed in a mains-powered sensor node or PC to locate damage. Experimental results and discussion on the improvement of power efficiency are given

  15. Unified theory of dislocation motion including thermal activation and inertial effects

    International Nuclear Information System (INIS)

    Isaac, R.D.; Granato, A.V.

    1979-01-01

    Transition-state rate theory has generally been used to explain the temperature dependence of the flow stress of a crystal. However, the existence of a change in the flow stress during the superconducting transition indicates the presence of inertial effects in which dislocations overcome obstacles mechanically rather than thermally. It is shown here that the thermally activated and the inertial overcoming of obstacles are not unrelated but can both be derived from principles of stochastic motion. This leads to a theory of dislocation motion that includes both thermal activation and inertial effects. It is also shown that a distribution of activation energies must be considered to account for the experimental data

  16. A Novel Wearable Sensor-Based Human Activity Recognition Approach Using Artificial Hydrocarbon Networks.

    Science.gov (United States)

    Ponce, Hiram; Martínez-Villaseñor, María de Lourdes; Miralles-Pechuán, Luis

    2016-07-05

    Human activity recognition has gained more interest in several research communities given that understanding user activities and behavior helps to deliver proactive and personalized services. There are many examples of health systems improved by human activity recognition. Nevertheless, the human activity recognition classification process is not an easy task. Different types of noise in wearable sensors data frequently hamper the human activity recognition classification process. In order to develop a successful activity recognition system, it is necessary to use stable and robust machine learning techniques capable of dealing with noisy data. In this paper, we presented the artificial hydrocarbon networks (AHN) technique to the human activity recognition community. Our artificial hydrocarbon networks novel approach is suitable for physical activity recognition, noise tolerance of corrupted data sensors and robust in terms of different issues on data sensors. We proved that the AHN classifier is very competitive for physical activity recognition and is very robust in comparison with other well-known machine learning methods.

  17. Inductive Displacement Sensors with a Notch Filter for an Active Magnetic Bearing System

    Directory of Open Access Journals (Sweden)

    Seng-Chi Chen

    2014-07-01

    Full Text Available Active magnetic bearing (AMB systems support rotating shafts without any physical contact, using electromagnetic forces. Each radial AMB uses two pairs of electromagnets at opposite sides of the rotor. This allows the rotor to float in the air gap, and the machine to operate without frictional losses. In active magnetic suspension, displacement sensors are necessary to detect the radial and axial movement of the suspended object. In a high-speed rotating machine equipped with an AMB, the rotor bending modes may be limited to the operating range. The natural frequencies of the rotor can cause instability. Thus, notch filters are a useful circuit for stabilizing the system. In addition, commercial displacement sensors are sometimes not suitable for AMB design, and cannot filter the noise caused by the natural frequencies of rotor. Hence, implementing displacement sensors based on the AMB structure is necessary to eliminate noises caused by natural frequency disturbances. The displacement sensor must be highly sensitive in the desired working range, and also exhibit a low interference noise, high stability, and low cost. In this study, we used the differential inductive sensor head and lock-in amplifier for synchronous demodulation. In addition, an active low-pass filter and a notch filter were used to eliminate disturbances, which caused by natural frequencies. As a consequence, the inductive displacement sensor achieved satisfactory linearity, high sensitivity, and disturbance elimination. This sensor can be easily produced for AMB applications. A prototype of these displacement sensors was built and tested.

  18. Inductive displacement sensors with a notch filter for an active magnetic bearing system.

    Science.gov (United States)

    Chen, Seng-Chi; Le, Dinh-Kha; Nguyen, Van-Sum

    2014-07-15

    Active magnetic bearing (AMB) systems support rotating shafts without any physical contact, using electromagnetic forces. Each radial AMB uses two pairs of electromagnets at opposite sides of the rotor. This allows the rotor to float in the air gap, and the machine to operate without frictional losses. In active magnetic suspension, displacement sensors are necessary to detect the radial and axial movement of the suspended object. In a high-speed rotating machine equipped with an AMB, the rotor bending modes may be limited to the operating range. The natural frequencies of the rotor can cause instability. Thus, notch filters are a useful circuit for stabilizing the system. In addition, commercial displacement sensors are sometimes not suitable for AMB design, and cannot filter the noise caused by the natural frequencies of rotor. Hence, implementing displacement sensors based on the AMB structure is necessary to eliminate noises caused by natural frequency disturbances. The displacement sensor must be highly sensitive in the desired working range, and also exhibit a low interference noise, high stability, and low cost. In this study, we used the differential inductive sensor head and lock-in amplifier for synchronous demodulation. In addition, an active low-pass filter and a notch filter were used to eliminate disturbances, which caused by natural frequencies. As a consequence, the inductive displacement sensor achieved satisfactory linearity, high sensitivity, and disturbance elimination. This sensor can be easily produced for AMB applications. A prototype of these displacement sensors was built and tested.

  19. ESAM: Endocrine inspired Sensor Activation Mechanism for multi-target tracking in WSNs

    Science.gov (United States)

    Adil Mahdi, Omar; Wahab, Ainuddin Wahid Abdul; Idris, Mohd Yamani Idna; Znaid, Ammar Abu; Khan, Suleman; Al-Mayouf, Yusor Rafid Bahar

    2016-10-01

    Target tracking is a significant application of wireless sensor networks (WSNs) in which deployment of self-organizing and energy efficient algorithms is required. The tracking accuracy increases as more sensor nodes are activated around the target but more energy is consumed. Thus, in this study, we focus on limiting the number of sensors by forming an ad-hoc network that operates autonomously. This will reduce the energy consumption and prolong the sensor network lifetime. In this paper, we propose a fully distributed algorithm, an Endocrine inspired Sensor Activation Mechanism for multi target-tracking (ESAM) which reflecting the properties of real life sensor activation system based on the information circulating principle in the endocrine system of the human body. Sensor nodes in our network are secreting different hormones according to certain rules. The hormone level enables the nodes to regulate an efficient sleep and wake up cycle of nodes to reduce the energy consumption. It is evident from the simulation results that the proposed ESAM in autonomous sensor network exhibits a stable performance without the need of commands from a central controller. Moreover, the proposed ESAM generates more efficient and persistent results as compared to other algorithms for tracking an invading object.

  20. Increasing the Lifetime of Mobile WSNs via Dynamic Optimization of Sensor Node Communication Activity.

    Science.gov (United States)

    Guimarães, Dayan Adionel; Sakai, Lucas Jun; Alberti, Antonio Marcos; de Souza, Rausley Adriano Amaral

    2016-09-20

    In this paper, a simple and flexible method for increasing the lifetime of fixed or mobile wireless sensor networks is proposed. Based on past residual energy information reported by the sensor nodes, the sink node or another central node dynamically optimizes the communication activity levels of the sensor nodes to save energy without sacrificing the data throughput. The activity levels are defined to represent portions of time or time-frequency slots in a frame, during which the sensor nodes are scheduled to communicate with the sink node to report sensory measurements. Besides node mobility, it is considered that sensors' batteries may be recharged via a wireless power transmission or equivalent energy harvesting scheme, bringing to the optimization problem an even more dynamic character. We report large increased lifetimes over the non-optimized network and comparable or even larger lifetime improvements with respect to an idealized greedy algorithm that uses both the real-time channel state and the residual energy information.

  1. Triple Active Antiretroviral Regimen Including Enfuvirtide Via the Biojector is Effective and Safe

    Directory of Open Access Journals (Sweden)

    Mona Loutfy

    2007-01-01

    Full Text Available For full HIV virological suppression, three fully active antiretroviral agents are required. New drug classes should be included to ensure that agents are fully active. The addition of enfuvirtide and efavirenz to the present patient’s new antiretroviral regimen ensured that two fully active agents were in use in the setting of a moderate degree of nucleoside resistance and a high level of protease resistance, and where non-nucleoside reverse transcriptase inhibitors were still fully active. Both viral load and CD4 count responded favourably to this regimen. The patient received support from physicians and clinic staff in the introduction and use of enfuvirtide. To reduce injection site reactions, a needle-free injection system (Biojector proved effective.

  2. Radarometer Sensor - Simultaneous Active and Passive Imaging Usin a Common Antenna

    National Research Council Canada - National Science Library

    Huddleston, Darryl

    1999-01-01

    ... ̂ frequency band at a nominal pixel scanning rate of 1,000 per second. The radarometer sensor is capable of operating in both the passive and active modes either individually, in time sequence, or simultaneously...

  3. Sensor-based Human Activity Recognition in a Multi-user Scenario

    DEFF Research Database (Denmark)

    Wang, Liang; Gu, Tao; Tao, Xianping

    2009-01-01

    Existing work on sensor-based activity recognition focuses mainly on single-user activities. However, in real life, activities are often performed by multiple users involving interactions between them. In this paper, we propose Coupled Hidden Markov Models (CHMMs) to recognize multi-user activiti...

  4. Peptidase inhibitors reduce opiate narcotic withdrawal signs, including seizure activity, in the rat.

    Science.gov (United States)

    Pinsky, C; Dua, A K; LaBella, F S

    1982-07-15

    Narcotic withdrawal was precipitated by administration of naloxone in a low dose at 2 h after the final dose of morphine in a 9-day dependency-inducing schedule. Withdrawal was characterized by leaps, increased nocifensor activity and by cerebral cortical epileptiform activity, the latter not generally reported to be prominent in narcotic withdrawal. Single large doses of morphine did not provoke epileptiform activity at 2 h postinjection but did induce an acute opioid dependency wherein a moderately high dose of naloxone, ineffective in non-dependent rats, provoked upward leaping and electrocortical epileptiform activity. Pretreatment of the 9-day dependent rats with peptidase inhibitors, administered intracerebroventricularly, significantly reduced withdrawal severity including the epileptiform activity. We propose that peptidase inhibitors protect certain species of endogenous opioids and/or other neuropeptides that tend to suppress expression of the narcotic withdrawal syndrome. Furthermore, our findings suggest that epileptiform activity is a nascent form of cerebral activity hitherto largely unnoticed in narcotic withdrawal and that neuropeptides may be involved in certain epileptic states.

  5. Novel bacterial gas sensor proteins with transition metal-containing prosthetic groups as active sites.

    Science.gov (United States)

    Aono, Shigetoshi

    2012-04-01

    Gas molecules function as signaling molecules in many biological regulatory systems responsible for transcription, chemotaxis, and other complex physiological processes. Gas sensor proteins play a crucial role in regulating such biological systems in response to gas molecules. New sensor proteins that sense oxygen or nitric oxide have recently been found, and they have been characterized by X-ray crystallographic and/or spectroscopic analysis. It has become clear that the interaction between a prosthetic group and gas molecules triggers dynamic structural changes in the protein backbone when a gas sensor protein senses gas molecules. Gas sensor proteins employ novel mechanisms to trigger conformational changes in the presence of a gas. In gas sensor proteins that have iron-sulfur clusters as active sites, the iron-sulfur clusters undergo structural changes, which trigger a conformational change. Heme-based gas sensor proteins reconstruct hydrogen-bonding networks around the heme and heme-bound ligand. Gas sensor proteins have two functional states, on and off, which are active and inactive, respectively, for subsequent signal transduction in response to their physiological effector molecules. To fully understand the structure-function relationships of gas sensor proteins, it is vital to perform X-ray crystal structure analyses of full-length proteins in both the on and off states.

  6. Characterization and re-activation of oxygen sensors for use in liquid lead-bismuth

    International Nuclear Information System (INIS)

    Kurata, Yuji; Abe, Yuji; Futakawa, Masatoshi; Oigawa, Hiroyuki

    2010-01-01

    Control of oxygen concentration in liquid lead-bismuth is one of the most important tasks to develop accelerator driven systems. In order to improve the reliability of oxygen sensors, re-activation treatments were investigated as well as characterization of oxygen sensors for use in liquid lead-bismuth. The oxygen sensor with a solid electrolyte of yttria-stabilized zirconia and a Pt/gas reference electrode showed almost the same electromotive force values in gas and liquid lead-bismuth, respectively, as the theoretical ones at temperatures above 400 deg. C or 450 deg. C. After long-term use of 6500 h, the outputs of the sensor became incorrect in liquid lead-bismuth. The state of the sensor that indicated incorrect outputs could not be recovered by cleaning with a nitric acid. However, it was found that the oxygen sensor became a correct sensor indicating theoretical values in liquid lead-bismuth after re-activation by the Pt-treatment of the outer surface of the sensor.

  7. EPA activities related to emerging air sensor technology

    Science.gov (United States)

    This slide set was developed through contributions of NERL and NRMRL research groups and organized to explain the diversity of ongoing research related to emerging air sensor technology for an international audience. Gayle will be walking OAQPS through the slide set in advance o...

  8. Activity recognition based on inertial sensors for ambient assisted living

    NARCIS (Netherlands)

    Davis, K.; Owusu, E.; Bastani, V.; Marcenaro, L.; Hu, J.; Regazzoni, C.; Feijs, L.M.G.

    2016-01-01

    Ambient Assisted Living (AAL) aims to create innovative technical solutions and services to support independent living among older adults, improve their quality of life and reduce the costs associated with health and social care. AAL systems provide health monitoring through sensor based

  9. A Secure Behavior Modification Sensor System for Physical Activity Improvement

    Science.gov (United States)

    Price, Alan

    2011-01-01

    Today, advances in wireless sensor networks are making it possible to capture large amounts of information about a person and their interaction within their home environment. However, what is missing is how to ensure the security of the collected data and its use to alter human behavior for positive benefit. In this research, exploration was…

  10. Heat-activated Plasmonic Chemical Sensors for Harsh Environments

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, Michael [SUNY Polytechnic Inst., Albany, NY (United States); Oh, Sang-Hyun [Univ. of Minnesota, Minneapolis, MN (United States)

    2015-12-01

    A passive plasmonics based chemical sensing system to be used in harsh operating environments was investigated and developed within this program. The initial proposed technology was based on combining technologies developed at the SUNY Polytechnic Institute Colleges of Nanoscale Science and Engineering (CNSE) and at the University of Minnesota (UM). Specifically, a passive wireless technique developed at UM was to utilize a heat-activated plasmonic design to passively harvest the thermal energy from within a combustion emission stream and convert this into a narrowly focused light source. This plasmonic device was based on a bullseye design patterned into a gold film using focused ion beam methods (FIB). Critical to the design was the use of thermal stabilizing under and overlayers surrounding the gold film. These stabilizing layers were based on both atomic layer deposited films as well as metal laminate layers developed by United Technologies Aerospace Systems (UTAS). While the bullseye design was never able to be thermally stabilized for operating temperatures of 500oC or higher, an alternative energy harvesting design was developed by CNSE within this program. With this new development, plasmonic sensing results are presented where thermal energy is harvested using lithographically patterned Au nanorods, replacing the need for an external incident light source. Gas sensing results using the harvested thermal energy are in good agreement with sensing experiments, which used an external incident light source. Principal Component Analysis (PCA) was used to reduce the wavelength parameter space from 665 variables down to 4 variables with similar levels of demonstrated selectivity. The method was further improved by patterning rods which harvested energy in the near infrared, which led to a factor of 10 decrease in data acquisition times as well as demonstrated selectivity with a reduced wavelength data set. The combination of a plasmonic-based energy harvesting

  11. Organic magnetic field sensor

    Energy Technology Data Exchange (ETDEWEB)

    McCamey, Dane; Boehme, Christoph

    2017-01-24

    An organic, spin-dependent magnetic field sensor (10) includes an active stack (12) having an organic material with a spin-dependence. The sensor (10) also includes a back electrical contact (14) electrically coupled to a back of the active stack (12) and a front electrical contact (16) electrically coupled to a front of the active stack (12). A magnetic field generator (18) is oriented so as to provide an oscillating magnetic field which penetrates the active stack (12).

  12. Passive sensor technology interface to assess elder activity in independent living.

    Science.gov (United States)

    Alexander, Gregory L; Wakefield, Bonnie J; Rantz, Marilyn; Skubic, Marjorie; Aud, Myra A; Erdelez, Sanda; Ghenaimi, Said Al

    2011-01-01

    The effectiveness of clinical information systems to improve nursing and patient outcomes depends on human factors, including system usability, organizational workflow, and user satisfaction. The aim of this study was to examine to what extent residents, family members, and clinicians find a sensor data interface used to monitor elder activity levels usable and useful in an independent living setting. Three independent expert reviewers conducted an initial heuristic evaluation. Subsequently, 20 end users (5 residents, 5 family members, 5 registered nurses, and 5 physicians) participated in the evaluation. During the evaluation, each participant was asked to complete three scenarios taken from three residents. Morae recorder software was used to capture data during the user interactions. The heuristic evaluation resulted in 26 recommendations for interface improvement; these were classified under the headings content, aesthetic appeal, navigation, and architecture, which were derived from heuristic results. Total time for elderly residents to complete scenarios was much greater than for other users. Family members spent more time than clinicians but less time than residents did to complete scenarios. Elder residents and family members had difficulty interpreting clinical data and graphs, experienced information overload, and did not understand terminology. All users found the sensor data interface useful for identifying changing resident activities. Older adult users have special needs that should be addressed when designing clinical interfaces for them, especially information as important as health information. Evaluating human factors during user interactions with clinical information systems should be a requirement before implementation.

  13. Sensor-Based Human Activity Recognition in a Multi-user Scenario

    Science.gov (United States)

    Wang, Liang; Gu, Tao; Tao, Xianping; Lu, Jian

    Existing work on sensor-based activity recognition focuses mainly on single-user activities. However, in real life, activities are often performed by multiple users involving interactions between them. In this paper, we propose Coupled Hidden Markov Models (CHMMs) to recognize multi-user activities from sensor readings in a smart home environment. We develop a multimodal sensing platform and present a theoretical framework to recognize both single-user and multi-user activities. We conduct our trace collection done in a smart home, and evaluate our framework through experimental studies. Our experimental result shows that we achieve an average accuracy of 85.46% with CHMMs.

  14. Interference Mitigation Technique Using Active Spaceborne Sensor Antenna in EESS (Active) and Space Research Service (Active) for Use in 500 MHz Bandwidth Near 9.6 GHz

    Science.gov (United States)

    Huneycutt, Bryan L.

    2005-01-01

    This document presents an interference mitigation technique using the active spaceborne sensor SAR3 antenna in the Earth Exploration-Satellite Service (active) and Space Research Service (active) for use in a 500 MHz bandwidth near 9.6 GHz. The purpose of the document is present antenna designs which offer lower sidelobes and faster rolloff in the sidelobes which in turn mitigates the interference to other services from the EESS (active) and SRS (active) sensors.

  15. X-ray imaging characterization of active edge silicon pixel sensors

    International Nuclear Information System (INIS)

    Ponchut, C; Ruat, M; Kalliopuska, J

    2014-01-01

    The aim of this work was the experimental characterization of edge effects in active-edge silicon pixel sensors, in the frame of X-ray pixel detectors developments for synchrotron experiments. We produced a set of active edge pixel sensors with 300 to 500 μm thickness, edge widths ranging from 100 μm to 150 μm, and n or p pixel contact types. The sensors with 256 × 256 pixels and 55 × 55 μm 2 pixel pitch were then bump-bonded to Timepix readout chips for X-ray imaging measurements. The reduced edge widths makes the edge pixels more sensitive to the electrical field distribution at the sensor boundaries. We characterized this effect by mapping the spatial response of the sensor edges with a finely focused X-ray synchrotron beam. One of the samples showed a distortion-free response on all four edges, whereas others showed variable degrees of distortions extending at maximum to 300 micron from the sensor edge. An application of active edge pixel sensors to coherent diffraction imaging with synchrotron beams is described

  16. Development of isoform-specific sensors of polypeptide GalNAc-transferase activity

    DEFF Research Database (Denmark)

    Song, Lina; Bachert, Collin; Schjoldager, Katrine T

    2014-01-01

    sequence influenced their activity and required modification, which we carried out based on previous in vitro work. Significantly, the modified T2 and T3 sensors were activated only in cells lacking their corresponding isozymes. Thus, we have developed T2- and T3-specific sensors that will be valuable......Humans express up to 20 isoforms of GalNAc-transferase (herein T1-T20) that localize to the Golgi apparatus and initiate O-glycosylation. Regulation of this enzyme family affects a vast array of proteins transiting the secretory pathway and diseases arise upon misregulation of specific isoforms....... Surprisingly, molecular probes to monitor GalNAc-transferase activity are lacking and there exist no effective global or isoform-specific inhibitors. Here we describe the development of T2- and T3-isoform specific fluorescence sensors that traffic in the secretory pathway. Each sensor yielded little signal...

  17. Probing active-edge silicon sensors using a high precision telescope

    Energy Technology Data Exchange (ETDEWEB)

    Akiba, K. [Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); Artuso, M. [Syracuse University, Syracuse, NY (United States); Beveren, V. van; Beuzekom, M. van; Boterenbrood, H. [Nikhef, Amsterdam (Netherlands); Buytaert, J.; Collins, P.; Dumps, R. [CERN, the European Organisation for Nuclear Research, Geneva (Switzerland); Heijden, B. van der [Nikhef, Amsterdam (Netherlands); Hombach, C. [University of Manchester, Manchester, Lancashire (United Kingdom); Hynds, D. [Glasgow University, Glasgow, Lanarkshire (United Kingdom); Hsu, D. [Syracuse University, Syracuse, NY (United States); John, M. [University of Oxford, Oxfordshire (United Kingdom); Koffeman, E. [Nikhef, Amsterdam (Netherlands); Leflat, A. [Lomonosov Moscow State University, Moscow (Russian Federation); Li, Y. [Tsinghua University, Beijing (China); Longstaff, I.; Morton, A. [Glasgow University, Glasgow, Lanarkshire (United Kingdom); Pérez Trigo, E. [Universidade de Santiago de Compostela, Santiago de Compostela (Spain); Plackett, R. [Diamond Light Source Ltd., Didcot, Oxfordshire (United Kingdom); and others

    2015-03-21

    The performance of prototype active-edge VTT sensors bump-bonded to the Timepix ASIC is presented. Non-irradiated sensors of thicknesses 100–200 μm and pixel-to-edge distances of 50 μm and 100 μm were probed with a beam of charged hadrons with sub-pixel precision using the Timepix telescope assembled at the SPS at CERN. The sensors are shown to be highly efficient up to a few micrometers from the physical edge of the sensor. The distortion of the electric field lines at the edge of the sensors is studied by reconstructing the streamlines of the electric field using two-pixel clusters. These results are supported by TCAD simulations. The reconstructed streamlines are used to study the field distortion as a function of the bias voltage and to apply corrections to the cluster positions at the edge.

  18. Geant4-based simulations of charge collection in CMOS Active Pixel Sensors

    International Nuclear Information System (INIS)

    Esposito, M.; Allinson, N.M.; Price, T.; Anaxagoras, T.

    2017-01-01

    Geant4 is an object-oriented toolkit for the simulation of the interaction of particles and radiation with matter. It provides a snapshot of the state of a simulated particle in time, as it travels through a specified geometry. One important area of application is the modelling of radiation detector systems. Here, we extend the abilities of such modelling to include charge transport and sharing in pixelated CMOS Active Pixel Sensors (APSs); though similar effects occur in other pixel detectors. The CMOS APSs discussed were developed in the framework of the PRaVDA consortium to assist the design of custom sensors to be used in an energy-range detector for proton Computed Tomography (pCT). The development of ad-hoc classes, providing a charge transport model for a CMOS APS and its integration into the standard Geant4 toolkit, is described. The proposed charge transport model includes, charge generation, diffusion, collection, and sharing across adjacent pixels, as well as the full electronic chain for a CMOS APS. The proposed model is validated against experimental data acquired with protons in an energy range relevant for pCT.

  19. Active photonic sensor communication cable for field application of optical data and power transmission

    Science.gov (United States)

    Suthau, Eike; Rieske, Ralf; Zerna, Thomas

    2014-10-01

    Omitting electrically conducting wires for sensor communication and power supply promises protection for sensor systems and monitored structures against lightning or high voltages, prevention of explosion hazards, and reduction of susceptibility to tampering. The ability to photonically power remote systems opens up the full range of electrical sensors. Power-over-fiber is an attractive option in electromagnetically sensitive environments, particularly for longterm, maintenance-free applications. It can deliver uninterrupted power sufficient for elaborate sensors, data processing or even actuators alongside continuous high speed data communication for remote sensor application. This paper proposes an active photonic sensor communication system, which combines the advantages of optical data links in terms of immunity to electromagnetic interference (EMI), high bandwidth, hardiness against tampering or eavesdropping, and low cable weight with the robustness one has come to expect from industrial or military electrical connectors. An application specific integrated circuit (ASIC) is presented that implements a closed-loop regulation of the sensor power supply to guarantee continuous, reliable data communications while maintaining a highly efficient, adaptive sensor supply scheme. It is demonstrated that the resulting novel photonic sensor communication cable can handle sensors and actuators differing orders of magnitude with respect to power consumption. The miniaturization of the electro-optical converters and driving electronics is as important to the presented development as the energy efficiency of the detached, optically powered sensor node. For this reason, a novel photonic packaging technology based on wafer-level assembly of the laser power converters by means of passive alignment will be disclosed in this paper.

  20. Microfluidic electrochemical sensor for on-line monitoring of aerosol oxidative activity.

    Science.gov (United States)

    Sameenoi, Yupaporn; Koehler, Kirsten; Shapiro, Jeff; Boonsong, Kanokporn; Sun, Yele; Collett, Jeffrey; Volckens, John; Henry, Charles S

    2012-06-27

    Particulate matter (PM) air pollution has a significant impact on human morbidity and mortality; however, the mechanisms of PM-induced toxicity are poorly defined. A leading hypothesis states that airborne PM induces harm by generating reactive oxygen species in and around human tissues, leading to oxidative stress. We report here a system employing a microfluidic electrochemical sensor coupled directly to a particle-into-liquid sampler (PILS) system to measure aerosol oxidative activity in an on-line format. The oxidative activity measurement is based on the dithiothreitol (DTT) assay, where, after being oxidized by PM, the remaining reduced DTT is analyzed by the microfluidic sensor. The sensor consists of an array of working, reference, and auxiliary electrodes fabricated in a poly(dimethylsiloxane)-based microfluidic device. Cobalt(II) phthalocyanine-modified carbon paste was used as the working electrode material, allowing selective detection of reduced DTT. The electrochemical sensor was validated off-line against the traditional DTT assay using filter samples taken from urban environments and biomass burning events. After off-line characterization, the sensor was coupled to a PILS to enable on-line sampling/analysis of aerosol oxidative activity. Urban dust and industrial incinerator ash samples were aerosolized in an aerosol chamber and analyzed for their oxidative activity. The on-line sensor reported DTT consumption rates (oxidative activity) in good correlation with aerosol concentration (R(2) from 0.86 to 0.97) with a time resolution of approximately 3 min.

  1. Optimal Design and Real Time Implementation of Autonomous Microgrid Including Active Load

    Directory of Open Access Journals (Sweden)

    Mohamed A. Hassan

    2018-05-01

    Full Text Available Controller gains and power-sharing parameters are the main parameters affect the dynamic performance of the microgrid. Considering an active load to the autonomous microgrid, the stability problem will be more involved. In this paper, the active load effect on microgrid dynamic stability is explored. An autonomous microgrid including three inverter-based distributed generations (DGs with an active load is modeled and the associated controllers are designed. Controller gains of the inverters and active load as well as Phase Locked Loop (PLL parameters are optimally tuned to guarantee overall system stability. A weighted objective function is proposed to minimize the error in both measured active power and DC voltage based on time-domain simulations. Different AC and DC disturbances are applied to verify and assess the effectiveness of the proposed control strategy. The results demonstrate the potential of the proposed controller to enhance the microgrid stability and to provide efficient damping characteristics. Additionally, the proposed controller is compared with the literature to demonstrate its superiority. Finally, the microgrid considered has been established and implemented on real time digital simulator (RTDS. The experimental results validate the simulation results and approve the effectiveness of the proposed controllers to enrich the stability of the considered microgrid.

  2. Toward transparent and self-activated graphene harmonic transponder sensors

    Science.gov (United States)

    Huang, Haiyu Harry; Sakhdari, Maryam; Hajizadegan, Mehdi; Shahini, Ali; Akinwande, Deji; Chen, Pai-Yen

    2016-04-01

    We propose the concept and design of a transparent, flexible, and self-powered wireless sensor comprising a graphene-based sensor/frequency-modulator circuitry and a graphene antenna. In this all-graphene device, the multilayered-graphene antenna receives the fundamental tone at C band and retransmits the frequency-modulated sensed signal (harmonic tone) at X band. The frequency orthogonality between the received/re-transmitted signals may enable high-performance sensing in severe interference/clutter background. Here, a fully passive, quad-ring frequency multiplier is proposed using graphene field-effect transistors, of which the unique ambipolar charge transports render a frequency doubling effect with conversion gain being chemically sensitive to exposed gas/molecular/chemical/infectious agents. This transparent, light-weight, and self-powered system may potentially benefit a number of wireless sensing and diagnosis applications, particularly for smart contact lenses/glasses and microscope slides that require high optical transparency.

  3. Complex Human Activity Recognition Using Smartphone and Wrist-Worn Motion Sensors.

    Science.gov (United States)

    Shoaib, Muhammad; Bosch, Stephan; Incel, Ozlem Durmaz; Scholten, Hans; Havinga, Paul J M

    2016-03-24

    The position of on-body motion sensors plays an important role in human activity recognition. Most often, mobile phone sensors at the trouser pocket or an equivalent position are used for this purpose. However, this position is not suitable for recognizing activities that involve hand gestures, such as smoking, eating, drinking coffee and giving a talk. To recognize such activities, wrist-worn motion sensors are used. However, these two positions are mainly used in isolation. To use richer context information, we evaluate three motion sensors (accelerometer, gyroscope and linear acceleration sensor) at both wrist and pocket positions. Using three classifiers, we show that the combination of these two positions outperforms the wrist position alone, mainly at smaller segmentation windows. Another problem is that less-repetitive activities, such as smoking, eating, giving a talk and drinking coffee, cannot be recognized easily at smaller segmentation windows unlike repetitive activities, like walking, jogging and biking. For this purpose, we evaluate the effect of seven window sizes (2-30 s) on thirteen activities and show how increasing window size affects these various activities in different ways. We also propose various optimizations to further improve the recognition of these activities. For reproducibility, we make our dataset publicly available.

  4. Two-sensor control in active vibration isolation using hard mounts

    NARCIS (Netherlands)

    Beijen, M.A.; Tjepkema, D.; van Dijk, J.

    To isolate precision machines from floor vibrations, active vibration isolators are often applied. In this paper, a two-sensor control strategy, based on acceleration feedback and force feedback, is proposed for an active vibration isolator using a single-axis active hard mount. The hard mount

  5. Two-sensor control in active vibration isolation using hard mounts

    NARCIS (Netherlands)

    Beijen, M.A.; Tjepkema, D.; van Dijk, Johannes

    2014-01-01

    To isolate precision machines from floor vibrations, active vibration isolators are often applied. In this paper, a two-sensor control strategy, based on acceleration feedback and force feedback, is proposed for an active vibration isolator using a single-axis active hard mount. The hard mount

  6. Managing nuclear knowledge: IAEA activities and international coordination. Including resource material full text CD-ROM

    International Nuclear Information System (INIS)

    2005-06-01

    The present CD-ROM summarizes some activities carried out by the Departments of Nuclear Energy and Nuclear Safety and Security in the area of nuclear knowledge management in the period 2003-2005. It comprises, as open resource, most of the relevant documents in full text, including policy level documents, reports, presentation material by Member States and meeting summaries. The collection starts with a reprint of the report to the IAEA General Conference 2004 on Nuclear Knowledge [GOV/2004/56-GC(48)/12] summarizing the developments in nuclear knowledge management since the 47th session of the General Conference in 2003 and covers Managing Nuclear Knowledge including safety issues and Information and Strengthening Education and Training for Capacity Building. It contains an excerpt on Nuclear Knowledge from the General Conference Resolution [GC(48)/RES/13] on Strengthening the Agency's Activities Related to Nuclear Science, Technology and Applications. On the CD-ROM itself, all documents can easily be accessed by clicking on their titles on the subject pages (also printed at the end of this Working Material). Part 1 of the CD-ROM covers the activities in the period 2003-2005 and part 2 presents a resource material full text CD-ROM on Managing Nuclear Knowledge issued in October 2003

  7. SVM-based multimodal classification of activities of daily living in Health Smart Homes: sensors, algorithms, and first experimental results.

    Science.gov (United States)

    Fleury, Anthony; Vacher, Michel; Noury, Norbert

    2010-03-01

    By 2050, about one third of the French population will be over 65. Our laboratory's current research focuses on the monitoring of elderly people at home, to detect a loss of autonomy as early as possible. Our aim is to quantify criteria such as the international activities of daily living (ADL) or the French Autonomie Gerontologie Groupes Iso-Ressources (AGGIR) scales, by automatically classifying the different ADL performed by the subject during the day. A Health Smart Home is used for this. Our Health Smart Home includes, in a real flat, infrared presence sensors (location), door contacts (to control the use of some facilities), temperature and hygrometry sensor in the bathroom, and microphones (sound classification and speech recognition). A wearable kinematic sensor also informs postural transitions (using pattern recognition) and walk periods (frequency analysis). This data collected from the various sensors are then used to classify each temporal frame into one of the ADL that was previously acquired (seven activities: hygiene, toilet use, eating, resting, sleeping, communication, and dressing/undressing). This is done using support vector machines. We performed a 1-h experimentation with 13 young and healthy subjects to determine the models of the different activities, and then we tested the classification algorithm (cross validation) with real data.

  8. Enzymatically active 2',5'-oligoadenylate synthetases are widely distributed among Metazoa, including protostome lineage.

    Science.gov (United States)

    Päri, Mailis; Kuusksalu, Anne; Lopp, Annika; Kjaer, Karina Hansen; Justesen, Just; Kelve, Merike

    2014-02-01

    2',5'-Oligoadenylate synthetases (OASs) belong to the nucleotidyl transferase family together with poly(A) polymerases, CCA-adding enzymes and the recently discovered cyclic-GMP-AMP synthase (cGAS). Mammalian OASs have been thoroughly characterized as components of the interferon-induced antiviral system. The OAS activity and the respective genes were also discovered in marine sponges where the interferon system is absent. In this study the recombinant OASs from several multicellular animals and their closest unicellular relative, a choanoflagellate, were expressed in a bacterial expression system and their enzymatic activities were examined. We demonstrated 2-5A synthesizing activities of OASs from the marine sponge Tedania ignis, a representative of the phylogenetically oldest metazoan phylum (Porifera), from an invertebrate of the protostome lineage, the mollusk Mytilus californianus (Mollusca), and from a vertebrate species, a cartilaginous fish Leucoraja erinacea (Chordata). However, the expressed proteins from an amphibian, the salamander Ambystoma mexicanum (Chordata), and from a protozoan, the marine choanoflagellate Monosiga brevicollis (Choanozoa), did not show 2-5A synthesizing activity. Differently from other studied OASs, OAS from the marine sponge T. ignis was able to catalyze the formation of oligomers having both 2',5'- and 3',5'-phosphodiester linkages. Our data suggest that OASs from sponges and evolutionarily higher animals have similar activation mechanisms which still include different affinities and possibly different structural requirements for the activating RNAs. Considering their 2'- and 3'-specificities, sponge OASs could represent a link between evolutionarily earlier nucleotidyl transferases and 2'-specific OASs from higher animals. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  9. Integrated arrays of air-dielectric graphene transistors as transparent active-matrix pressure sensors for wide pressure ranges.

    Science.gov (United States)

    Shin, Sung-Ho; Ji, Sangyoon; Choi, Seiho; Pyo, Kyoung-Hee; Wan An, Byeong; Park, Jihun; Kim, Joohee; Kim, Ju-Young; Lee, Ki-Suk; Kwon, Soon-Yong; Heo, Jaeyeong; Park, Byong-Guk; Park, Jang-Ung

    2017-03-31

    Integrated electronic circuitries with pressure sensors have been extensively researched as a key component for emerging electronics applications such as electronic skins and health-monitoring devices. Although existing pressure sensors display high sensitivities, they can only be used for specific purposes due to the narrow range of detectable pressure (under tens of kPa) and the difficulty of forming highly integrated arrays. However, it is essential to develop tactile pressure sensors with a wide pressure range in order to use them for diverse application areas including medical diagnosis, robotics or automotive electronics. Here we report an unconventional approach for fabricating fully integrated active-matrix arrays of pressure-sensitive graphene transistors with air-dielectric layers simply formed by folding two opposing panels. Furthermore, this realizes a wide tactile pressure sensing range from 250 Pa to ∼3 MPa. Additionally, fabrication of pressure sensor arrays and transparent pressure sensors are demonstrated, suggesting their substantial promise as next-generation electronics.

  10. Evolutionary Design of Convolutional Neural Networks for Human Activity Recognition in Sensor-Rich Environments

    Science.gov (United States)

    2018-01-01

    Human activity recognition is a challenging problem for context-aware systems and applications. It is gaining interest due to the ubiquity of different sensor sources, wearable smart objects, ambient sensors, etc. This task is usually approached as a supervised machine learning problem, where a label is to be predicted given some input data, such as the signals retrieved from different sensors. For tackling the human activity recognition problem in sensor network environments, in this paper we propose the use of deep learning (convolutional neural networks) to perform activity recognition using the publicly available OPPORTUNITY dataset. Instead of manually choosing a suitable topology, we will let an evolutionary algorithm design the optimal topology in order to maximize the classification F1 score. After that, we will also explore the performance of committees of the models resulting from the evolutionary process. Results analysis indicates that the proposed model was able to perform activity recognition within a heterogeneous sensor network environment, achieving very high accuracies when tested with new sensor data. Based on all conducted experiments, the proposed neuroevolutionary system has proved to be able to systematically find a classification model which is capable of outperforming previous results reported in the state-of-the-art, showing that this approach is useful and improves upon previously manually-designed architectures. PMID:29690587

  11. Evolutionary Design of Convolutional Neural Networks for Human Activity Recognition in Sensor-Rich Environments

    Directory of Open Access Journals (Sweden)

    Alejandro Baldominos

    2018-04-01

    Full Text Available Human activity recognition is a challenging problem for context-aware systems and applications. It is gaining interest due to the ubiquity of different sensor sources, wearable smart objects, ambient sensors, etc. This task is usually approached as a supervised machine learning problem, where a label is to be predicted given some input data, such as the signals retrieved from different sensors. For tackling the human activity recognition problem in sensor network environments, in this paper we propose the use of deep learning (convolutional neural networks to perform activity recognition using the publicly available OPPORTUNITY dataset. Instead of manually choosing a suitable topology, we will let an evolutionary algorithm design the optimal topology in order to maximize the classification F1 score. After that, we will also explore the performance of committees of the models resulting from the evolutionary process. Results analysis indicates that the proposed model was able to perform activity recognition within a heterogeneous sensor network environment, achieving very high accuracies when tested with new sensor data. Based on all conducted experiments, the proposed neuroevolutionary system has proved to be able to systematically find a classification model which is capable of outperforming previous results reported in the state-of-the-art, showing that this approach is useful and improves upon previously manually-designed architectures.

  12. Evolutionary Design of Convolutional Neural Networks for Human Activity Recognition in Sensor-Rich Environments.

    Science.gov (United States)

    Baldominos, Alejandro; Saez, Yago; Isasi, Pedro

    2018-04-23

    Human activity recognition is a challenging problem for context-aware systems and applications. It is gaining interest due to the ubiquity of different sensor sources, wearable smart objects, ambient sensors, etc. This task is usually approached as a supervised machine learning problem, where a label is to be predicted given some input data, such as the signals retrieved from different sensors. For tackling the human activity recognition problem in sensor network environments, in this paper we propose the use of deep learning (convolutional neural networks) to perform activity recognition using the publicly available OPPORTUNITY dataset. Instead of manually choosing a suitable topology, we will let an evolutionary algorithm design the optimal topology in order to maximize the classification F1 score. After that, we will also explore the performance of committees of the models resulting from the evolutionary process. Results analysis indicates that the proposed model was able to perform activity recognition within a heterogeneous sensor network environment, achieving very high accuracies when tested with new sensor data. Based on all conducted experiments, the proposed neuroevolutionary system has proved to be able to systematically find a classification model which is capable of outperforming previous results reported in the state-of-the-art, showing that this approach is useful and improves upon previously manually-designed architectures.

  13. Development of a Smartphone Application to Measure Physical Activity Using Sensor-Assisted Self-Report

    Directory of Open Access Journals (Sweden)

    Genevieve Fridlund Dunton

    2014-02-01

    Full Text Available Introduction: Despite the known advantages of objective physical activity monitors (e.g., accelerometers, these devices have high rates of non-wear, which leads to missing data. Objective activity monitors are also unable to capture valuable contextual information about behavior. Adolescents recruited into physical activity surveillance and intervention studies will increasingly have smartphones, which are miniature computers with built-in motion sensors. Methods: This paper describes the design and development of a smartphone application (app called Mobile Teen that combines objective and self-report assessment strategies through (1 sensor-informed context-sensitive ecological momentary assessment (CS-EMA and (2 sensor-assisted end-of-day recall.Results: The Mobile Teen app uses the mobile phone’s built-in motion sensor to automatically detect likely bouts of phone non-wear, sedentary behavior, and physical activity. The app then uses transitions between these inferred states to trigger CS-EMA self-report surveys measuring the type, purpose, and context of activity in real time. The end of the day recall component of the Mobile Teen app allows users to interactively review and label their own physical activity data each evening using visual cues from automatically-detected major activity transitions from the phone’s built-in motions sensors. Major activity transitions are identified by the app, which cues the user to label that chunk, or period, of time using activity categories.Conclusions: Sensor-driven CS-EMA and end-of-day recall smartphone apps can be used to augment physical activity data collected by objective activity monitors, filling in gaps during non-wear bouts and providing additional real-time data on environmental, social, and emotional correlates of behavior. Smartphone apps such as these have potential for affordable deployment in large scale epidemiological and intervention studies.

  14. Front end optimization for the monolithic active pixel sensor of the ALICE Inner Tracking System upgrade

    International Nuclear Information System (INIS)

    Kim, D.; Rinella, G. Aglieri; Cavicchioli, C.; Hillemanns, H.; Hristozkov, S.; Junique, A.; Keil, M.; Kofarago, M.; Kugathasan, T.; Mager, M.; Chanlek, N.; Collu, A.; Degerli, Y.; Flouzat, C.; Guilloux, F.; Dorokhov, A.; Gajanana, D.; Gao, C.; Kwon, Y.; Lattuca, A.

    2016-01-01

    ALICE plans to replace its Inner Tracking System during the second long shut down of the LHC in 2019 with a new 10 m 2 tracker constructed entirely with monolithic active pixel sensors. The TowerJazz 180 nm CMOS imaging Sensor process has been selected to produce the sensor as it offers a deep pwell allowing full CMOS in-pixel circuitry and different starting materials. First full-scale prototypes have been fabricated and tested. Radiation tolerance has also been verified. In this paper the development of the charge sensitive front end and in particular its optimization for uniformity of charge threshold and time response will be presented

  15. Front end optimization for the monolithic active pixel sensor of the ALICE Inner Tracking System upgrade

    Science.gov (United States)

    Kim, D.; Aglieri Rinella, G.; Cavicchioli, C.; Chanlek, N.; Collu, A.; Degerli, Y.; Dorokhov, A.; Flouzat, C.; Gajanana, D.; Gao, C.; Guilloux, F.; Hillemanns, H.; Hristozkov, S.; Junique, A.; Keil, M.; Kofarago, M.; Kugathasan, T.; Kwon, Y.; Lattuca, A.; Mager, M.; Sielewicz, K. M.; Marin Tobon, C. A.; Marras, D.; Martinengo, P.; Mazza, G.; Mugnier, H.; Musa, L.; Pham, T. H.; Puggioni, C.; Reidt, F.; Riedler, P.; Rousset, J.; Siddhanta, S.; Snoeys, W.; Song, M.; Usai, G.; Van Hoorne, J. W.; Yang, P.

    2016-02-01

    ALICE plans to replace its Inner Tracking System during the second long shut down of the LHC in 2019 with a new 10 m2 tracker constructed entirely with monolithic active pixel sensors. The TowerJazz 180 nm CMOS imaging Sensor process has been selected to produce the sensor as it offers a deep pwell allowing full CMOS in-pixel circuitry and different starting materials. First full-scale prototypes have been fabricated and tested. Radiation tolerance has also been verified. In this paper the development of the charge sensitive front end and in particular its optimization for uniformity of charge threshold and time response will be presented.

  16. Front end optimization for the monolithic active pixel sensor of the ALICE Inner Tracking System upgrade

    OpenAIRE

    Kim, D; Rinella, G Aglieri; Cavicchioli, C; Chanlek, N; Collu, A; Degerli, Y; Dorokhov, A; Flouzat, C; Gajanana, D; Gao, C; Guilloux, F; Hillemanns, H; Hristozkov, S; Junique, A; Keil, M

    2016-01-01

    ALICE plans to replace its Inner Tracking System during the second long shut down of the LHC in 2019 with a new 10 m(2) tracker constructed entirely with monolithic active pixel sensors. The TowerJazz 180 nm CMOS imaging Sensor process has been selected to produce the sensor as it offers a deep pwell allowing full CMOS in-pixel circuitry and different starting materials. First full-scale prototypes have been fabricated and tested. Radiation tolerance has also been verified. In this paper the ...

  17. Sensitivity-Enhanced Wearable Active Voiceprint Sensor Based on Cellular Polypropylene Piezoelectret.

    Science.gov (United States)

    Li, Wenbo; Zhao, Sheng; Wu, Nan; Zhong, Junwen; Wang, Bo; Lin, Shizhe; Chen, Shuwen; Yuan, Fang; Jiang, Hulin; Xiao, Yongjun; Hu, Bin; Zhou, Jun

    2017-07-19

    Wearable active sensors have extensive applications in mobile biosensing and human-machine interaction but require good flexibility, high sensitivity, excellent stability, and self-powered feature. In this work, cellular polypropylene (PP) piezoelectret was chosen as the core material of a sensitivity-enhanced wearable active voiceprint sensor (SWAVS) to realize voiceprint recognition. By virtue of the dipole orientation control method, the air layers in the piezoelectret were efficiently utilized, and the current sensitivity was enhanced (from 1.98 pA/Hz to 5.81 pA/Hz at 115 dB). The SWAVS exhibited the superiorities of high sensitivity, accurate frequency response, and excellent stability. The voiceprint recognition system could make correct reactions to human voices by judging both the password and speaker. This study presented a voiceprint sensor with potential applications in noncontact biometric recognition and safety guarantee systems, promoting the progress of wearable sensor networks.

  18. Cloud Classification in Wide-Swath Passive Sensor Images Aided by Narrow-Swath Active Sensor Data

    Directory of Open Access Journals (Sweden)

    Hongxia Wang

    2018-05-01

    Full Text Available It is a challenge to distinguish between different cloud types because of the complexity and diversity of cloud coverage, which is a significant clutter source that impacts on target detection and identification from the images of space-based infrared sensors. In this paper, a novel strategy for cloud classification in wide-swath passive sensor images is developed, which is aided by narrow-swath active sensor data. The strategy consists of three steps, that is, the orbit registration, most matching donor pixel selection, and cloud type assignment for each recipient pixel. A new criterion for orbit registration is proposed so as to improve the matching accuracy. The most matching donor pixel is selected via the Euclidean distance and the square sum of the radiance relative differences between the recipient and the potential donor pixels. Each recipient pixel is then assigned a cloud type that corresponds to the most matching donor. The cloud classification of the Moderate Resolution Imaging Spectroradiometer (MODIS images is performed with the aid of the data from Cloud Profiling Radar (CPR. The results are compared with the CloudSat product 2B-CLDCLASS, as well as those that are obtained using the method of the International Satellite Cloud Climatology Project (ISCCP, which demonstrates the superior classification performance of the proposed strategy.

  19. Design and performance of an integrated ground and space sensor web for monitoring active volcanoes.

    Science.gov (United States)

    Lahusen, Richard; Song, Wenzhan; Kedar, Sharon; Shirazi, Behrooz; Chien, Steve; Doubleday, Joshua; Davies, Ashley; Webb, Frank; Dzurisin, Dan; Pallister, John

    2010-05-01

    An interdisciplinary team of computer, earth and space scientists collaborated to develop a sensor web system for rapid deployment at active volcanoes. The primary goals of this Optimized Autonomous Space In situ Sensorweb (OASIS) are to: 1) integrate complementary space and in situ (ground-based) elements into an interactive, autonomous sensor web; 2) advance sensor web power and communication resource management technology; and 3) enable scalability for seamless addition sensors and other satellites into the sensor web. This three-year project began with a rigorous multidisciplinary interchange that resulted in definition of system requirements to guide the design of the OASIS network and to achieve the stated project goals. Based on those guidelines, we have developed fully self-contained in situ nodes that integrate GPS, seismic, infrasonic and lightning (ash) detection sensors. The nodes in the wireless sensor network are linked to the ground control center through a mesh network that is highly optimized for remote geophysical monitoring. OASIS also features an autonomous bidirectional interaction between ground nodes and instruments on the EO-1 space platform through continuous analysis and messaging capabilities at the command and control center. Data from both the in situ sensors and satellite-borne hyperspectral imaging sensors stream into a common database for real-time visualization and analysis by earth scientists. We have successfully completed a field deployment of 15 nodes within the crater and on the flanks of Mount St. Helens, Washington. The demonstration that sensor web technology facilitates rapid network deployments and that we can achieve real-time continuous data acquisition. We are now optimizing component performance and improving user interaction for additional deployments at erupting volcanoes in 2010.

  20. Stretchable Active Matrix Temperature Sensor Array of Polyaniline Nanofibers for Electronic Skin.

    Science.gov (United States)

    Hong, Soo Yeong; Lee, Yong Hui; Park, Heun; Jin, Sang Woo; Jeong, Yu Ra; Yun, Junyeong; You, Ilhwan; Zi, Goangseup; Ha, Jeong Sook

    2016-02-03

    A stretchable polyaniline nanofiber temperature sensor array with an active matrix consisting of single-walled carbon nanotube thin-film transistors is demonstrated. The integrated temperature sensor array gives mechanical stability under biaxial stretching of 30%, and the resultant spatial temperature mapping does not show any mechanical or electrical degradation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. USING PASSIVE AND ACTIVE MULTISPECTRAL SENSORS ON THE CORRELATION WITH THE PHENOLOGICAL INDICES OF COTTON

    OpenAIRE

    Souza, Heloisa B.; Baio, Fabio H. R.; Neves, Danilo C.

    2017-01-01

    ABSTRACT: The investment in precision agriculture technologies has been growing as well the investment in vegetation index sensors with different types of data collection. This study aimed to evaluate the NDVI potential use obtained from passive and active multispectral sensors as phenological parameters indicator of cotton growth. The experiment was conducted in cultivated cotton fields during the harvest seasons of 2013/14 and 2014/15. The phenological variables analyzed in the field, were ...

  2. Optical Breath Gas Extravehicular Activity Sensor for the Advanced Portable Life Support System

    Science.gov (United States)

    Wood, William R.; Casias, Miguel E.; Pilgrim, Jeffrey S.; Chullen, Cinda; Campbell, Colin

    2016-01-01

    The infrared gas transducer used during extravehicular activity (EVA) in the extravehicular mobility unit (EMU) measures and reports the concentration of carbon dioxide (CO2) in the ventilation loop. It is nearing its end of life and there are a limited number remaining. Meanwhile, the next generation advanced portable life support system (PLSS) now being developed requires CO2 sensing technology with performance beyond that presently in use. A laser diode (LD) spectrometer based on wavelength modulation spectroscopy (WMS) is being developed to address both applications by Vista Photonics, Inc. Accommodation within space suits demands that optical sensors meet stringent size, weight, and power requirements. Version 1.0 devices were delivered to NASA Johnson Space Center (JSC) in 2011. The sensors incorporate a laser diode based CO2 channel that also includes an incidental water vapor (humidity) measurement. The prototypes are controlled digitally with a field-programmable gate array (FPGA)/microcontroller architecture. Version 2.0 devices with improved electronics and significantly reduced wetted volumes were delivered to JSC in 2012. A version 2.5 upgrade recently implemented wavelength stabilized operation, better humidity measurement, and much faster data analysis/reporting. A wholly reconfigured version 3.0 will maintain the demonstrated performance of earlier versions while being backwards compatible with the EMU and offering a radiation tolerant architecture.

  3. Should Cost-Effectiveness Analysis Include the Cost of Consumption Activities? AN Empirical Investigation.

    Science.gov (United States)

    Adarkwah, Charles Christian; Sadoghi, Amirhossein; Gandjour, Afschin

    2016-02-01

    There has been a debate on whether cost-effectiveness analysis should consider the cost of consumption and leisure time activities when using the quality-adjusted life year as a measure of health outcome under a societal perspective. The purpose of this study was to investigate whether the effects of ill health on consumptive activities are spontaneously considered in a health state valuation exercise and how much this matters. The survey enrolled patients with inflammatory bowel disease in Germany (n = 104). Patients were randomized to explicit and no explicit instruction for the consideration of consumption and leisure effects in a time trade-off (TTO) exercise. Explicit instruction to consider non-health-related utility in TTO exercises did not influence TTO scores. However, spontaneous consideration of non-health-related utility in patients without explicit instruction (60% of respondents) led to significantly lower TTO scores. Results suggest an inclusion of consumption costs in the numerator of the cost-effectiveness ratio, at least for those respondents who spontaneously consider non-health-related utility from treatment. Results also suggest that exercises eliciting health valuations from the general public may include a description of the impact of disease on consumptive activities. Copyright © 2015 John Wiley & Sons, Ltd.

  4. Passive radiation detection using optically active CMOS sensors

    Science.gov (United States)

    Dosiek, Luke; Schalk, Patrick D.

    2013-05-01

    Recently, there have been a number of small-scale and hobbyist successes in employing commodity CMOS-based camera sensors for radiation detection. For example, several smartphone applications initially developed for use in areas near the Fukushima nuclear disaster are capable of detecting radiation using a cell phone camera, provided opaque tape is placed over the lens. In all current useful implementations, it is required that the sensor not be exposed to visible light. We seek to build a system that does not have this restriction. While building such a system would require sophisticated signal processing, it would nevertheless provide great benefits. In addition to fulfilling their primary function of image capture, cameras would also be able to detect unknown radiation sources even when the danger is considered to be low or non-existent. By experimentally profiling the image artifacts generated by gamma ray and β particle impacts, algorithms are developed to identify the unique features of radiation exposure, while discarding optical interaction and thermal noise effects. Preliminary results focus on achieving this goal in a laboratory setting, without regard to integration time or computational complexity. However, future work will seek to address these additional issues.

  5. Low-Cost Sensor System Design for In-Home Physical Activity Tracking.

    Science.gov (United States)

    Nambiar, Siddhartha; Nikolaev, Alexander; Greene, Melissa; Cavuoto, Lora; Bisantz, Ann

    2016-01-01

    An aging and more sedentary population requires interventions aimed at monitoring physical activity, particularly within the home. This research uses simulation, optimization, and regression analyses to assess the feasibility of using a small number of sensors to track movement and infer physical activity levels of older adults. Based on activity data from the American Time Use Survey and assisted living apartment layouts, we determined that using three to four doorway sensors can be used to effectively capture a sufficient amount of movements in order to estimate activity. The research also identified preferred approaches for assigning sensor locations, evaluated the error magnitude inherent in the approach, and developed a methodology to identify which apartment layouts would be best suited for these technologies.

  6. Detection Thresholds of Falling Snow From Satellite-Borne Active and Passive Sensors

    Science.gov (United States)

    Skofronick-Jackson, Gail M.; Johnson, Benjamin T.; Munchak, S. Joseph

    2013-01-01

    There is an increased interest in detecting and estimating the amount of falling snow reaching the Earths surface in order to fully capture the global atmospheric water cycle. An initial step toward global spaceborne falling snow algorithms for current and future missions includes determining the thresholds of detection for various active and passive sensor channel configurations and falling snow events over land surfaces and lakes. In this paper, cloud resolving model simulations of lake effect and synoptic snow events were used to determine the minimum amount of snow (threshold) that could be detected by the following instruments: the W-band radar of CloudSat, Global Precipitation Measurement (GPM) Dual-Frequency Precipitation Radar (DPR)Ku- and Ka-bands, and the GPM Microwave Imager. Eleven different nonspherical snowflake shapes were used in the analysis. Notable results include the following: 1) The W-band radar has detection thresholds more than an order of magnitude lower than the future GPM radars; 2) the cloud structure macrophysics influences the thresholds of detection for passive channels (e.g., snow events with larger ice water paths and thicker clouds are easier to detect); 3) the snowflake microphysics (mainly shape and density)plays a large role in the detection threshold for active and passive instruments; 4) with reasonable assumptions, the passive 166-GHz channel has detection threshold values comparable to those of the GPM DPR Ku- and Ka-band radars with approximately 0.05 g *m(exp -3) detected at the surface, or an approximately 0.5-1.0-mm * h(exp -1) melted snow rate. This paper provides information on the light snowfall events missed by the sensors and not captured in global estimates.

  7. Recognition of Walking Activities Using Wireless Inertial and Orientation Sensors: A Performance Evaluation

    NARCIS (Netherlands)

    Yalçin, Ç.; Marin Perianu, Mihai; Marin Perianu, Raluca; Havinga, Paul J.M.; Augusto, J.C.

    In this paper, we evaluate experimentally several methods for recognizing walking activities using on-body wireless nodes equipped with inertial and orientation sensors. The walking activities (walking on flat surfaces, uphill and downhill, upstairs and downstairs) are selected by healthcare experts

  8. Modular Bayesian Networks with Low-Power Wearable Sensors for Recognizing Eating Activities.

    Science.gov (United States)

    Kim, Kee-Hoon; Cho, Sung-Bae

    2017-12-11

    Recently, recognizing a user's daily activity using a smartphone and wearable sensors has become a popular issue. However, in contrast with the ideal definition of an experiment, there could be numerous complex activities in real life with respect to its various background and contexts: time, space, age, culture, and so on. Recognizing these complex activities with limited low-power sensors, considering the power and memory constraints of the wearable environment and the user's obtrusiveness at once is not an easy problem, although it is very crucial for the activity recognizer to be practically useful. In this paper, we recognize activity of eating, which is one of the most typical examples of a complex activity, using only daily low-power mobile and wearable sensors. To organize the related contexts systemically, we have constructed the context model based on activity theory and the "Five W's", and propose a Bayesian network with 88 nodes to predict uncertain contexts probabilistically. The structure of the proposed Bayesian network is designed by a modular and tree-structured approach to reduce the time complexity and increase the scalability. To evaluate the proposed method, we collected the data with 10 different activities from 25 volunteers of various ages, occupations, and jobs, and have obtained 79.71% accuracy, which outperforms other conventional classifiers by 7.54-14.4%. Analyses of the results showed that our probabilistic approach could also give approximate results even when one of contexts or sensor values has a very heterogeneous pattern or is missing.

  9. Optimization strategy for actuator and sensor placement in active structural acoustic control

    NARCIS (Netherlands)

    Oude nijhuis, M.H.H.; de Boer, Andries

    2003-01-01

    In active structural acoustic control the goal is to reduce the sound radiation of a structure by means of changing the vibrational behaviour of that structure. The performance of such an active control system is to a large extent determined by the locations of the actuators and sensors. In this

  10. A Pattern Mining Approach to Sensor-based Human Activity Recognition

    DEFF Research Database (Denmark)

    Gu, Tao; Wang, Liang; Wu, Zhanqing

    2011-01-01

    Recognizing human activities from sensor readings has recently attracted much research interest in pervasive computing due to its potential in many applications such as assistive living and healthcare. This task is particularly challenging because human activities are often performed in not only...

  11. HACMAC: A reliable human activity-based medium access control for implantable body sensor networks

    NARCIS (Netherlands)

    Karuppiah Ramachandran, Vignesh Raja; Havinga, Paul J.M.; Meratnia, Nirvana

    Chronic care is an eminent application of implantable body sensor networks (IBSN). Performing physical activities such as walking, running, and sitting is unavoidable during the long-term monitoring of chronic-care patients. These physical activities cripple the radio frequency (RF) signal between

  12. Performance of a novel wafer scale CMOS active pixel sensor for bio-medical imaging

    International Nuclear Information System (INIS)

    Esposito, M; Evans, P M; Wells, K; Anaxagoras, T; Konstantinidis, A C; Zheng, Y; Speller, R D; Allinson, N M

    2014-01-01

    Recently CMOS active pixels sensors (APSs) have become a valuable alternative to amorphous silicon and selenium flat panel imagers (FPIs) in bio-medical imaging applications. CMOS APSs can now be scaled up to the standard 20 cm diameter wafer size by means of a reticle stitching block process. However, despite wafer scale CMOS APS being monolithic, sources of non-uniformity of response and regional variations can persist representing a significant challenge for wafer scale sensor response. Non-uniformity of stitched sensors can arise from a number of factors related to the manufacturing process, including variation of amplification, variation between readout components, wafer defects and process variations across the wafer due to manufacturing processes. This paper reports on an investigation into the spatial non-uniformity and regional variations of a wafer scale stitched CMOS APS. For the first time a per-pixel analysis of the electro-optical performance of a wafer CMOS APS is presented, to address inhomogeneity issues arising from the stitching techniques used to manufacture wafer scale sensors. A complete model of the signal generation in the pixel array has been provided and proved capable of accounting for noise and gain variations across the pixel array. This novel analysis leads to readout noise and conversion gain being evaluated at pixel level, stitching block level and in regions of interest, resulting in a coefficient of variation ⩽1.9%. The uniformity of the image quality performance has been further investigated in a typical x-ray application, i.e. mammography, showing a uniformity in terms of CNR among the highest when compared with mammography detectors commonly used in clinical practice. Finally, in order to compare the detection capability of this novel APS with the technology currently used (i.e. FPIs), theoretical evaluation of the detection quantum efficiency (DQE) at zero-frequency has been performed, resulting in a higher DQE for this

  13. Performance of a novel wafer scale CMOS active pixel sensor for bio-medical imaging.

    Science.gov (United States)

    Esposito, M; Anaxagoras, T; Konstantinidis, A C; Zheng, Y; Speller, R D; Evans, P M; Allinson, N M; Wells, K

    2014-07-07

    Recently CMOS active pixels sensors (APSs) have become a valuable alternative to amorphous silicon and selenium flat panel imagers (FPIs) in bio-medical imaging applications. CMOS APSs can now be scaled up to the standard 20 cm diameter wafer size by means of a reticle stitching block process. However, despite wafer scale CMOS APS being monolithic, sources of non-uniformity of response and regional variations can persist representing a significant challenge for wafer scale sensor response. Non-uniformity of stitched sensors can arise from a number of factors related to the manufacturing process, including variation of amplification, variation between readout components, wafer defects and process variations across the wafer due to manufacturing processes. This paper reports on an investigation into the spatial non-uniformity and regional variations of a wafer scale stitched CMOS APS. For the first time a per-pixel analysis of the electro-optical performance of a wafer CMOS APS is presented, to address inhomogeneity issues arising from the stitching techniques used to manufacture wafer scale sensors. A complete model of the signal generation in the pixel array has been provided and proved capable of accounting for noise and gain variations across the pixel array. This novel analysis leads to readout noise and conversion gain being evaluated at pixel level, stitching block level and in regions of interest, resulting in a coefficient of variation ⩽1.9%. The uniformity of the image quality performance has been further investigated in a typical x-ray application, i.e. mammography, showing a uniformity in terms of CNR among the highest when compared with mammography detectors commonly used in clinical practice. Finally, in order to compare the detection capability of this novel APS with the technology currently used (i.e. FPIs), theoretical evaluation of the detection quantum efficiency (DQE) at zero-frequency has been performed, resulting in a higher DQE for this

  14. Piezoelectric Active Humidity Sensors Based on Lead-Free NaNbO3 Piezoelectric Nanofibers

    Directory of Open Access Journals (Sweden)

    Li Gu

    2016-06-01

    Full Text Available The development of micro-/nano-scaled energy harvesters and the self-powered sensor system has attracted great attention due to the miniaturization and integration of the micro-device. In this work, lead-free NaNbO3 piezoelectric nanofibers with a monoclinic perovskite structure were synthesized by the far-field electrospinning method. The flexible active humidity sensors were fabricated by transferring the nanofibers from silicon to a soft polymer substrate. The sensors exhibited outstanding piezoelectric energy-harvesting performance with output voltage up to 2 V during the vibration process. The output voltage generated by the NaNbO3 sensors exhibited a negative correlation with the environmental humidity varying from 5% to 80%, where the peak-to-peak value of the output voltage generated by the sensors decreased from 0.40 to 0.07 V. The sensor also exhibited a short response time, good selectively against ethanol steam, and great temperature stability. The piezoelectric active humidity sensing property could be attributed to the increased leakage current in the NaNbO3 nanofibers, which was generated due to proton hopping among the H3O+ groups in the absorbed H2O layers under the driving force of the piezoelectric potential.

  15. Photon small-field measurements with a CMOS active pixel sensor.

    Science.gov (United States)

    Spang, F Jiménez; Rosenberg, I; Hedin, E; Royle, G

    2015-06-07

    In this work the dosimetric performance of CMOS active pixel sensors for the measurement of small photon beams is presented. The detector used consisted of an array of 520  × 520 pixels on a 25 µm pitch. Dosimetric parameters measured with this sensor were compared with data collected with an ionization chamber, a film detector and GEANT4 Monte Carlo simulations. The sensor performance for beam profiles measurements was evaluated for field sizes of 0.5  × 0.5 cm(2). The high spatial resolution achieved with this sensor allowed the accurate measurement of profiles, beam penumbrae and field size under lateral electronic disequilibrium. Field size and penumbrae agreed within 5.4% and 2.2% respectively with film measurements. Agreements with ionization chambers better than 1.0% were obtained when measuring tissue-phantom ratios. Output factor measurements were in good agreement with ionization chamber and Monte Carlo simulation. The data obtained from this imaging sensor can be easily analyzed to extract dosimetric information. The results presented in this work are promising for the development and implementation of CMOS active pixel sensors for dosimetry applications.

  16. Noise Parameters of CW Radar Sensors Used in Active Defense Systems

    Directory of Open Access Journals (Sweden)

    V. Jenik

    2012-06-01

    Full Text Available Active defense represents an innovative way of protecting military vehicles. It is based on the employment of a set of radar sensors which detect an approaching threat missile and activate a suitable counter-measure. Since the radar sensors are supposed to detect flying missiles very fast and, at the same time, distinguish them from stationary or slow-moving objects, CW Doppler radar sensors can be employed with a benefit. The submitted article deals with a complex noise analysis of this type of sensors. The analysis considers the noise of linear and quasi-linear RF components, phase-noise of the local oscillator as well as the noise of low-frequency circuits. Since the incidence of the phase-noise depends strongly upon the time delay between the reference and the cross-talked signals, a new method of measuring noise parameters utilizing a reflecting wall has been developed and verified. The achieved results confirm potentially high influence of the phase-noise on the noise parameters of the mentioned type of radar sensors. Obtained results can be used for the analysis of noise parameters of the similar but even more complex sensors.

  17. Characteristics of an β-N-Acetylhexosaminidase from Bacillus sp. CH11, Including its Transglycosylation Activity.

    Science.gov (United States)

    Kurakake, Masahiro; Amai, Yukari; Konishi, Mizuki; Ikehira, Kaho

    2018-04-06

    β-N-Acetylhexosaminidase was identified from Bacillus sp. CH11 and found to have relatively high transferring activity. In this study, its enzymatic properties and transglycosylation activity including its acceptor specificity were investigated. Its molecular weight was estimated to be 90 kDa by SDS-PAGE and its optimal pH was approximately 7 with good stability from pH 6 to 8. Its optimal temperature was 40 °C, and its activity was stable at temperatures of up to 40 °C. To analyze its acceptor specificity for transglycosylation, N, N'-diacetylchitobiose was used as a donor substrate and alcohols, sugar alcohols, sugars and polyphenols were used as acceptors. Dialcohols, which have 2 hydroxyl groups on the outside of the carbon chains, were good acceptors. The molecular size of the acceptor did not influence the transglycosylation up to at least 1,5-pentanediol (carbon number: C5). Glycerin (C3), erythritol (C4), and xylitol (C5), all small molecular weight sugar alcohols, had high acceptor specificity. Transglycosylation to mono- and disaccharides and polyphenols was not observed except for L-fucose. For the β-N-acetylhexosaminidase-catalyzed transglycosylation of chitin oligosaccharides and xylitol, the transfer product was identified as 1-O-β-D-N-acetylglucosaminyl xylitol. The optimal ratio of xylitol was 24% to 2% N, N'-diacetylchitobiose and 226 mg per 1 g N, N'-diacetylchitobiose was produced. CH11 β-N-acetylhexosaminidase efficiently produced 1-O-β-D-N-acetylglucosaminyl xylitol via transglycosylation. The new transfer products including 1-O-β-D-N-acetylglucosaminyl xylitol are attractive compounds for their potential physiological functions. 1-O-β-D-N-Acetylglucosaminyl xylitol was produced effectively from chitin-oligosaccharides and xylitol by β-N-acetylhexosaminidase from Bacillus sp. CH11. This enzyme may be useful for the development of food materials for health-related applications such as oligosaccharides with intestinal functions and

  18. IR Sensor Synchronizing Active Shutter Glasses for 3D HDTV with Flexible Liquid Crystal Lenses

    Directory of Open Access Journals (Sweden)

    Jeong In Han

    2013-12-01

    Full Text Available IR sensor synchronizing active shutter glasses for three-dimensional high definition television (3D HDTV were developed using a flexible liquid crystal (FLC lens. The FLC lens was made on a polycarbonate (PC substrate using conventional liquid crystal display (LCD processes. The flexible liquid crystal lens displayed a maximum transmission of 32% and total response time of 2.56 ms. The transmittance, the contrast ratio and the response time of the flexible liquid crystal lens were superior to those of glass liquid crystal lenses. Microcontroller unit and drivers were developed as part of a reception module with power supply for the IR sensor synchronizing active shutter glasses with the flexible liquid crystal lens prototypes. IR sensor synchronizing active shutter glasses for 3D HDTV with flexible liquid crystal lenses produced excellent 3D images viewing characteristics.

  19. Gas sensor

    International Nuclear Information System (INIS)

    Dorogan, V.; Korotchenkov, Gh.; Vieru, T.; Prodan, I.

    2003-01-01

    The invention relates to the gas sensors on base of metal-oxide films (SnO, InO), which may be used for enviromental control, in the fireextinguishing systema etc. The gas includes an insulating substrate, an active layer, a resistive layer with ohmic contacts. The resistive layer has two or more regions with dofferent resistances , and on the active layer are two or more pairs of ohmic contacts

  20. Simultaneous Activation of Iron- and Thiol-Based Sensor-Regulator Systems by Redox-Active Compounds.

    Science.gov (United States)

    Lee, Kang-Lok; Yoo, Ji-Sun; Oh, Gyeong-Seok; Singh, Atul K; Roe, Jung-Hye

    2017-01-01

    Bacteria in natural habitats are exposed to myriad redox-active compounds (RACs), which include producers of reactive oxygen species (ROS) and reactive electrophile species (RES) that alkylate or oxidize thiols. RACs can induce oxidative stress in cells and activate response pathways by modulating the activity of sensitive regulators. However, the effect of a certain compound on the cell has been investigated primarily with respect to a specific regulatory pathway. Since a single compound can exert multiple chemical effects in the cell, its effect can be better understood by time-course monitoring of multiple sensitive regulatory pathways that the compound induces. We investigated the effect of representative RACs by monitoring the activity of three sensor-regulators in the model actinobacterium Streptomyces coelicolor ; SoxR that senses reactive compounds directly through oxidation of its [2Fe-2S] cluster, CatR/PerR that senses peroxides through bound iron, and an anti-sigma factor RsrA that senses RES via disulfide formation. The time course and magnitude of induction of their target transcripts were monitored to predict the chemical activities of each compound in S. coelicolor . Phenazine methosulfate (PMS) was found to be an effective RAC that directly activated SoxR and an effective ROS-producer that induced CatR/PerR with little thiol-perturbing activity. p -Benzoquinone was an effective RAC that directly activated SoxR, with slower ROS-producing activity, and an effective RES that induced the RsrA-SigR system. Plumbagin was an effective RAC that activated SoxR, an effective ROS-producer, and a less agile but effective RES. Diamide was an RES that effectively formed disulfides and a weak RAC that activated SoxR. Monobromobimane was a moderately effective RES and a slow producer of ROS. Interestingly, benzoquinone induced the SigR system by forming adducts on cysteine thiols in RsrA, revealing a new pathway to modulate RsrA activity. Overall, this study showed

  1. Fluorogenic MMP activity assay for plasma including MMPs complexed to α2-macroglobulin

    NARCIS (Netherlands)

    Beekman, B.; Drijfhout, J.W.; Ronday, H.K.; TeKoppele, J.M.

    1999-01-01

    Elevated MMP activities are implicated in tissue degradation in, e.g., arthritis and cancer. The present study was designed to measure MMP enzyme activity in plasma. Free active MMP is unlikely to be present in plasma: upon entering the circulation, active MMP is expected to be captured by the

  2. Active vibration reduction by optimally placed sensors and actuators with application to stiffened plates by beams

    International Nuclear Information System (INIS)

    Daraji, A H; Hale, J M

    2014-01-01

    This study concerns new investigation of active vibration reduction of a stiffened plate bonded with discrete sensor/actuator pairs located optimally using genetic algorithms based on a developed finite element modeling. An isotropic plate element stiffened by a number of beam elements on its edges and having a piezoelectric sensor and actuator pair bonded to its surfaces is modeled using the finite element method and Hamilton’s principle, taking into account the effects of piezoelectric mass, stiffness and electromechanical coupling. The modeling is based on the first order shear deformation theory taking into account the effects of bending, membrane and shear deformation for the plate, the stiffening beam and the piezoelectric patches. A Matlab finite element program has been built for the stiffened plate model and verified with ANSYS and also experimentally. Optimal placement of ten piezoelectric sensor/actuator pairs and optimal feedback gain for active vibration reduction are investigated for a plate stiffened by two beams arranged in the form of a cross. The genetic algorithm was set up for optimization of sensor/actuator placement and feedback gain based on the minimization of the optimal linear quadratic index as an objective function to suppress the first six modes of vibration. Comparison study is presented for active vibration reduction of a square cantilever plate stiffened by crossed beams with two sensor/actuator configurations: firstly, ten piezoelectric sensor/actuator pairs are located in optimal positions; secondly, a piezoelectric layer of single sensor/actuator pair covering the whole of the stiffened plate as a SISO system. (paper)

  3. Chemical Sensor Platform for Non-Invasive Monitoring of Activity and Dehydration

    Directory of Open Access Journals (Sweden)

    Dmitry Solovei

    2015-01-01

    Full Text Available A non-invasive solution for monitoring of the activity and dehydration of organisms is proposed in the work. For this purpose, a wireless standalone chemical sensor platform using two separate measurement techniques has been developed. The first approach for activity monitoring is based on humidity measurement. Our solution uses new humidity sensor based on a nanostructured TiO2 surface for sweat rate monitoring. The second technique is based on monitoring of potassium concentration in urine. High level of potassium concentration denotes clear occurrence of dehydration. Furthermore, a Wireless Body Area Network (WBAN was developed for this sensor platform to manage data transfer among devices and the internet. The WBAN coordinator controls the sensor devices and collects and stores the measured data. The collected data is particular to individuals and can be shared with physicians, emergency systems or athletes’ coaches. Long-time monitoring of activity and potassium concentration in urine can help maintain the appropriate water intake of elderly people or athletes and to send warning signals in the case of near dehydration. The created sensor system was calibrated and tested in laboratory and real conditions as well. The measurement results are discussed.

  4. A Comprehensive Analysis on Wearable Acceleration Sensors in Human Activity Recognition

    Directory of Open Access Journals (Sweden)

    Majid Janidarmian

    2017-03-01

    Full Text Available Sensor-based motion recognition integrates the emerging area of wearable sensors with novel machine learning techniques to make sense of low-level sensor data and provide rich contextual information in a real-life application. Although Human Activity Recognition (HAR problem has been drawing the attention of researchers, it is still a subject of much debate due to the diverse nature of human activities and their tracking methods. Finding the best predictive model in this problem while considering different sources of heterogeneities can be very difficult to analyze theoretically, which stresses the need of an experimental study. Therefore, in this paper, we first create the most complete dataset, focusing on accelerometer sensors, with various sources of heterogeneities. We then conduct an extensive analysis on feature representations and classification techniques (the most comprehensive comparison yet with 293 classifiers for activity recognition. Principal component analysis is applied to reduce the feature vector dimension while keeping essential information. The average classification accuracy of eight sensor positions is reported to be 96.44% ± 1.62% with 10-fold evaluation, whereas accuracy of 79.92% ± 9.68% is reached in the subject-independent evaluation. This study presents significant evidence that we can build predictive models for HAR problem under more realistic conditions, and still achieve highly accurate results.

  5. A Comprehensive Analysis on Wearable Acceleration Sensors in Human Activity Recognition.

    Science.gov (United States)

    Janidarmian, Majid; Roshan Fekr, Atena; Radecka, Katarzyna; Zilic, Zeljko

    2017-03-07

    Sensor-based motion recognition integrates the emerging area of wearable sensors with novel machine learning techniques to make sense of low-level sensor data and provide rich contextual information in a real-life application. Although Human Activity Recognition (HAR) problem has been drawing the attention of researchers, it is still a subject of much debate due to the diverse nature of human activities and their tracking methods. Finding the best predictive model in this problem while considering different sources of heterogeneities can be very difficult to analyze theoretically, which stresses the need of an experimental study. Therefore, in this paper, we first create the most complete dataset, focusing on accelerometer sensors, with various sources of heterogeneities. We then conduct an extensive analysis on feature representations and classification techniques (the most comprehensive comparison yet with 293 classifiers) for activity recognition. Principal component analysis is applied to reduce the feature vector dimension while keeping essential information. The average classification accuracy of eight sensor positions is reported to be 96.44% ± 1.62% with 10-fold evaluation, whereas accuracy of 79.92% ± 9.68% is reached in the subject-independent evaluation. This study presents significant evidence that we can build predictive models for HAR problem under more realistic conditions, and still achieve highly accurate results.

  6. Bio-Inspired Carbon Monoxide Sensors with Voltage-Activated Sensitivity

    KAUST Repository

    Savagatrup, Suchol

    2017-09-27

    Carbon monoxide (CO) outcompetes oxygen when binding to the iron center of hemeproteins, leading to a reduction in blood oxygen level and acute poisoning. Harvesting the strong specific interaction between CO and the iron porphyrin provides a highly selective and customizable sensor. We report the development of chemiresistive sensors with voltage-activated sensitivity for the detection of CO comprising iron porphyrin and functionalized single-walled carbon nanotubes (F-SWCNTs). Modulation of the gate voltage offers a predicted extra dimension for sensing. Specifically, the sensors show a significant increase in sensitivity toward CO when negative gate voltage is applied. The dosimetric sensors are selective to ppm levels of CO and functional in air. UV/Vis spectroscopy, differential pulse voltammetry, and density functional theory reveal that the in situ reduction of FeIII to FeII enhances the interaction between the F-SWCNTs and CO. Our results illustrate a new mode of sensors wherein redox active recognition units are voltage-activated to give enhanced and highly specific responses.

  7. Evaluation of a Microbial Sensor as a Tool for Antimicrobial Activity Test of Cosmetic Preservatives.

    Science.gov (United States)

    Gomyo, Hideyuki; Ookawa, Masaki; Oshibuchi, Kota; Sugamura, Yuriko; Hosokawa, Masahito; Shionoiri, Nozomi; Maeda, Yoshiaki; Matsunaga, Tadashi; Tanaka, Tsuyoshi

    2015-01-01

    For high-throughput screening of novel cosmetic preservatives, a rapid and simple assay to evaluate the antimicrobial activities should be developed because the conventional agar dilution method is time-consuming and labor-intensive. To address this issue, we evaluated a microbial sensor as a tool for rapid antimicrobial activity testing. The sensor consists of an oxygen electrode and a filter membrane that holds the test microorganisms, Staphylococcus aureus and Candida albicans. The antimicrobial activity of the tested cosmetic preservative was evaluated by measuring the current increases corresponding to the decreases in oxygen consumption in the microbial respiration. The current increases detected by the sensor showed positive correlation to the concentrations of two commercially used preservatives, chlorphenesin and 2-phenoxyethanol. The same tendency was also observed when a model cosmetic product was used as a preservative solvent, indicating the feasibility in practical use. Furthermore, the microbial sensor and microfluidic flow-cell was assembled to achieve sequential measurements. The sensor system presented in this study could be useful in large-scale screening experiments.

  8. Fault Diagnosis Based on Chemical Sensor Data with an Active Deep Neural Network.

    Science.gov (United States)

    Jiang, Peng; Hu, Zhixin; Liu, Jun; Yu, Shanen; Wu, Feng

    2016-10-13

    Big sensor data provide significant potential for chemical fault diagnosis, which involves the baseline values of security, stability and reliability in chemical processes. A deep neural network (DNN) with novel active learning for inducing chemical fault diagnosis is presented in this study. It is a method using large amount of chemical sensor data, which is a combination of deep learning and active learning criterion to target the difficulty of consecutive fault diagnosis. DNN with deep architectures, instead of shallow ones, could be developed through deep learning to learn a suitable feature representation from raw sensor data in an unsupervised manner using stacked denoising auto-encoder (SDAE) and work through a layer-by-layer successive learning process. The features are added to the top Softmax regression layer to construct the discriminative fault characteristics for diagnosis in a supervised manner. Considering the expensive and time consuming labeling of sensor data in chemical applications, in contrast to the available methods, we employ a novel active learning criterion for the particularity of chemical processes, which is a combination of Best vs. Second Best criterion (BvSB) and a Lowest False Positive criterion (LFP), for further fine-tuning of diagnosis model in an active manner rather than passive manner. That is, we allow models to rank the most informative sensor data to be labeled for updating the DNN parameters during the interaction phase. The effectiveness of the proposed method is validated in two well-known industrial datasets. Results indicate that the proposed method can obtain superior diagnosis accuracy and provide significant performance improvement in accuracy and false positive rate with less labeled chemical sensor data by further active learning compared with existing methods.

  9. Fault Diagnosis Based on Chemical Sensor Data with an Active Deep Neural Network

    Science.gov (United States)

    Jiang, Peng; Hu, Zhixin; Liu, Jun; Yu, Shanen; Wu, Feng

    2016-01-01

    Big sensor data provide significant potential for chemical fault diagnosis, which involves the baseline values of security, stability and reliability in chemical processes. A deep neural network (DNN) with novel active learning for inducing chemical fault diagnosis is presented in this study. It is a method using large amount of chemical sensor data, which is a combination of deep learning and active learning criterion to target the difficulty of consecutive fault diagnosis. DNN with deep architectures, instead of shallow ones, could be developed through deep learning to learn a suitable feature representation from raw sensor data in an unsupervised manner using stacked denoising auto-encoder (SDAE) and work through a layer-by-layer successive learning process. The features are added to the top Softmax regression layer to construct the discriminative fault characteristics for diagnosis in a supervised manner. Considering the expensive and time consuming labeling of sensor data in chemical applications, in contrast to the available methods, we employ a novel active learning criterion for the particularity of chemical processes, which is a combination of Best vs. Second Best criterion (BvSB) and a Lowest False Positive criterion (LFP), for further fine-tuning of diagnosis model in an active manner rather than passive manner. That is, we allow models to rank the most informative sensor data to be labeled for updating the DNN parameters during the interaction phase. The effectiveness of the proposed method is validated in two well-known industrial datasets. Results indicate that the proposed method can obtain superior diagnosis accuracy and provide significant performance improvement in accuracy and false positive rate with less labeled chemical sensor data by further active learning compared with existing methods. PMID:27754386

  10. Fault Diagnosis Based on Chemical Sensor Data with an Active Deep Neural Network

    Directory of Open Access Journals (Sweden)

    Peng Jiang

    2016-10-01

    Full Text Available Big sensor data provide significant potential for chemical fault diagnosis, which involves the baseline values of security, stability and reliability in chemical processes. A deep neural network (DNN with novel active learning for inducing chemical fault diagnosis is presented in this study. It is a method using large amount of chemical sensor data, which is a combination of deep learning and active learning criterion to target the difficulty of consecutive fault diagnosis. DNN with deep architectures, instead of shallow ones, could be developed through deep learning to learn a suitable feature representation from raw sensor data in an unsupervised manner using stacked denoising auto-encoder (SDAE and work through a layer-by-layer successive learning process. The features are added to the top Softmax regression layer to construct the discriminative fault characteristics for diagnosis in a supervised manner. Considering the expensive and time consuming labeling of sensor data in chemical applications, in contrast to the available methods, we employ a novel active learning criterion for the particularity of chemical processes, which is a combination of Best vs. Second Best criterion (BvSB and a Lowest False Positive criterion (LFP, for further fine-tuning of diagnosis model in an active manner rather than passive manner. That is, we allow models to rank the most informative sensor data to be labeled for updating the DNN parameters during the interaction phase. The effectiveness of the proposed method is validated in two well-known industrial datasets. Results indicate that the proposed method can obtain superior diagnosis accuracy and provide significant performance improvement in accuracy and false positive rate with less labeled chemical sensor data by further active learning compared with existing methods.

  11. Sensors for the Senses: Meaning-making via self-active entertainment experiences

    Directory of Open Access Journals (Sweden)

    Anthony Brooks

    2015-08-01

    Full Text Available In his ACM Computers in Entertainment article, titled "Artist and Audience: Emerging the Nano-entertainment experience", the author posited on how Inhabited Information Spaces, created as core catalyst of research, may be questioned as a multisensory future virtual work of art. This themed Human-Computer Interaction for Entertainment contribution for the EAI INTETAIN 2015 conference builds upon the earlier work by questioning meaning making from such self-active entertainment experiences. Contextually, self-active relates to actor empowerment via ICT, whilst entertainment refers to HCI paradigms that are fun, engaging, and enjoyable. Conceptualizing, designing and realizing alternative digital media entertainment situations in stage performance, interactive installations and exhibitions at leading Museums for Modern Art, National and International major events, contributed to development of a sensor-based system conceived as a platform to investigate meaning making having societal impact beyond art. The system involves arrays of selectable sensor profiles mixed and matched according to requirements. Sensing of human input can be through worn (biosignal e.g. EEG, ECG, EMG, GSR, held, and/or non-worn sensors (volumetric, linear and planar interface profiles. Mapping of sourced human data is to a variety of digital content including art-based (music making, digital painting, lighting effects, video games, Virtual Reality and robotic devices. System adaptability promotes participant profile matching e.g. according to desired outcome. All ages and abilities are potential users. Preceding the commonly known camera-based game controllers such as EyeToy, Wii, and Kinect; the SoundScapes Virtual Interactive Space system has been used in institutes, hospitals and clinics to empower people with impairment to unconsciously push their limits of functionality via creative and playful expression. Rehabilitation is less mundane and boring, where variety of ICT

  12. Translating neuronal activity at the synapse: presynaptic calcium sensors in short-term plasticity

    Directory of Open Access Journals (Sweden)

    Arthur P.H. De Jong

    2014-10-01

    Full Text Available The complex manner in which patterns of presynaptic neural activity are translated into short-term plasticity (STP suggests the existence of multiple presynaptic calcium (Ca2+ sensors, which regulate the amplitude and time-course of STP and are the focus of this review. We describe two canonical Ca2+-binding protein domains (C2 domains and EF-hands and define criteria that need to be met for a protein to qualify as a Ca2+ sensor mediating STP. With these criteria in mind, we discuss various forms of STP and identify established and putative Ca2+ sensors. We find that despite the multitude of proposed sensors, only three are well established in STP: Munc13, protein kinase C and synaptotagmin-7. For putative sensors, we pinpoint open questions and potential pitfalls. Finally, we discuss how the molecular properties and modes of action of Ca2+ sensors can explain their differential involvement in STP and shape net synaptic output.

  13. Measuring Outcomes in Adult Weight Loss Studies That Include Diet and Physical Activity: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Rachel A. Millstein

    2014-01-01

    Full Text Available Background. Measuring success of obesity interventions is critical. Several methods measure weight loss outcomes but there is no consensus on best practices. This systematic review evaluates relevant outcomes (weight loss, BMI, % body fat, and fat mass to determine which might be the best indicator(s of success. Methods. Eligible articles described adult weight loss interventions that included diet and physical activity and a measure of weight or BMI change and body composition change. Results. 28 full-text articles met inclusion criteria. Subjects, settings, intervention lengths, and intensities varied. All studies measured body weight (−2.9 to −17.3 kg, 9 studies measured BMI (−1.1 to −5.1 kg/m2, 20 studies measured % body fat (−0.7 to −10.2%, and 22 studies measured fat mass (−0.9 to −14.9 kg. All studies found agreement between weight or BMI and body fat mass or body fat % decreases, though there were discrepancies in degree of significance between measures. Conclusions. Nearly all weight or BMI and body composition measures agreed. Since body fat is the most metabolically harmful tissue type, it may be a more meaningful measure of health change. Future studies should consider primarily measuring % body fat, rather than or in addition to weight or BMI.

  14. Performance of cement solidification with barium for high activity liquid waste including sulphate

    International Nuclear Information System (INIS)

    Waki, Toshikazu; Yamada, Motoyuki; Horikawa, Yoshihiko; Kaneko, Masaaki; Saso, Michitaka; Haruguchi, Yoshiko; Yamashita, Yu; Sakai, Hitoshi

    2009-01-01

    The target liquid waste to be solidified is generated from PWR primary loop spent resin treatment with sulphate acid, so, its main constituent is sodium sulphate and the activity of this liquid is relatively high. Waste form of this liquid waste is considered to be a candidate for the subsurface disposal. The disposed waste including sulphate is anticipated to rise a concentration of sulphate ion in the ground water around the disposal facility and it may cause degradation of materials such as cement and bentonite layer and comprise the disposal facility. There could be two approaches to avoid this problem, the strong design of the disposal facility and the minimization of sulphaste ion migration from the solidified waste. In this study, the latter approach was examined. In order to keep the low concentration of sulphate ion in the ground water, it is effective to make barium sulphate by adding barium compound into the liquid waste in solidification. However, adding equivalent amount of barium compound with sulphate ion causes difficulty of mixing, because production of barium sulphate causes high viscosity. In this study, mixing condition after and before adding cement into the liquid waste was estimated. The mixing condition was set with consideration to keep anion concentration low in the ground water and of mixing easily enough in practical operation. Long term leaching behavior of the simulated solidified waste was also analyzed by PHREEQC. And the concentration of the constitution affected to the disposal facility was estimated be low enough in the ground water. (author)

  15. Evaluation of the Supraglottic and Subglottic Activities Including Acoustic Assessment of the Opera-Chant Singers.

    Science.gov (United States)

    Petekkaya, Emine; Yücel, Ahmet Hilmi; Sürmelioğlu, Özgür

    2017-12-28

    Opera and chant singers learn to effectively use aerodynamic components by breathing exercises during their education. Aerodynamic components, including subglottic air pressure and airflow, deteriorate in voice disorders. This study aimed to evaluate the changes in aerodynamic parameters and supraglottic structures of men and women with different vocal registers who are in an opera and chant education program. Vocal acoustic characteristics, aerodynamic components, and supraglottic structures were evaluated in 40 opera and chant art branch students. The majority of female students were sopranos, and the male students were baritone or tenor vocalists. The acoustic analyses revealed that the mean fundamental frequency was 152.33 Hz in the males and 218.77 Hz in the females. The estimated mean subglottal pressures were similar in females (14.99 cmH 2 O) and in males (14.48 cmH 2 O). Estimated mean airflow rates were also similar in both groups. The supraglottic structure compression analyses revealed partial anterior-posterior compressions in 2 tenors and 2 sopranos, and false vocal fold compression in 2 sopranos. Opera music is sung in high-pitched sounds. Attempts to sing high-pitched notes and frequently using register transitions overstrain the vocal structures. This intense muscular effort eventually traumatizes the vocal structures and causes supraglottic activity. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  16. Macroenvironmental factors including GDP per capita and physical activity in Europe

    NARCIS (Netherlands)

    Cameron, Adrian J.; van Stralen, Maartje M.; Kunst, Anton E.; te Velde, Saskia J.; van Lenthe, Frank J.; Salmon, Jo; Brug, Johannes

    2013-01-01

    Socioeconomic inequalities in physical activity at the individual level are well reported. Whether inequalities in economic development and other macroenvironmental variables between countries are also related to physical activity at the country level is comparatively unstudied. We examined the

  17. Macroenvironmental Factors Including GDP per Capita and Physical Activity in Europe

    NARCIS (Netherlands)

    Cameron, A.J.; van Stralen, M.M.; Kunst, A.E.; te Velde, S.J.; Lenthe, F.J.; Salmon, J.; Brug, J.

    2013-01-01

    Purpose: Socioeconomic inequalities in physical activity at the individual level are well reported. Whether inequalities in economic development and other macroenvironmental variables between countries are also related to physical activity at the country level is comparatively unstudied. Methods: We

  18. Sensor-based activity recognition using extended belief rule-based inference methodology.

    Science.gov (United States)

    Calzada, A; Liu, J; Nugent, C D; Wang, H; Martinez, L

    2014-01-01

    The recently developed extended belief rule-based inference methodology (RIMER+) recognizes the need of modeling different types of information and uncertainty that usually coexist in real environments. A home setting with sensors located in different rooms and on different appliances can be considered as a particularly relevant example of such an environment, which brings a range of challenges for sensor-based activity recognition. Although RIMER+ has been designed as a generic decision model that could be applied in a wide range of situations, this paper discusses how this methodology can be adapted to recognize human activities using binary sensors within smart environments. The evaluation of RIMER+ against other state-of-the-art classifiers in terms of accuracy, efficiency and applicability was found to be significantly relevant, specially in situations of input data incompleteness, and it demonstrates the potential of this methodology and underpins the basis to develop further research on the topic.

  19. Development of a versatile readout and test system and characterization of a capacitively coupled active pixel sensor

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, Jens; Gonella, Laura; Hemperek, Tomasz; Hirono, Toko; Huegging, Fabian; Krueger, Hans; Wermes, Norbert [Institute of Physics, University of Bonn, Bonn (Germany); Peric, Ivan [Karlsruher Institut fuer Technologie, Karlsruhe (Germany); Collaboration: ATLAS-Collaboration

    2015-07-01

    With the availability of high voltage and high resistivity CMOS processes, active pixel sensors are becoming increasingly interesting for radiation detection in high energy physics experiments. Although the pixel signal-to-noise ratio and the sensor radiation tolerance were improved, active pixel sensors cannot yet compete with state-of-the-art hybrid pixel detector in a high radiation environment. Hence, active pixel sensors are possible candidates for the outer tracking detector in HEP experiments where production cost plays a role. The investigation of numerous prototyping steps and different technologies is still ongoing and requires a versatile test and readout system, which will be presented in this talk. A capacitively coupled active pixel sensor fabricated in AMS 180 nm high voltage CMOS process is investigated. The sensor is designed to be glued to existing front-end pixel readout chips. Results from the characterization are presented in this talk.

  20. DNA-Based Sensor for Real-Time Measurement of the Enzymatic Activity of Human Topoisomerase I

    DEFF Research Database (Denmark)

    Marcussen, Lærke Bay; Jepsen, Morten Leth; Kristoffersen, Emil Laust

    2013-01-01

    Sensors capable of quantitative real-time measurements may present the easiest and most accurate way to study enzyme activities. Here we present a novel DNA-based sensor for specific and quantitative real-time measurement of the enzymatic activity of the essential human enzyme, topoisomerase I....... The basic design of the sensor relies on two DNA strands that hybridize to form a hairpin structure with a fluorophore-quencher pair. The quencher moiety is released from the sensor upon reaction with human topoisomerase I thus enabling real-time optical measurement of enzymatic activity. The sensor....... The cytotoxic effect of camptothecins correlates directly with the intracellular topoisomerase I activity. We therefore envision that the presented sensor may find use for the prediction of cellular drug response. Moreover, inhibition of topoisomerase I by camptothecin is readily detectable using the presented...

  1. An activity recognition model using inertial sensor nodes in a wireless sensor network for frozen shoulder rehabilitation exercises.

    Science.gov (United States)

    Lin, Hsueh-Chun; Chiang, Shu-Yin; Lee, Kai; Kan, Yao-Chiang

    2015-01-19

    This paper proposes a model for recognizing motions performed during rehabilitation exercises for frozen shoulder conditions. The model consists of wearable wireless sensor network (WSN) inertial sensor nodes, which were developed for this study, and enables the ubiquitous measurement of bodily motions. The model employs the back propagation neural network (BPNN) algorithm to compute motion data that are formed in the WSN packets; herein, six types of rehabilitation exercises were recognized. The packets sent by each node are converted into six components of acceleration and angular velocity according to three axes. Motor features such as basic acceleration, angular velocity, and derivative tilt angle were input into the training procedure of the BPNN algorithm. In measurements of thirteen volunteers, the accelerations and included angles of nodes were adopted from possible features to demonstrate the procedure. Five exercises involving simple swinging and stretching movements were recognized with an accuracy of 85%-95%; however, the accuracy with which exercises entailing spiral rotations were recognized approximately 60%. Thus, a characteristic space and enveloped spectrum improving derivative features were suggested to enable identifying customized parameters. Finally, a real-time monitoring interface was developed for practical implementation. The proposed model can be applied in ubiquitous healthcare self-management to recognize rehabilitation exercises.

  2. An Activity Recognition Model Using Inertial Sensor Nodes in a Wireless Sensor Network for Frozen Shoulder Rehabilitation Exercises

    Directory of Open Access Journals (Sweden)

    Hsueh-Chun Lin

    2015-01-01

    Full Text Available This paper proposes a model for recognizing motions performed during rehabilitation exercises for frozen shoulder conditions. The model consists of wearable wireless sensor network (WSN inertial sensor nodes, which were developed for this study, and enables the ubiquitous measurement of bodily motions. The model employs the back propagation neural network (BPNN algorithm to compute motion data that are formed in the WSN packets; herein, six types of rehabilitation exercises were recognized. The packets sent by each node are converted into six components of acceleration and angular velocity according to three axes. Motor features such as basic acceleration, angular velocity, and derivative tilt angle were input into the training procedure of the BPNN algorithm. In measurements of thirteen volunteers, the accelerations and included angles of nodes were adopted from possible features to demonstrate the procedure. Five exercises involving simple swinging and stretching movements were recognized with an accuracy of 85%–95%; however, the accuracy with which exercises entailing spiral rotations were recognized approximately 60%. Thus, a characteristic space and enveloped spectrum improving derivative features were suggested to enable identifying customized parameters. Finally, a real-time monitoring interface was developed for practical implementation. The proposed model can be applied in ubiquitous healthcare self-management to recognize rehabilitation exercises.

  3. Design, synthesis and structure of new potential electrochemically active boronic acid-based glucose sensors

    DEFF Research Database (Denmark)

    Norrild, Jens Chr.; Søtofte, Inger

    2002-01-01

    In the course of our investigations on new boronic acid based carbohydrate sensors three new boronic acids 3, 7 and 11 containing a ferrocene moiety were synthesised. Their design includes an intramolecular B-N bonding motif in order to facilitate binding at physiological pH. We report the synthe......In the course of our investigations on new boronic acid based carbohydrate sensors three new boronic acids 3, 7 and 11 containing a ferrocene moiety were synthesised. Their design includes an intramolecular B-N bonding motif in order to facilitate binding at physiological pH. We report...

  4. Virtual sensors for active noise control in acoustic-structural coupled enclosures using structural sensing: part II--Optimization of structural sensor placement.

    Science.gov (United States)

    Halim, Dunant; Cheng, Li; Su, Zhongqing

    2011-04-01

    The work proposed an optimization approach for structural sensor placement to improve the performance of vibro-acoustic virtual sensor for active noise control applications. The vibro-acoustic virtual sensor was designed to estimate the interior sound pressure of an acoustic-structural coupled enclosure using structural sensors. A spectral-spatial performance metric was proposed, which was used to quantify the averaged structural sensor output energy of a vibro-acoustic system excited by a spatially varying point source. It was shown that (i) the overall virtual sensing error energy was contributed additively by the modal virtual sensing error and the measurement noise energy; (ii) each of the modal virtual sensing error system was contributed by both the modal observability levels for the structural sensing and the target acoustic virtual sensing; and further (iii) the strength of each modal observability level was influenced by the modal coupling and resonance frequencies of the associated uncoupled structural/cavity modes. An optimal design of structural sensor placement was proposed to achieve sufficiently high modal observability levels for certain important panel- and cavity-controlled modes. Numerical analysis on a panel-cavity system demonstrated the importance of structural sensor placement on virtual sensing and active noise control performance, particularly for cavity-controlled modes.

  5. 16 CFR 1211.13 - Inherent force activated secondary door sensors.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Inherent force activated secondary door sensors. 1211.13 Section 1211.13 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT... across the door so that the axis is perpendicular to the plane of the door. See Figure 6 of this part...

  6. Derivation of a regional active-optical reflectance sensor corn algorithm

    Science.gov (United States)

    Active-optical reflectance sensor (AORS) algorithms developed for in-season corn (Zea mays L.) N management have traditionally been derived using sub-regional scale information. However, studies have shown these previously developed AORS algorithms are not consistently accurate when used on a region...

  7. [High-Performance Active Pixel X-Ray Sensors for X-Ray Astronomy

    Science.gov (United States)

    Bautz, Mark; Suntharalingam, Vyshnavi

    2005-01-01

    The subject grants support development of High-Performance Active Pixel Sensors for X-ray Astronomy at the Massachusetts Institute of Technology (MIT) Center for Space Research and at MIT's Lincoln Laboratory. This memo reports our progress in the second year of the project, from April, 2004 through the present.

  8. Hot pixel generation in active pixel sensors: dosimetric and micro-dosimetric response

    Science.gov (United States)

    Scheick, Leif; Novak, Frank

    2003-01-01

    The dosimetric response of an active pixel sensor is analyzed. heavy ions are seen to damage the pixel in much the same way as gamma radiation. The probability of a hot pixel is seen to exhibit behavior that is not typical with other microdose effects.

  9. Dirichlet Process Gaussian Mixture Model for Activity Discovery in Smart Homes with Ambient Sensors

    NARCIS (Netherlands)

    Nguyen, Thuong; Le Viet Duc, Duc Viet; Zhang, Quing; Karunanithi, Mohan

    2017-01-01

    Most of the existing approaches to activity recognition in smart homes rely on supervised learning with well annotated sensor data. However obtaining such labeled data is not only challenging but sometimes also an unobtainable task, especially for senior citizens who may suffer various mental health

  10. CMOS Active Pixel Sensors for Low Power, Highly Miniaturized Imaging Systems

    Science.gov (United States)

    Fossum, Eric R.

    1996-01-01

    The complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology has been developed over the past three years by NASA at the Jet Propulsion Laboratory, and has reached a level of performance comparable to CCDs with greatly increased functionality but at a very reduced power level.

  11. New generation of monolithic active pixel sensors for charged particle detection

    International Nuclear Information System (INIS)

    Deptuch, G.

    2002-09-01

    Vertex detectors are of great importance in particle physics experiments, as the knowledge of the event flavour is becoming an issue for the physics programme at Future Linear Colliders. Monolithic Active Pixel Sensors (MAPS) based on a novel detector structure have been proposed. Their fabrication is compatible with a standard CMOS process. The sensor is inseparable from the readout electronics, since both of them are integrated on the same, low-resistivity silicon wafer. The basic pixel configuration comprises only three MOS transistors and a diode collecting the charge through thermal diffusion. The charge is generated in the thin non-depleted epitaxial layer underneath the readout electronics. This approach provides, at low cost, a high resolution and thin device with the whole area sensitive to radiation. Device simulations using the ISE-TCAD package have been carried out to study the charge collection mechanism. In order to demonstrate the viability of the technique, four prototype chips have been fabricated using different submicrometer CMOS processes. The pixel gain has been calibrated using a 55 Fe source and the Poisson sequence method. The prototypes have been exposed to high-energy particle beams at CERN. The tests proved excellent detection performances expressed in a single-track spatial resolution of 1.5 μm and detection efficiency close to 100%, resulting from a SNR ratio of more than 30. Irradiation tests showed immunity of MAPS to a level of a few times 10 12 n/cm 2 and a few hundred kRad of ionising radiation. The ideas for future work, including on-pixel signal amplification, double sampling operation and current mode pixel design are present as well. (author)

  12. Approach for the Development of a Framework for the Identification of Activities of Daily Living Using Sensors in Mobile Devices

    Science.gov (United States)

    Pombo, Nuno

    2018-01-01

    Sensors available on mobile devices allow the automatic identification of Activities of Daily Living (ADL). This paper describes an approach for the creation of a framework for the identification of ADL, taking into account several concepts, including data acquisition, data processing, data fusion, and pattern recognition. These concepts can be mapped onto different modules of the framework. The proposed framework should perform the identification of ADL without Internet connection, performing these tasks locally on the mobile device, taking in account the hardware and software limitations of these devices. The main purpose of this paper is to present a new approach for the creation of a framework for the recognition of ADL, analyzing the allowed sensors available in the mobile devices, and the existing methods available in the literature. PMID:29466316

  13. Approach for the Development of a Framework for the Identification of Activities of Daily Living Using Sensors in Mobile Devices.

    Science.gov (United States)

    Pires, Ivan Miguel; Garcia, Nuno M; Pombo, Nuno; Flórez-Revuelta, Francisco; Spinsante, Susanna

    2018-02-21

    Sensors available on mobile devices allow the automatic identification of Activities of Daily Living (ADL). This paper describes an approach for the creation of a framework for the identification of ADL, taking into account several concepts, including data acquisition, data processing, data fusion, and pattern recognition. These concepts can be mapped onto different modules of the framework. The proposed framework should perform the identification of ADL without Internet connection, performing these tasks locally on the mobile device, taking in account the hardware and software limitations of these devices. The main purpose of this paper is to present a new approach for the creation of a framework for the recognition of ADL, analyzing the allowed sensors available in the mobile devices, and the existing methods available in the literature.

  14. Center of mass detection via an active pixel sensor

    Science.gov (United States)

    Yadid-Pecht, Orly (Inventor); Minch, Brad (Inventor); Pain, Bedabrara (Inventor); Fossum, Eric (Inventor)

    2006-01-01

    An imaging system for identifying the location of the center of mass (COM) in an image. In one aspect, an imaging system includes a plurality of photosensitive elements arranged in a matrix. A center of mass circuit coupled to the photosensitive elements includes a resistive network and a normalization circuit including at least one bipolar transistor. The center of mass circuit identifies a center of mass location in the matrix and includes: a row circuit, where the row circuit identifies a center of mass row value in each row of the matrix and identifies a row intensity for each row; a horizontal circuit, where the horizontal circuit identifies a center of mass horizontal value; and a vertical circuit, where the vertical circuit identifies a center of mass vertical value. The horizontal and vertical center of mass values indicate the coordinates of the center of mass location for the image.

  15. Does limited virucidal activity of biocides include duck hepatitis B virucidal action?

    Directory of Open Access Journals (Sweden)

    Sauerbrei Andreas

    2012-10-01

    Full Text Available Abstract Background There is agreement that the infectivity assay with the duck hepatitis B virus (DHBV is a suitable surrogate test to validate disinfectants for hepatitis B virucidal activity. However, since this test is not widely used, information is necessary whether disinfectants with limited virucidal activity also inactivate DHBV. In general, disinfectants with limited virucidal activity are used for skin and sensitive surfaces while agents with full activity are more aggressive. The present study compares the activity of five different biocides against DHBV and the classical test virus for limited virucidal activity, the vaccinia virus strain Lister Elstree (VACV or the modified vaccinia Ankara strain (MVA. Methods Virucidal assay was performed as suspension test according to the German DVV/RKI guideline. Duck hepatitis B virus obtained from congenitally infected Peking ducks was propagated in primary duck embryonic hepatocytes and was detected by indirect immunofluorescent antigen staining. Results The DHBV was inactivated by the use of 40% ethanol within 1-min and 30% isopropanol within 2-min exposure. In comparison, 40% ethanol within 2-min and 40% isopropanol within 1-min exposure were effective against VACV/MVA. These alcohols only have limited virucidal activity, while the following agents have full activity. 0.01% peracetic acid inactivated DHBV within 2 min and a concentration of 0.005% had virucidal efficacy against VACV/MVA within 1 min. After 2-min exposure, 0.05% glutardialdehyde showed a comparable activity against DHBV and VACV/MVA. This is also the case for 0.7% formaldehyde after a contact time of 30 min. Conclusions Duck hepatitis B virus is at least as sensitive to limited virucidal activity as VACV/MVA. Peracetic acid is less effective against DHBV, while the alcohols are less effective against VACV/MVA. It can be expected that in absence of more direct tests the results may be extrapolated to HBV.

  16. Sensor scheme design for active structural acoustic control

    NARCIS (Netherlands)

    Berkhoff, Arthur P.

    Efficient sensing schemes for the active reduction of sound radiation from plates are presented based on error signals derived from spatially weighted plate velocity or near-field pressure. The schemes result in near-optimal reductions as compared to weighting procedures derived from eigenvector or

  17. A monolithic active pixel sensor for ionizing radiation using a 180 nm HV-SOI process

    Energy Technology Data Exchange (ETDEWEB)

    Hemperek, Tomasz; Kishishita, Tetsuichi; Krueger, Hans; Wermes, Norbert [Institute of Physics, University of Bonn, Bonn (Germany)

    2016-07-01

    An improved SOI-MAPS (Silicon On Insulator Monolithic Active Pixel Sensor) for ionizing radiation based on thick-180 nm High Voltage SOI technology (HV-SOI) has been developed. Similar to existing Fully Depleted SOI-based (FD-SOI) MAPS, a buried silicon oxide inter-dielectric (BOX) layer is used to separate the CMOS electronics from the handle wafer which is used as a depleted charge collection layer. Standard FD-SOI MAPS suffer from radiation damage such as transistor threshold voltage shifts due to trapped charge in the buried oxide layer and charged interface states created at the silicon oxide boundaries (back gate effect). The X-FAB 180 nm HV-SOI technology offers an additional isolation using a deep non-depleted implant between the BOX layer and the active circuitry which mitigates this problem. Therefore we see in this technology a high potential to implement radiation-tolerant MAPS with fast charge collection. The design and measurement results from first prototypes are presented including radiation tolerance to total ionizing dose and charge collection properties of neutron irradiated samples.

  18. A Monolithic Active Pixel Sensor for ionizing radiation using a 180 nm HV-SOI process

    Energy Technology Data Exchange (ETDEWEB)

    Hemperek, Tomasz, E-mail: hemperek@uni-bonn.de; Kishishita, Tetsuichi; Krüger, Hans; Wermes, Norbert

    2015-10-01

    An improved SOI-MAPS (Silicon On Insulator Monolithic Active Pixel Sensor) for ionizing radiation based on thick-film High Voltage SOI technology (HV-SOI) has been developed. Similar to existing Fully Depleted SOI-based (FD-SOI) MAPS, a buried silicon oxide inter-dielectric (BOX) layer is used to separate the CMOS electronics from the handle wafer which is used as a depleted charge collection layer. FD-SOI MAPS suffers from radiation damage such as transistor threshold voltage shifts due to charge traps in the oxide layers and charge states created at the silicon oxide boundaries (back gate effect). The X-FAB 180-nm HV-SOI technology offers an additional isolation by deep non-depleted implant between the BOX layer and the active circuitry which mitigates this problem. Therefore we see in this technology a high potential to implement radiation-tolerant MAPS with fast charge collection property. The design and measurement results from a first prototype are presented including charge collection in neutron irradiated samples.

  19. Advanced Gas Sensors Using SERS-Activated Waveguides

    Science.gov (United States)

    Lascola, Robert; McWhorter, Scott; Murph, Simona Hunyadi

    2010-08-01

    non-specific interactions between the surface coating and additional nanoparticles suspended in solution to which the analyte had been coupled. Clearly, for a gas sensor, such a scheme is not feasible, and in any event the reliance on the random configuration of the nanoparticles and the analyte is not expected to lead to efficient enhancement. Here, we report the creation of capillary coatings of self-assembled, aggregated high aspect ratio metallic nanoparticles (e.g. rod, wires) with a solution-phase technique. Self-assembly offers the possibility for a high density of SERS hot spots, which are often observed at the junction of adjacent particles. Shaped nanoparticles also enhance self-assembled deposition, and allow further control of the optical properties of the coating through manipulation of the morphology. SERS enhancements for gases are reported relative to mirrored capillaries and free-space measurements.

  20. Active pixel sensor with intra-pixel charge transfer

    Science.gov (United States)

    Fossum, Eric R. (Inventor); Mendis, Sunetra (Inventor); Kemeny, Sabrina E. (Inventor)

    2004-01-01

    An imaging device formed as a monolithic complementary metal oxide semiconductor integrated circuit in an industry standard complementary metal oxide semiconductor process, the integrated circuit including a focal plane array of pixel cells, each one of the cells including a photogate overlying the substrate for accumulating photo-generated charge in an underlying portion of the substrate, a readout circuit including at least an output field effect transistor formed in the substrate, and a charge coupled device section formed on the substrate adjacent the photogate having a sensing node connected to the output transistor and at least one charge coupled device stage for transferring charge from the underlying portion of the substrate to the sensing node.

  1. Continuous Water Vapor Profiles from Operational Ground-Based Active and Passive Remote Sensors

    Science.gov (United States)

    Turner, D. D.; Feltz, W. F.; Ferrare, R. A.

    2000-01-01

    The Atmospheric Radiation Measurement program's Southern Great Plains Cloud and Radiation Testbed site central facility near Lamont, Oklahoma, offers unique operational water vapor profiling capabilities, including active and passive remote sensors as well as traditional in situ radiosonde measurements. Remote sensing technologies include an automated Raman lidar and an automated Atmospheric Emitted Radiance Interferometer (AERI), which are able to retrieve water vapor profiles operationally through the lower troposphere throughout the diurnal cycle. Comparisons of these two water vapor remote sensing methods to each other and to radiosondes over an 8-month period are presented and discussed, highlighting the accuracy and limitations of each method. Additionally, the AERI is able to retrieve profiles of temperature while the Raman lidar is able to retrieve aerosol extinction profiles operationally. These data, coupled with hourly wind profiles from a 915-MHz wind profiler, provide complete specification of the state of the atmosphere in noncloudy skies. Several case studies illustrate the utility of these high temporal resolution measurements in the characterization of mesoscale features within a 3-day time period in which passage of a dryline, warm air advection, and cold front occurred.

  2. The promise of mHealth: daily activity monitoring and outcome assessments by wearable sensors.

    Science.gov (United States)

    Dobkin, Bruce H; Dorsch, Andrew

    2011-01-01

    Mobile health tools that enable clinicians and researchers to monitor the type, quantity, and quality of everyday activities of patients and trial participants have long been needed to improve daily care, design more clinically meaningful randomized trials of interventions, and establish cost-effective, evidence-based practices. Inexpensive, unobtrusive wireless sensors, including accelerometers, gyroscopes, and pressure-sensitive textiles, combined with Internet-based communications and machine-learning algorithms trained to recognize upper- and lower-extremity movements, have begun to fulfill this need. Continuous data from ankle triaxial accelerometers, for example, can be transmitted from the home and community via WiFi or a smartphone to a remote data analysis server. Reports can include the walking speed and duration of every bout of ambulation, spatiotemporal symmetries between the legs, and the type, duration, and energy used during exercise. For daily care, this readily accessible flow of real-world information allows clinicians to monitor the amount and quality of exercise for risk factor management and compliance in the practice of skills. Feedback may motivate better self-management as well as serve home-based rehabilitation efforts. Monitoring patients with chronic diseases and after hospitalization or the start of new medications for a decline in daily activity may help detect medical complications before rehospitalization becomes necessary. For clinical trials, repeated laboratory-quality assessments of key activities in the community, rather than by clinic testing, self-report, and ordinal scales, may reduce the cost and burden of travel, improve recruitment and retention, and capture more reliable, valid, and responsive ratio-scaled outcome measures that are not mere surrogates for changes in daily impairment, disability, and functioning.

  3. Unobtrusive measurement of indoor energy expenditure using an infrared sensor-based activity monitoring system.

    Science.gov (United States)

    Hwang, Bosun; Han, Jonghee; Choi, Jong Min; Park, Kwang Suk

    2008-11-01

    The purpose of this study was to develop an unobtrusive energy expenditure (EE) measurement system using an infrared (IR) sensor-based activity monitoring system to measure indoor activities and to estimate individual quantitative EE. IR-sensor activation counts were measured with a Bluetooth-based monitoring system and the standard EE was calculated using an established regression equation. Ten male subjects participated in the experiment and three different EE measurement systems (gas analyzer, accelerometer, IR sensor) were used simultaneously in order to determine the regression equation and evaluate the performance. As a standard measurement, oxygen consumption was simultaneously measured by a portable metabolic system (Metamax 3X, Cortex, Germany). A single room experiment was performed to develop a regression model of the standard EE measurement from the proposed IR sensor-based measurement system. In addition, correlation and regression analyses were done to compare the performance of the IR system with that of the Actigraph system. We determined that our proposed IR-based EE measurement system shows a similar correlation to the Actigraph system with the standard measurement system.

  4. CMOS active pixel sensor type imaging system on a chip

    Science.gov (United States)

    Fossum, Eric R. (Inventor); Nixon, Robert (Inventor)

    2011-01-01

    A single chip camera which includes an .[.intergrated.]. .Iadd.integrated .Iaddend.image acquisition portion and control portion and which has double sampling/noise reduction capabilities thereon. Part of the .[.intergrated.]. .Iadd.integrated .Iaddend.structure reduces the noise that is picked up during imaging.

  5. Modular Bayesian Networks with Low-Power Wearable Sensors for Recognizing Eating Activities

    Directory of Open Access Journals (Sweden)

    Kee-Hoon Kim

    2017-12-01

    Full Text Available Recently, recognizing a user’s daily activity using a smartphone and wearable sensors has become a popular issue. However, in contrast with the ideal definition of an experiment, there could be numerous complex activities in real life with respect to its various background and contexts: time, space, age, culture, and so on. Recognizing these complex activities with limited low-power sensors, considering the power and memory constraints of the wearable environment and the user’s obtrusiveness at once is not an easy problem, although it is very crucial for the activity recognizer to be practically useful. In this paper, we recognize activity of eating, which is one of the most typical examples of a complex activity, using only daily low-power mobile and wearable sensors. To organize the related contexts systemically, we have constructed the context model based on activity theory and the “Five W’s”, and propose a Bayesian network with 88 nodes to predict uncertain contexts probabilistically. The structure of the proposed Bayesian network is designed by a modular and tree-structured approach to reduce the time complexity and increase the scalability. To evaluate the proposed method, we collected the data with 10 different activities from 25 volunteers of various ages, occupations, and jobs, and have obtained 79.71% accuracy, which outperforms other conventional classifiers by 7.54–14.4%. Analyses of the results showed that our probabilistic approach could also give approximate results even when one of contexts or sensor values has a very heterogeneous pattern or is missing.

  6. Modular Bayesian Networks with Low-Power Wearable Sensors for Recognizing Eating Activities

    Science.gov (United States)

    Kim, Kee-Hoon

    2017-01-01

    Recently, recognizing a user’s daily activity using a smartphone and wearable sensors has become a popular issue. However, in contrast with the ideal definition of an experiment, there could be numerous complex activities in real life with respect to its various background and contexts: time, space, age, culture, and so on. Recognizing these complex activities with limited low-power sensors, considering the power and memory constraints of the wearable environment and the user’s obtrusiveness at once is not an easy problem, although it is very crucial for the activity recognizer to be practically useful. In this paper, we recognize activity of eating, which is one of the most typical examples of a complex activity, using only daily low-power mobile and wearable sensors. To organize the related contexts systemically, we have constructed the context model based on activity theory and the “Five W’s”, and propose a Bayesian network with 88 nodes to predict uncertain contexts probabilistically. The structure of the proposed Bayesian network is designed by a modular and tree-structured approach to reduce the time complexity and increase the scalability. To evaluate the proposed method, we collected the data with 10 different activities from 25 volunteers of various ages, occupations, and jobs, and have obtained 79.71% accuracy, which outperforms other conventional classifiers by 7.54–14.4%. Analyses of the results showed that our probabilistic approach could also give approximate results even when one of contexts or sensor values has a very heterogeneous pattern or is missing. PMID:29232937

  7. A Sensor Web and Web Service-Based Approach for Active Hydrological Disaster Monitoring

    Directory of Open Access Journals (Sweden)

    Xi Zhai

    2016-09-01

    Full Text Available Rapid advancements in Earth-observing sensor systems have led to the generation of large amounts of remote sensing data that can be used for the dynamic monitoring and analysis of hydrological disasters. The management and analysis of these data could take advantage of distributed information infrastructure technologies such as Web service and Sensor Web technologies, which have shown great potential in facilitating the use of observed big data in an interoperable, flexible and on-demand way. However, it remains a challenge to achieve timely response to hydrological disaster events and to automate the geoprocessing of hydrological disaster observations. This article proposes a Sensor Web and Web service-based approach to support active hydrological disaster monitoring. This approach integrates an event-driven mechanism, Web services, and a Sensor Web and coordinates them using workflow technologies to facilitate the Web-based sharing and processing of hydrological hazard information. The design and implementation of hydrological Web services for conducting various hydrological analysis tasks on the Web using dynamically updating sensor observation data are presented. An application example is provided to demonstrate the benefits of the proposed approach over the traditional approach. The results confirm the effectiveness and practicality of the proposed approach in cases of hydrological disaster.

  8. Active Hearing Mechanisms Inspire Adaptive Amplification in an Acoustic Sensor System.

    Science.gov (United States)

    Guerreiro, Jose; Reid, Andrew; Jackson, Joseph C; Windmill, James F C

    2018-06-01

    Over many millions of years of evolution, nature has developed some of the most adaptable sensors and sensory systems possible, capable of sensing, conditioning and processing signals in a very power- and size-effective manner. By looking into biological sensors and systems as a source of inspiration, this paper presents the study of a bioinspired concept of signal processing at the sensor level. By exploiting a feedback control mechanism between a front-end acoustic receiver and back-end neuronal based computation, a nonlinear amplification with hysteretic behavior is created. Moreover, the transient response of the front-end acoustic receiver can also be controlled and enhanced. A theoretical model is proposed and the concept is prototyped experimentally through an embedded system setup that can provide dynamic adaptations of a sensory system comprising a MEMS microphone placed in a closed-loop feedback system. It faithfully mimics the mosquito's active hearing response as a function of the input sound intensity. This is an adaptive acoustic sensor system concept that can be exploited by sensor and system designers within acoustics and ultrasonic engineering fields.

  9. Diaper-Embedded Urinary Tract Infection Monitoring Sensor Module Powered by Urine-Activated Batteries.

    Science.gov (United States)

    Seo, Weeseong; Yu, Wuyang; Tan, Tianlin; Ziaie, Babak; Jung, Byunghoo

    2017-06-01

    Urinary tract infection (UTI) is one of the most common infections in humans. UTI is easily treatable using antibiotics if identified in early stage. However, without early identification and treatment, UTI can be a major source of serious complications in geriatric patients, in particular, those suffering from neurodegenerative diseases. Also, for infants who have difficulty in describing their symptoms, UTI may lead to serious development of the disease making early identification of UTI crucial. In this paper, we present a diaper-embedded, wireless, self-powered, and autonomous UTI monitoring sensor module that allows an early detection of UTI with minimal effort. The sensor module consists of a paper-based colorimetric nitrite sensor, urine-activated batteries, a boost dc-dc converter, a low-power sensor interface utilizing pulse width modulation, and a Bluetooth low energy module for wireless transmission. Experimental results show a better detection of nitrite, a surrogate of UTI, than that of conventional dipstick testing. The proposed sensor module achieves a sensitivity of 1.35 ms/(mg/L) and a detection limit of 4 mg/L for nitrite.

  10. Rail Sensor Testbed Program: Active Agents in Containers for Transport Chain Security

    Science.gov (United States)

    2011-01-01

    applied to a variety of regimes, including virtual communities [14], email [15] and ecommerce [16] and [17], and sensor networks [18]. These approaches...effective anti- spam tool. 2004(http://www.arxiv.org/abs/cond-mat/0402143). 16. Melnik, M., Alm, J., Does a seller’s eCommerce reputation matter

  11. Light Controls Cytokinin Signaling via Transcriptional Regulation of Constitutively Active Sensor Histidine Kinase CKI1.

    Science.gov (United States)

    Dobisova, Tereza; Hrdinova, Vendula; Cuesta, Candela; Michlickova, Sarka; Urbankova, Ivana; Hejatkova, Romana; Zadnikova, Petra; Pernisova, Marketa; Benkova, Eva; Hejatko, Jan

    2017-05-01

    In plants, the multistep phosphorelay (MSP) pathway mediates a range of regulatory processes, including those activated by cytokinins. The cross talk between cytokinin response and light has been known for a long time. However, the molecular mechanism underlying the interaction between light and cytokinin signaling remains elusive. In the screen for upstream regulators we identified a LONG PALE HYPOCOTYL ( LPH ) gene whose activity is indispensable for spatiotemporally correct expression of CYTOKININ INDEPENDENT1 ( CKI1 ), encoding the constitutively active sensor His kinase that activates MSP signaling. lph is a new allele of HEME OXYGENASE1 ( HY1 ) that encodes the key protein in the biosynthesis of phytochromobilin, a cofactor of photoconvertible phytochromes. Our analysis confirmed the light-dependent regulation of the CKI1 expression pattern. We show that CKI1 expression is under the control of phytochrome A (phyA), functioning as a dual (both positive and negative) regulator of CKI1 expression, presumably via the phyA-regulated transcription factors (TF) PHYTOCHROME INTERACTING FACTOR3 and CIRCADIAN CLOCK ASSOCIATED1. Changes in CKI1 expression observed in lph / hy1 - 7 and phy mutants correlate with misregulation of MSP signaling, changed cytokinin sensitivity, and developmental aberrations that were previously shown to be associated with cytokinin and/or CKI1 action. Besides that, we demonstrate a novel role of phyA-dependent CKI1 expression in the hypocotyl elongation and hook development during skotomorphogenesis. Based on these results, we propose that the light-dependent regulation of CKI1 provides a plausible mechanistic link underlying the well-known interaction between light- and cytokinin-controlled plant development. © 2017 American Society of Plant Biologists. All Rights Reserved.

  12. Intracellular activity of clinical concentrations of phenothiazines including thioridiazine against phagocytosed Staphylococcus aureus.

    Science.gov (United States)

    Ordway, Diane; Viveiros, Miguel; Leandro, Clara; Arroz, Maria Jorge; Amaral, Leonard

    2002-07-01

    The effect of thioridazine (TZ) was studied on the killing activity of human peripheral blood monocyte derived macrophages (HPBMDM) and of human macrophage cell line THP-1 at extracellular concentrations below those achievable clinically. These macrophages have nominal killing activity against bacteria and therefore, would not influence any activity that the compounds may have against intracellular localised Staphylococcus aureus. The results indicated that whereas TZ has an in vitro minimum inhibitory concentration (MIC) against the strains of S. aureus of 18, 0.1 mg/l of TZ in the medium completely inhibits the growth of S. aureus that has been phagocytosed by macrophages. The latter concentration was non-toxic to macrophages, did not cause cellular expression of activation marker CD69 nor induction of CD3+ T cell production of IFN-gamma, but blocked cellular proliferation and down-regulated the production of T cell-derived cytokines (IFN-gamma, IL-5). These results suggest that TZ induces intracellular bactericidal activities independent of the capacity to generate Type 1 responses against S. aureus.

  13. First tests of CHERWELL, a Monolithic Active Pixel Sensor: A CMOS Image Sensor (CIS) using 180 nm technology

    Energy Technology Data Exchange (ETDEWEB)

    Mylroie-Smith, James, E-mail: j.mylroie-smith@qmul.ac.uk [Queen Mary, University of London (United Kingdom); Kolya, Scott; Velthuis, Jaap [University of Bristol (United Kingdom); Bevan, Adrian; Inguglia, Gianluca [Queen Mary, University of London (United Kingdom); Headspith, Jon; Lazarus, Ian; Lemon, Roy [Daresbury Laboratory, STFC (United Kingdom); Crooks, Jamie; Turchetta, Renato; Wilson, Fergus [Rutherford Appleton Laboratory, STFC (United Kingdom)

    2013-12-11

    The Cherwell is a 4T CMOS sensor in 180 nm technology developed for the detection of charged particles. Here, the different test structures on the sensor will be described and first results from tests on the reference pixel variant are shown. The sensors were shown to have a noise of 12 e{sup −} and a signal to noise up to 150 in {sup 55}Fe.

  14. Parameterization of cloud droplet formation for global and regional models: including adsorption activation from insoluble CCN

    Directory of Open Access Journals (Sweden)

    P. Kumar

    2009-04-01

    Full Text Available Dust and black carbon aerosol have long been known to exert potentially important and diverse impacts on cloud droplet formation. Most studies to date focus on the soluble fraction of these particles, and overlook interactions of the insoluble fraction with water vapor (even if known to be hydrophilic. To address this gap, we developed a new parameterization that considers cloud droplet formation within an ascending air parcel containing insoluble (but wettable particles externally mixed with aerosol containing an appreciable soluble fraction. Activation of particles with a soluble fraction is described through well-established Köhler theory, while the activation of hydrophilic insoluble particles is treated by "adsorption-activation" theory. In the latter, water vapor is adsorbed onto insoluble particles, the activity of which is described by a multilayer Frenkel-Halsey-Hill (FHH adsorption isotherm modified to account for particle curvature. We further develop FHH activation theory to i find combinations of the adsorption parameters AFHH, BFHH which yield atmospherically-relevant behavior, and, ii express activation properties (critical supersaturation that follow a simple power law with respect to dry particle diameter.

    The new parameterization is tested by comparing the parameterized cloud droplet number concentration against predictions with a detailed numerical cloud model, considering a wide range of particle populations, cloud updraft conditions, water vapor condensation coefficient and FHH adsorption isotherm characteristics. The agreement between parameterization and parcel model is excellent, with an average error of 10% and R2~0.98. A preliminary sensitivity study suggests that the sublinear response of droplet number to Köhler particle concentration is not as strong for FHH particles.

  15. Using assistive technology adaptations to include students with learning disabilities in cooperative learning activities.

    Science.gov (United States)

    Bryant, D P; Bryant, B R

    1998-01-01

    Cooperative learning (CL) is a common instructional arrangement that is used by classroom teachers to foster academic achievement and social acceptance of students with and without learning disabilities. Cooperative learning is appealing to classroom teachers because it can provide an opportunity for more instruction and feedback by peers than can be provided by teachers to individual students who require extra assistance. Recent studies suggest that students with LD may need adaptations during cooperative learning activities. The use of assistive technology adaptations may be necessary to help some students with LD compensate for their specific learning difficulties so that they can engage more readily in cooperative learning activities. A process for integrating technology adaptations into cooperative learning activities is discussed in terms of three components: selecting adaptations, monitoring the use of the adaptations during cooperative learning activities, and evaluating the adaptations' effectiveness. The article concludes with comments regarding barriers to and support systems for technology integration, technology and effective instructional practices, and the need to consider technology adaptations for students who have learning disabilities.

  16. Observing a fictitious stressful event: haematological changes, including circulating leukocyte activation.

    Science.gov (United States)

    Mian, Rubina; Shelton-Rayner, Graham; Harkin, Brendan; Williams, Paul

    2003-03-01

    The aim of this study was to assess the effect of watching a psychological stressful event on the activation of leukocytes in healthy human volunteers. Blood samples were obtained from 32 healthy male and female subjects aged between 20 and 26 years before, during and after either watching an 83-minute horror film that none of the subjects had previously seen (The Texas Chainsaw Massacre, 1974) or by sitting quietly in a room (control group). Total differential cell counts, leukocyte activation as measured by the nitroblue tetrazolium (NBT) test, heart rate and blood pressure (BP) measurements were taken at defined time points. There were significant increases in peripheral circulating leukocytes, the number of activated circulating leukocytes, haemoglobin (Hb) concentration and haematocrit (Hct) in response to the stressor. These were accompanied by significant increases in heart rate, systolic and diastolic BP (P<0.05 from baseline). This is the first reported study on the effects of observing a psychologically stressful, albeit fictitious event on circulating leukocyte numbers and the state of leukocyte activation as determined by the nitrotetrazolium test.

  17. Mining Emerging Sequential Patterns for Activity Recognition in Body Sensor Networks

    DEFF Research Database (Denmark)

    Gu, Tao; Wang, Liang; Chen, Hanhua

    2010-01-01

    Body Sensor Networks oer many applications in healthcare, well-being and entertainment. One of the emerging applications is recognizing activities of daily living. In this paper, we introduce a novel knowledge pattern named Emerging Sequential Pattern (ESP)|a sequential pattern that discovers...... signicant class dierences|to recognize both simple (i.e., sequential) and complex (i.e., interleaved and concurrent) activities. Based on ESPs, we build our complex activity models directly upon the sequential model to recognize both activity types. We conduct comprehensive empirical studies to evaluate...

  18. Observational Constraints on Cloud Feedbacks: The Role of Active Satellite Sensors

    Science.gov (United States)

    Winker, David; Chepfer, Helene; Noel, Vincent; Cai, Xia

    2017-11-01

    Cloud profiling from active lidar and radar in the A-train satellite constellation has significantly advanced our understanding of clouds and their role in the climate system. Nevertheless, the response of clouds to a warming climate remains one of the largest uncertainties in predicting climate change and for the development of adaptions to change. Both observation of long-term changes and observational constraints on the processes responsible for those changes are necessary. We review recent progress in our understanding of the cloud feedback problem. Capabilities and advantages of active sensors for observing clouds are discussed, along with the importance of active sensors for deriving constraints on cloud feedbacks as an essential component of a global climate observing system.

  19. Training Classifiers with Shadow Features for Sensor-Based Human Activity Recognition.

    Science.gov (United States)

    Fong, Simon; Song, Wei; Cho, Kyungeun; Wong, Raymond; Wong, Kelvin K L

    2017-02-27

    In this paper, a novel training/testing process for building/using a classification model based on human activity recognition (HAR) is proposed. Traditionally, HAR has been accomplished by a classifier that learns the activities of a person by training with skeletal data obtained from a motion sensor, such as Microsoft Kinect. These skeletal data are the spatial coordinates (x, y, z) of different parts of the human body. The numeric information forms time series, temporal records of movement sequences that can be used for training a classifier. In addition to the spatial features that describe current positions in the skeletal data, new features called 'shadow features' are used to improve the supervised learning efficacy of the classifier. Shadow features are inferred from the dynamics of body movements, and thereby modelling the underlying momentum of the performed activities. They provide extra dimensions of information for characterising activities in the classification process, and thereby significantly improve the classification accuracy. Two cases of HAR are tested using a classification model trained with shadow features: one is by using wearable sensor and the other is by a Kinect-based remote sensor. Our experiments can demonstrate the advantages of the new method, which will have an impact on human activity detection research.

  20. Training Classifiers with Shadow Features for Sensor-Based Human Activity Recognition

    Directory of Open Access Journals (Sweden)

    Simon Fong

    2017-02-01

    Full Text Available In this paper, a novel training/testing process for building/using a classification model based on human activity recognition (HAR is proposed. Traditionally, HAR has been accomplished by a classifier that learns the activities of a person by training with skeletal data obtained from a motion sensor, such as Microsoft Kinect. These skeletal data are the spatial coordinates (x, y, z of different parts of the human body. The numeric information forms time series, temporal records of movement sequences that can be used for training a classifier. In addition to the spatial features that describe current positions in the skeletal data, new features called ‘shadow features’ are used to improve the supervised learning efficacy of the classifier. Shadow features are inferred from the dynamics of body movements, and thereby modelling the underlying momentum of the performed activities. They provide extra dimensions of information for characterising activities in the classification process, and thereby significantly improve the classification accuracy. Two cases of HAR are tested using a classification model trained with shadow features: one is by using wearable sensor and the other is by a Kinect-based remote sensor. Our experiments can demonstrate the advantages of the new method, which will have an impact on human activity detection research.

  1. 25 CFR 170.623 - How are IRR Program projects and activities included in a self-governance agreement?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false How are IRR Program projects and activities included in a self-governance agreement? 170.623 Section 170.623 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE... self-governance agreement? To include an IRR Program project or activity in a self-governance agreement...

  2. Increasing the Lifetime of Mobile WSNs via Dynamic Optimization of Sensor Node Communication Activity

    Directory of Open Access Journals (Sweden)

    Dayan Adionel Guimarães

    2016-09-01

    Full Text Available In this paper, a simple and flexible method for increasing the lifetime of fixed or mobile wireless sensor networks is proposed. Based on past residual energy information reported by the sensor nodes, the sink node or another central node dynamically optimizes the communication activity levels of the sensor nodes to save energy without sacrificing the data throughput. The activity levels are defined to represent portions of time or time-frequency slots in a frame, during which the sensor nodes are scheduled to communicate with the sink node to report sensory measurements. Besides node mobility, it is considered that sensors’ batteries may be recharged via a wireless power transmission or equivalent energy harvesting scheme, bringing to the optimization problem an even more dynamic character. We report large increased lifetimes over the non-optimized network and comparable or even larger lifetime improvements with respect to an idealized greedy algorithm that uses both the real-time channel state and the residual energy information.

  3. A monolithic active pixel sensor for particle detection in 0.25 μm CMOS technology

    International Nuclear Information System (INIS)

    Velthuis, J.J.; Allport, P.P.; Casse, G.; Evans, A.; Turchetta, R.; Villani, G.

    2006-01-01

    We are developing CMOS monolithic active pixel sensors (MAPS) for High Energy Physics applications. We have successfully produced 3 test structures. They feature several different pixel types including: standard 3MOS, 4MOS allowing Correlated Double Sampling (CDS), charge amplifier pixels and a flexible APS (FAPS). The FAPS has a 10 deep pipeline on each pixel. This is specifically designed with the beam structure of the TESLA proposal for the Linear Collider in mind. Results of a laser test on our first device and source test results on two more recent test structures will be presented

  4. Activity behavior of a HPLC column including α-chymotrypsin immobilized monosized-porous particles

    International Nuclear Information System (INIS)

    Bilici, Z.; Camli, S.T.; Unsal, E.; Tuncel, A.

    2004-01-01

    In this study, a polymer-based, α-chymotrypsin (CT) immobilized HPLC column was prepared as a potential material for affinity-HPLC and chiral separation applications. Monosized-macroporous particles were synthesized as the support material by a relatively new polymerization protocol, the so-called, 'modified seeded polymerization'. The particles were obtained in the form of styrene-glycidyl methacrylate- divinylbenzene terpolymer approximately 11 μm in size. The particles were treated with aqueous ammonia to have primary amine groups on the porous surface. The amine functionalized particles were reacted by glutaraldehyde and the enzyme, CT, was covalently attached. CT carrying monosized-porous particles were slurry packed into the HPLC column 50 mmx4.6 mm in size. Since the activity behavior of immobilized CT played an important role in the enantiomeric separations performed by similar columns, the enzymatic activity behavior of the column produced by our protocol was determined. For this purpose, HPLC column was used as a packed bed reactor and the enzymatic reaction was continuously followed by measuring the absorbance of the output flow by the UV-detector of HPLC. S-shaped absorbance-time curves were obtained by monitoring the reactor output both in dynamic and steady-state periods. The columns with relatively lower immobilized enzyme content were more sensitive to the changes in the operating conditions and responded with more appreciable substrate conversion changes. The maximum reaction rate of the immobilized enzyme was estimated as approximately 25% of the free one by the mathematical model describing the activity behavior of the column. No significant loss was observed in the activity of the immobilized enzyme during the course of the experiments

  5. Ex Vivo Activity of Endoperoxide Antimalarials, Including Artemisone and Arterolane, against Multidrug-Resistant Plasmodium falciparum Isolates from Cambodia

    Science.gov (United States)

    2014-10-01

    OCT 2014 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Ex Vivo Activity of Endoperoxide Antimalarials , Including Artemisone...Prescribed by ANSI Std Z39-18 Ex Vivo Activity of Endoperoxide Antimalarials , Including Artemisone and Arterolane, against Multidrug-Resistant...potent antimalarial activity (2, 3). Despite having a rapid mecha- nism of action, artemisinin resistance eventually emerged and was first detected

  6. Telemetered sensors for dynamic activity and structural performance monitoring

    Science.gov (United States)

    Townsend, Christopher P.; Hamel, Michael J.; Arms, Steven W.

    2001-08-01

    The development of improved structures requires knowledge of their dynamic behavior. Minimally intrusive wireless systems, capable of monitoring vibration and impact, are needed in order to provide this knowledge. Our objective was to design, build, and test a high speed data collection and wireless data communications system, including microsensors, and capable of being embedded or externally worn. Our previous transmitter designs were small and could be used to transmit multichannel digital data, but they were not capable of fast data transmission rates. The addition of a remotely triggered datalogger allowed us to overcome the limitations of our earlier designs. A bi-directional RF communications link was used to trigger a sample to be logged (from 30 meters), as well as to request data to be transmitted to the host PC for data acquisition/analysis. Sweep rates of 2000 Hz were successfully demonstrated from a triad of MEMs accelerometers. The remote datalogger and transceiver and accelerometer package measured 12 mm by 24 mm by 6 mm thick; these were mounted to the feet of thoroughbred horses to study their impact levels. These small, fast, wireless data recording systems can be used to monitor rotating/ vibrating machinery and civil/automotive/aerospace structures.

  7. Highly sensitive glucose sensor based on monodisperse palladium nickel/activated carbon nanocomposites.

    Science.gov (United States)

    Koskun, Yağmur; Şavk, Aysun; Şen, Betül; Şen, Fatih

    2018-06-20

    Glucose enzyme biosensors have been used for a variety of applications such as medical diagnosis, bioprocess engineering, beverage industry and environmental scanning etc. and there is still a growing interest in glucose sensors. For this purpose, addressed herein, as a novel glucose sensor, highly sensitive activated carbon (AC) decorated monodisperse nickel and palladium alloy nanocomposites modified glassy carbon electrode (Ni-Pd@AC/GCE NCs) have been synthesized by in-situ reduction technique. Raman Spectroscopy (RS), X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), cyclic voltammetry (CV) and chronoamperometry (CA) were used for the characterization of the prepared non-enzymatic glucose sensor. The characteristic sensor properties of the Ni-Pd@AC/GCE electrode were compared with Ni-Pd NCs/GCE, Ni@AC/GCE and Pd@AC/GCE and the results demonstrate that the AC is very effective in the enhancement of the electrocatalytic properties of sensor. In addition, the Ni-Pd@AC/GCE nanocomposites showed a very low detection limit of 0.014 μM, a wide linear range of 0.01 mM-1 mM and a very high sensitivity of 90 mA mM -1  cm -2 . Furthermore, the recommended sensor offer the various advantageous such as facile preparation, fast response time, high selectivity and sensitivity. Lastly, monodisperse Ni-Pd@AC/GCE was utilized to detect glucose in real sample species. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. A Sensitive Dynamic and Active Pixel Vision Sensor for Color or Neural Imaging Applications.

    Science.gov (United States)

    Moeys, Diederik Paul; Corradi, Federico; Li, Chenghan; Bamford, Simeon A; Longinotti, Luca; Voigt, Fabian F; Berry, Stewart; Taverni, Gemma; Helmchen, Fritjof; Delbruck, Tobi

    2018-02-01

    Applications requiring detection of small visual contrast require high sensitivity. Event cameras can provide higher dynamic range (DR) and reduce data rate and latency, but most existing event cameras have limited sensitivity. This paper presents the results of a 180-nm Towerjazz CIS process vision sensor called SDAVIS192. It outputs temporal contrast dynamic vision sensor (DVS) events and conventional active pixel sensor frames. The SDAVIS192 improves on previous DAVIS sensors with higher sensitivity for temporal contrast. The temporal contrast thresholds can be set down to 1% for negative changes in logarithmic intensity (OFF events) and down to 3.5% for positive changes (ON events). The achievement is possible through the adoption of an in-pixel preamplification stage. This preamplifier reduces the effective intrascene DR of the sensor (70 dB for OFF and 50 dB for ON), but an automated operating region control allows up to at least 110-dB DR for OFF events. A second contribution of this paper is the development of characterization methodology for measuring DVS event detection thresholds by incorporating a measure of signal-to-noise ratio (SNR). At average SNR of 30 dB, the DVS temporal contrast threshold fixed pattern noise is measured to be 0.3%-0.8% temporal contrast. Results comparing monochrome and RGBW color filter array DVS events are presented. The higher sensitivity of SDAVIS192 make this sensor potentially useful for calcium imaging, as shown in a recording from cultured neurons expressing calcium sensitive green fluorescent protein GCaMP6f.

  9. Silicon-on-insulator (SOI) active pixel sensors with the photosite implemented in the substrate

    Science.gov (United States)

    Zheng, Xinyu (Inventor); Pain, Bedabrata (Inventor)

    2005-01-01

    Active pixel sensors for a high quality imager are fabricated using a silicon-on-insulator (SOI) process by integrating the photodetectors on the SOI substrate and forming pixel readout transistors on the SOI thin-film. The technique can include forming silicon islands on a buried insulator layer disposed on a silicon substrate and selectively etching away the buried insulator layer over a region of the substrate to define a photodetector area. Dopants of a first conductivity type are implanted to form a signal node in the photodetector area and to form simultaneously drain/source regions for a first transistor in at least a first one of the silicon islands. Dopants of a second conductivity type are implanted to form drain/source regions for a second transistor in at least a second one of the silicon islands. Isolation rings around the photodetector also can be formed when dopants of the second conductivity type are implanted. Interconnections among the transistors and the photodetector are provided to allow signals sensed by the photodetector to be read out via the transistors formed on the silicon islands.

  10. Active immunisation of horses against tetanus including the booster dose and its application.

    Science.gov (United States)

    Liefman, C E

    1981-02-01

    Successful active immunisation of horses against tetanus is dependent on a number of factors of which the toxoid preparation used, its method of application and the ability of the individual horse to respond are fundamental. Two immunisation schedules using an aluminium-based toxoid preparation were examined and the protection determined by monitoring the level of antitoxin afforded by each schedule. The results obtained demonstrated that 2 doses of this toxoid are necessary to ensure 12 months protection in all horses. These results are discussed in relation to the factors involved in active immunisation against tetanus. Reference is also made to the occurrence of a transient phase of reduced levels of antitoxin following booster doses of toxoid in immunised horses during which it is considered these horses could become more susceptible to tetanus. The effect of a booster dose on immunised horses was examined and while there can be a reduction in the level of antitoxin in some immunised horses following this dose its effect is minimal, short-lived and for all practical purposes can be disregarded. The application of the booster dose in practice is also discussed.

  11. In vitro activity of Inula helenium against clinical Staphylococcus aureus strains including MRSA.

    LENUS (Irish Health Repository)

    O'Shea, S

    2009-01-01

    The present study aims to investigate the bactericidal activity (specifically antistaphylococcal) of Inula helenium. The antimicrobial activity of the extract is tested against 200 clinically significant Irish Staphylococcus aureus isolates consisting of methicillin-resistant (MRSA) and -sensitive (MSSA) S. aureus using a drop test method and a microbroth dilution method. The antibacterial effect is evaluated by measuring the area of the inhibition zone against the isolates. Results proved I. helenium to be 100% effective against the 200 staphylococci tested, with 93% of isolates falling within the ++ and +++ groups. The minimum bactericidal concentration of I. helenium was examined on a subset of isolates and values ranged from 0.9 mg\\/mL to 9.0 mg\\/mL. The extract was equally effective against antibiotic-resistant and -sensitive strains. This plant therefore possesses compounds with potent antistaphylococcal properties, which in the future could be used to complement infection control policies and prevent staphylococcal infection and carriage. This research supports other studies wherein herbal plants exhibiting medicinal properties are being examined to overcome the problems of antibiotic resistance and to offer alternatives in the treatment and control of infectious diseases.

  12. A Human Activity Recognition System Using Skeleton Data from RGBD Sensors.

    Science.gov (United States)

    Cippitelli, Enea; Gasparrini, Samuele; Gambi, Ennio; Spinsante, Susanna

    2016-01-01

    The aim of Active and Assisted Living is to develop tools to promote the ageing in place of elderly people, and human activity recognition algorithms can help to monitor aged people in home environments. Different types of sensors can be used to address this task and the RGBD sensors, especially the ones used for gaming, are cost-effective and provide much information about the environment. This work aims to propose an activity recognition algorithm exploiting skeleton data extracted by RGBD sensors. The system is based on the extraction of key poses to compose a feature vector, and a multiclass Support Vector Machine to perform classification. Computation and association of key poses are carried out using a clustering algorithm, without the need of a learning algorithm. The proposed approach is evaluated on five publicly available datasets for activity recognition, showing promising results especially when applied for the recognition of AAL related actions. Finally, the current applicability of this solution in AAL scenarios and the future improvements needed are discussed.

  13. A Human Activity Recognition System Using Skeleton Data from RGBD Sensors

    Directory of Open Access Journals (Sweden)

    Enea Cippitelli

    2016-01-01

    Full Text Available The aim of Active and Assisted Living is to develop tools to promote the ageing in place of elderly people, and human activity recognition algorithms can help to monitor aged people in home environments. Different types of sensors can be used to address this task and the RGBD sensors, especially the ones used for gaming, are cost-effective and provide much information about the environment. This work aims to propose an activity recognition algorithm exploiting skeleton data extracted by RGBD sensors. The system is based on the extraction of key poses to compose a feature vector, and a multiclass Support Vector Machine to perform classification. Computation and association of key poses are carried out using a clustering algorithm, without the need of a learning algorithm. The proposed approach is evaluated on five publicly available datasets for activity recognition, showing promising results especially when applied for the recognition of AAL related actions. Finally, the current applicability of this solution in AAL scenarios and the future improvements needed are discussed.

  14. Nuclear Rocket Test Facility Decommissioning Including Controlled Explosive Demolition of a Neutron-Activated Shield Wall

    International Nuclear Information System (INIS)

    Michael Kruzic

    2007-01-01

    Located in Area 25 of the Nevada Test Site, the Test Cell A Facility was used in the 1960s for the testing of nuclear rocket engines, as part of the Nuclear Rocket Development Program. The facility was decontaminated and decommissioned (D and D) in 2005 using the Streamlined Approach For Environmental Restoration (SAFER) process, under the Federal Facilities Agreement and Consent Order (FFACO). Utilities and process piping were verified void of contents, hazardous materials were removed, concrete with removable contamination decontaminated, large sections mechanically demolished, and the remaining five-foot, five-inch thick radiologically-activated reinforced concrete shield wall demolished using open-air controlled explosive demolition (CED). CED of the shield wall was closely monitored and resulted in no radiological exposure or atmospheric release

  15. Sixty Minutes of Physical Activity per Day Included Within Preschool Academic Lessons Improves Early Literacy.

    Science.gov (United States)

    Kirk, Stacie M; Kirk, Erik P

    2016-03-01

    The effects of increases in physical activity (PA) on early literacy skills in preschool children are not known. Fifty-four African-American preschool children from a low socioeconomic urban Head Start participated over 8 months. A 2-group, quasi-experimental design was used with one preschool site participating in the PA intervention and a second site participating as the control site. The PA program was designed to promote 300 minutes/week of moderate to vigorous PA academic lessons. Academic achievement related to early literacy and phonological awareness in the areas of rhyming and alliteration were assessed at baseline, 4 and 8 months. Over 8 months, rhyming significantly (p literacy. © 2016, American School Health Association.

  16. ALPIDE, the Monolithic Active Pixel Sensor for the ALICE ITS upgrade

    Science.gov (United States)

    Mager, M.; ALICE Collaboration

    2016-07-01

    A new 10 m2 inner tracking system based on seven concentric layers of Monolithic Active Pixel Sensors will be installed in the ALICE experiment during the second long shutdown of LHC in 2019-2020. The monolithic pixel sensors will be fabricated in the 180 nm CMOS Imaging Sensor process of TowerJazz. The ALPIDE design takes full advantage of a particular process feature, the deep p-well, which allows for full CMOS circuitry within the pixel matrix, while at the same time retaining the full charge collection efficiency. Together with the small feature size and the availability of six metal layers, this allowed a continuously active low-power front-end to be placed into each pixel and an in-matrix sparsification circuit to be used that sends only the addresses of hit pixels to the periphery. This approach led to a power consumption of less than 40 mWcm-2, a spatial resolution of around 5 μm, a peaking time of around 2 μs, while being radiation hard to some 1013 1 MeVneq /cm2, fulfilling or exceeding the ALICE requirements. Over the last years of R & D, several prototype circuits have been used to verify radiation hardness, and to optimize pixel geometry and in-pixel front-end circuitry. The positive results led to a submission of full-scale (3 cm×1.5 cm) sensor prototypes in 2014. They are being characterized in a comprehensive campaign that also involves several irradiation and beam tests. A summary of the results obtained and prospects towards the final sensor to instrument the ALICE Inner Tracking System are given.

  17. Development of active edge pixel sensors and four-side buttable modules using vertical integration technologies

    CERN Document Server

    INSPIRE-00219560; Moser, H.-G.; Nisius, R.; Richter, R.H.; Terzo, S.; Weigell, P.

    2014-01-01

    We present an R&D activity focused on the development of novel modules for the upgrade of the ATLAS pixel system at the High Luminosity LHC (HL-LHC). The modules consist of n-in-p pixel sensors, 100 or 200 $\\mu$m thick, produced at VTT (Finland) with an active edge technology, which considerably reduces the dead area at the periphery of the device. The sensors are interconnected with solder bump-bonding to the ATLAS FE-I3 and FE-I4 read-out chips, and characterized with radioactive sources and beam tests at the CERN-SPS and DESY. The results of these measurements will be discussed for devices before and after irradiation up to a fluence of $5\\times 10^{15}$ \

  18. Active Bio-sensor System, Compatible with Arm Muscle Movement or Blinking Signals in BCI Application

    Directory of Open Access Journals (Sweden)

    Saeid Mehrkanoon

    2008-05-01

    Full Text Available This paper addresses a bionic active sensor system for the BCI application. Proposed system involves analog and digital parts. Two types of accurate sensors are used to pickup the blinking and muscle movement signals. A precision micro-power instrumentation amplifier with the adjustable gain, a sixth order low pass active filter with cutoff frequency 0.1 Hz, and a sixth order band pas filter with the bandwidth of 2-6 Hz are constructed to provide the clean blinking and arm muscle movement signals. TMS320C25 DSP processor is used for independent and unique command signals which are prepared for BCI application by a power amplifier and driver.

  19. FM-CW radar sensors for vital signs and motor activity monitoring

    Directory of Open Access Journals (Sweden)

    Octavian Adrian Postolache

    2011-12-01

    Full Text Available The article summarizes on-going research on vital signs and motor activity monitoring based on radar sensors embedded in wheelchairs, walkers and crutches for in home rehabilitation. Embedded sensors, conditioning circuits, real-time platforms that perform data acquisition, auto-identification, primary data processing and data communication contribute to convert daily used objects in home rehabilitation into smart objects that can be accessed by caregivers during the training sessions through human–machine interfaces expressed by the new generation of smart phones or tablet computers running Android OS or iOS operating systems. The system enables the management of patients in home rehabilitation by providing more accurate and up-to-date information using pervasive computing of vital signs and motor activity records.

  20. porewater chemistry experiment at Mont Terri rock laboratory. Reactive transport modelling including bacterial activity

    International Nuclear Information System (INIS)

    Tournassat, Christophe; Gaucher, Eric C.; Leupin, Olivier X.; Wersin, Paul

    2010-01-01

    Document available in extended abstract form only. An in-situ test in the Opalinus Clay formation, termed pore water Chemistry (PC) experiment, was run for a period of five years. It was based on the concept of diffusive equilibration whereby traced water with a composition close to that expected in the formation was continuously circulated and monitored in a packed off borehole. The main original focus was to obtain reliable data on the pH/pCO 2 of the pore water, but because of unexpected microbially- induced redox reactions, the objective was then changed to elucidate the biogeochemical processes happening in the borehole and to understand their impact on pH/pCO 2 and pH in the low permeability clay formation. The biologically perturbed chemical evolution of the PC experiment was simulated with reactive transport models. The aim of this modelling exercise was to develop a 'minimal-' model able to reproduce the chemical evolution of the PC experiment, i.e. the chemical evolution of solute inorganic and organic compounds (organic carbon, dissolved inorganic carbon etc...) that are coupled with each other through the simultaneous occurrence of biological transformation of solute or solid compounds, in-diffusion and out-diffusion of solute species and precipitation/dissolution of minerals (in the borehole and in the formation). An accurate description of the initial chemical conditions in the surrounding formation together with simplified kinetics rule mimicking the different phases of bacterial activities allowed reproducing the evolution of all main measured parameters (e.g. pH, TOC). Analyses from the overcoring and these simulations evidence the high buffer capacity of Opalinus clay regarding chemical perturbations due to bacterial activity. This pH buffering capacity is mainly attributed to the carbonate system as well as to the clay surfaces reactivity. Glycerol leaching from the pH-electrode might be the primary organic source responsible for

  1. Ozone control of biological activity during Earth's history, including the KT catastrophe

    Science.gov (United States)

    Sheldon, W. R.

    1994-01-01

    There have been brief periods since the beginning of the Cambrian some 600 m.y. ago when mass extinctions destroyed a significant fraction of living species. The most widely studied of these events is the catastrophe at the KT boundary that ended the long dominance of the dinosaurs. In addition to mass extinctions, there is another profound discontinuity in the history of Earth's biota, the explosion of life at the end of the Precambrian era which is an episode that is not explained well at all. For some 3 b.y. before the Cambrian, life had been present on Earth, but maintained a low level of activity which is an aspect of the biota that is puzzling, especially during the last two-thirds of that period. During the last 2 b.y. before the Cambrian, conditions at the Earth's surface were suitable for a burgeoning of the biota, according to most criteria: the oceans neither boiled nor were fozen solid during this time, and the atmosphere contained sufficient O for the development of animals. The purpose of this paper is to suggest that mass extinctions and the lackluster behavior of the Precambrian biota share a common cause: an inadequate amount of ozone in the atmosphere.

  2. A novel source–drain follower for monolithic active pixel sensors

    Energy Technology Data Exchange (ETDEWEB)

    Gao, C., E-mail: chaosong.gao@mails.ccnu.edu.cn [Central China Normal University, Wuhan (China); Aglieri, G.; Hillemanns, H. [CERN, Geneva (Switzerland); Huang, G., E-mail: gmhuang@phy.ccnu.edu.cn [Central China Normal University, Wuhan (China); Junique, A.; Keil, M. [CERN, Geneva (Switzerland); Kim, D. [Dongguk University, Seoul (Korea, Republic of); Yonsei University, Seoul (Korea, Republic of); Kofarago, M.; Kugathasan, T.; Mager, M.; Marin Tobon, C.A.; Martinengo, P. [CERN, Geneva (Switzerland); Mugnier, H. [Mind, Archamps (France); Musa, L. [CERN, Geneva (Switzerland); Lee, S. [Dongguk University, Seoul (Korea, Republic of); Yonsei University, Seoul (Korea, Republic of); Reidt, F. [CERN, Geneva (Switzerland); Ruprecht-Karls-Universitat Heidelberg, Heidelberg (Germany); Riedler, P. [CERN, Geneva (Switzerland); Rousset, J. [Mind, Archamps (France); Sielewicz, K.M. [CERN, Geneva (Switzerland); Warsaw University of Technology, Warsaw (Poland); Snoeys, W. [CERN, Geneva (Switzerland); and others

    2016-09-21

    Monolithic active pixel sensors (MAPS) receive interest in tracking applications in high energy physics as they integrate sensor and readout electronics in one silicon die with potential for lower material budget and cost, and better performance. Source followers (SFs) are widely used for MAPS readout: they increase charge conversion gain 1/C{sub eff} or decrease the effective sensing node capacitance C{sub eff} because the follower action compensates part of the input capacitance. Charge conversion gain is critical for analog power consumption and therefore for material budget in tracking applications, and also has direct system impact. This paper presents a novel source–drain follower (SDF), where both source and drain follow the gate potential improving charge conversion gain. For the inner tracking system (ITS) upgrade of the ALICE experiment at CERN, low material budget is a primary requirement. The SDF circuit was studied as part of the effort to optimize the effective capacitance of the sensing node. The collection electrode, input transistor and routing metal all contribute to C{sub eff}. Reverse sensor bias reduces the collection electrode capacitance. The novel SDF circuit eliminates the contribution of the input transistor to C{sub eff}, reduces the routing contribution if additional shielding is introduced, provides a way to estimate the capacitance of the sensor itself, and has a voltage gain closer to unity than the standard SF. The SDF circuit has a somewhat larger area with a somewhat smaller bandwidth, but this is acceptable in most cases. A test chip, manufactured in a 180 nm CMOS image sensor process, implements small prototype pixel matrices in different flavors to compare the standard SF to the novel SF and to the novel SF with additional shielding. The effective sensing node capacitance was measured using a {sup 55}Fe source. Increasing reverse substrate bias from −1 V to −6 V reduces C{sub eff} by 38% and the equivalent noise charge

  3. A novel source–drain follower for monolithic active pixel sensors

    International Nuclear Information System (INIS)

    Gao, C.; Aglieri, G.; Hillemanns, H.; Huang, G.; Junique, A.; Keil, M.; Kim, D.; Kofarago, M.; Kugathasan, T.; Mager, M.; Marin Tobon, C.A.; Martinengo, P.; Mugnier, H.; Musa, L.; Lee, S.; Reidt, F.; Riedler, P.; Rousset, J.; Sielewicz, K.M.; Snoeys, W.

    2016-01-01

    Monolithic active pixel sensors (MAPS) receive interest in tracking applications in high energy physics as they integrate sensor and readout electronics in one silicon die with potential for lower material budget and cost, and better performance. Source followers (SFs) are widely used for MAPS readout: they increase charge conversion gain 1/C_e_f_f or decrease the effective sensing node capacitance C_e_f_f because the follower action compensates part of the input capacitance. Charge conversion gain is critical for analog power consumption and therefore for material budget in tracking applications, and also has direct system impact. This paper presents a novel source–drain follower (SDF), where both source and drain follow the gate potential improving charge conversion gain. For the inner tracking system (ITS) upgrade of the ALICE experiment at CERN, low material budget is a primary requirement. The SDF circuit was studied as part of the effort to optimize the effective capacitance of the sensing node. The collection electrode, input transistor and routing metal all contribute to C_e_f_f. Reverse sensor bias reduces the collection electrode capacitance. The novel SDF circuit eliminates the contribution of the input transistor to C_e_f_f, reduces the routing contribution if additional shielding is introduced, provides a way to estimate the capacitance of the sensor itself, and has a voltage gain closer to unity than the standard SF. The SDF circuit has a somewhat larger area with a somewhat smaller bandwidth, but this is acceptable in most cases. A test chip, manufactured in a 180 nm CMOS image sensor process, implements small prototype pixel matrices in different flavors to compare the standard SF to the novel SF and to the novel SF with additional shielding. The effective sensing node capacitance was measured using a "5"5Fe source. Increasing reverse substrate bias from −1 V to −6 V reduces C_e_f_f by 38% and the equivalent noise charge (ENC) by 22% for the

  4. Systematic approach to development of pressure sensors using dielectric electro-active polymer membranes

    International Nuclear Information System (INIS)

    York, A; Seelecke, S; Dunn, J

    2013-01-01

    Dielectric electro-active polymers (DEAPs) have become attractive materials for various actuation and sensing applications due to their high energy and power density, high efficiency, light weight, and fast response speed. However, commercial development has been hindered due to a variety of constraints such as reliability, non-linear behavior, cost of driving electronics, and form factor requirements. This paper presents the systematic development from laboratory concept to commercial readiness of a novel pressure sensing system using a DEAP membrane. The pressure sensing system was designed for in-line pressure measurements for low pressure applications such as health systems monitoring. A first generation sensor was designed, built and tested with a focus on the qualitative capabilities of EAP membranes as sensors. Experimental measurements were conducted that demonstrated the capability of the sensor to output a voltage signal proportional to a changing pressure. Several undesirable characteristics were observed during these initial tests such as strong hysteresis, non-linearity, very limited pressure range, and low fatigue life. A second generation prototype was then designed to remove or compensate for these undesirable characteristics. This prototype was then built and tested. The new design showed an almost complete removal of hysteretic non-linear effects and was capable of operating at 10 × the pressure range of the initial generation. This new design is the framework for a novel DEAP based pressure sensor ready for commercial applications. (paper)

  5. Functional characterization of planar sensors with active edges using laser and X-ray beam scans

    International Nuclear Information System (INIS)

    Povoli, M.; Bagolini, A.; Boscardin, M.; Dalla Betta, G.-F.; Giacomini, G.; Hasi, J.; Oh, A.; Zorzi, N.

    2013-01-01

    We report on the functional characterization of planar sensors with active edges fabricated at Fondazione Bruno Kessler (FBK), Trento, Italy. The measurements here reported were performed by means of laser and X-ray beam scans mainly focusing on the signal efficiency of the edge region of the devices. Results are very encouraging and show very good sensitivity up to few microns away from the device physical edge

  6. Functional characterization of planar sensors with active edges using laser and X-ray beam scans

    Energy Technology Data Exchange (ETDEWEB)

    Povoli, M., E-mail: povoli@disi.unitn.it [Dipartimento di Ingegneria e Scienza dell' Informazione, Università di Trento, Via Sommarive, 14, I-38123 Povo di Trento (Italy); INFN, Sezione di Padova (Gruppo Collegato di Trento),Via Sommarive, 14, I-38123 Povo di Trento (Italy); Bagolini, A.; Boscardin, M. [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive, 18, I-38123 Povo di Trento (Italy); Dalla Betta, G.-F. [Dipartimento di Ingegneria e Scienza dell' Informazione, Università di Trento, Via Sommarive, 14, I-38123 Povo di Trento (Italy); INFN, Sezione di Padova (Gruppo Collegato di Trento),Via Sommarive, 14, I-38123 Povo di Trento (Italy); Giacomini, G. [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive, 18, I-38123 Povo di Trento (Italy); Hasi, J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025-7015 (United States); Oh, A. [The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Zorzi, N. [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive, 18, I-38123 Povo di Trento (Italy)

    2013-08-01

    We report on the functional characterization of planar sensors with active edges fabricated at Fondazione Bruno Kessler (FBK), Trento, Italy. The measurements here reported were performed by means of laser and X-ray beam scans mainly focusing on the signal efficiency of the edge region of the devices. Results are very encouraging and show very good sensitivity up to few microns away from the device physical edge.

  7. Linear variable differential transformer sensor using glass-covered amorphous wires as active core

    International Nuclear Information System (INIS)

    Chiriac, H.; Hristoforou, E.; Neagu, Maria; Pieptanariu, M.

    2000-01-01

    Results concerning linear variable differential transformer (LVDT) displacement sensor using as movable core glass-covered amorphous wires are presented. The LVDT response is linear for a displacement of the movable core up to about 14 mm, with an accuracy of 1 μm. LVDT using glass-covered amorphous wire as an active core presents a high sensitivity and good mechanical and corrosion resistance

  8. Electrocatalytic cermet sensor

    Science.gov (United States)

    Shoemaker, Erika L.; Vogt, Michael C.

    1998-01-01

    A sensor for O.sub.2 and CO.sub.2 gases. The gas sensor includes a plurality of layers driven by a cyclic voltage to generate a unique plot characteristic of the gas in contact with the sensor. The plurality of layers includes an alumina substrate, a reference electrode source of anions, a lower electrical reference electrode of Pt coupled to the reference source of anions, a solid electrolyte containing tungsten and coupled to the lower reference electrode, a buffer layer for preventing flow of Pt ions into the solid electrolyte and an upper catalytically active Pt electrode coupled to the buffer layer.

  9. Development of active edge pixel sensors and four-side buttable modules using vertical integration technologies

    Energy Technology Data Exchange (ETDEWEB)

    Macchiolo, A., E-mail: Anna.Macchiolo@mpp.mpg.de [Max-Planck-Institut for Physics, Föhringer Ring 6, D-80805 Munich (Germany); Andricek, L. [Semiconductor Laboratory of the Max-Planck-Society, Otto Hahn Ring 6, D-81739 Munich (Germany); Moser, H.-G.; Nisius, R. [Max-Planck-Institut for Physics, Föhringer Ring 6, D-80805 Munich (Germany); Richter, R.H. [Semiconductor Laboratory of the Max-Planck-Society, Otto Hahn Ring 6, D-81739 Munich (Germany); Terzo, S.; Weigell, P. [Max-Planck-Institut for Physics, Föhringer Ring 6, D-80805 Munich (Germany)

    2014-11-21

    We present an R and D activity focused on the development of novel modules for the upgrade of the ATLAS pixel system at the High Luminosity LHC (HL-LHC). The modules consist of n-in-p pixel sensors, 100 or 200 μm thick, produced at VTT (Finland) with an active edge technology, which considerably reduces the dead area at the periphery of the device. The sensors are interconnected with solder bump-bonding to the ATLAS FE-I3 and FE-I4 read-out chips, and characterised with radioactive sources and beam tests at the CERN-SPS and DESY. The results of these measurements will be discussed for devices before and after irradiation up to a fluence of 5×10{sub 15}n{sub eq}/cm{sup 2}. We will also report on the R and D activity to obtain Inter Chip Vias (ICVs) on the ATLAS read-out chip in collaboration with the Fraunhofer Institute EMFT. This step is meant to prove the feasibility of the signal transport to the newly created readout pads on the backside of the chips allowing for four side buttable devices without the presently used cantilever for wire bonding. The read-out chips with ICVs will be interconnected to thin pixel sensors, 75 μm and 150 μm thick, with the Solid Liquid Interdiffusion (SLID) technology, which is an alternative to the standard solder bump-bonding.

  10. Testing the effectiveness of automated acoustic sensors for monitoring vocal activity of Marbled Murrelets Brachyramphus marmoratus

    Science.gov (United States)

    Cragg, Jenna L.; Burger, Alan E.; Piatt, John F.

    2015-01-01

    Cryptic nest sites and secretive breeding behavior make population estimates and monitoring of Marbled Murrelets Brachyramphus marmoratus difficult and expensive. Standard audio-visual and radar protocols have been refined but require intensive field time by trained personnel. We examined the detection range of automated sound recorders (Song Meters; Wildlife Acoustics Inc.) and the reliability of automated recognition models (“recognizers”) for identifying and quantifying Marbled Murrelet vocalizations during the 2011 and 2012 breeding seasons at Kodiak Island, Alaska. The detection range of murrelet calls by Song Meters was estimated to be 60 m. Recognizers detected 20 632 murrelet calls (keer and keheer) from a sample of 268 h of recordings, yielding 5 870 call series, which compared favorably with human scanning of spectrograms (on average detecting 95% of the number of call series identified by a human observer, but not necessarily the same call series). The false-negative rate (percentage of murrelet call series that the recognizers failed to detect) was 32%, mainly involving weak calls and short call series. False-positives (other sounds included by recognizers as murrelet calls) were primarily due to complex songs of other bird species, wind and rain. False-positives were lower in forest nesting habitat (48%) and highest in shrubby vegetation where calls of other birds were common (97%–99%). Acoustic recorders tracked spatial and seasonal trends in vocal activity, with higher call detections in high-quality forested habitat and during late July/early August. Automated acoustic monitoring of Marbled Murrelet calls could provide cost-effective, valuable information for assessing habitat use and temporal and spatial trends in nesting activity; reliability is dependent on careful placement of sensors to minimize false-positives and on prudent application of digital recognizers with visual checking of spectrograms.

  11. Physical activity discrimination improvement using accelerometers and wireless sensor network localization - biomed 2013.

    Science.gov (United States)

    Bashford, Gregory R; Burnfield, Judith M; Perez, Lance C

    2013-01-01

    Automating documentation of physical activity data (e.g., duration and speed of walking or propelling a wheelchair) into the electronic medical record (EMR) offers promise for improving efficiency of documentation and understanding of best practices in the rehabilitation and home health settings. Commercially available devices which could be used to automate documentation of physical activities are either cumbersome to wear or lack the specificity required to differentiate activities. We have designed a novel system to differentiate and quantify physical activities, using inexpensive accelerometer-based biomechanical data technology and wireless sensor networks, a technology combination that has not been used in a rehabilitation setting to date. As a first step, a feasibility study was performed where 14 healthy young adults (mean age = 22.6 ± 2.5 years, mean height = 173 ± 10.0 cm, mean mass = 70.7 ± 11.3 kg) carried out eight different activities while wearing a biaxial accelerometer sensor. Activities were performed at each participant’s self-selected pace during a single testing session in a controlled environment. Linear discriminant analysis was performed by extracting spectral parameters from the subjects’ accelerometer patterns. It is shown that physical activity classification alone results in an average accuracy of 49.5%, but when combined with rule-based constraints using a wireless sensor network with localization capabilities in an in silico simulated room, accuracy improves to 99.3%. When fully implemented, our technology package is expected to improve goal setting, treatment interventions and patient outcomes by enhancing clinicians’ understanding of patients’ physical performance within a day and across the rehabilitation program.

  12. Signal processing techniques for damage detection with piezoelectric wafer active sensors and embedded ultrasonic structural radar

    Science.gov (United States)

    Yu, Lingyu; Bao, Jingjing; Giurgiutiu, Victor

    2004-07-01

    Embedded ultrasonic structural radar (EUSR) algorithm is developed for using piezoelectric wafer active sensor (PWAS) array to detect defects within a large area of a thin-plate specimen. Signal processing techniques are used to extract the time of flight of the wave packages, and thereby to determine the location of the defects with the EUSR algorithm. In our research, the transient tone-burst wave propagation signals are generated and collected by the embedded PWAS. Then, with signal processing, the frequency contents of the signals and the time of flight of individual frequencies are determined. This paper starts with an introduction of embedded ultrasonic structural radar algorithm. Then we will describe the signal processing methods used to extract the time of flight of the wave packages. The signal processing methods being used include the wavelet denoising, the cross correlation, and Hilbert transform. Though hardware device can provide averaging function to eliminate the noise coming from the signal collection process, wavelet denoising is included to ensure better signal quality for the application in real severe environment. For better recognition of time of flight, cross correlation method is used. Hilbert transform is applied to the signals after cross correlation in order to extract the envelope of the signals. Signal processing and EUSR are both implemented by developing a graphical user-friendly interface program in LabView. We conclude with a description of our vision for applying EUSR signal analysis to structural health monitoring and embedded nondestructive evaluation. To this end, we envisage an automatic damage detection application utilizing embedded PWAS, EUSR, and advanced signal processing.

  13. Detection of protease activity by fluorescent protein FRET sensors: from computer simulation to live cells

    Science.gov (United States)

    Goryashchenko, Alexander S.; Khrenova, Maria G.; Savitsky, Alexander P.

    2018-04-01

    Förster resonance energy transfer (FRET) sensors are widely used for the detection of protease activity in vitro and in vivo. Usually they consist of a FRET pair connected with a polypeptide linker containing a specific cleavage site for the relevant protease. Use of the fluorescent proteins as components of the FRET pair allows genetic encoding of such sensors and solves the problem of their delivery into live cells and animals. There are several ways to improve the properties of such sensors, mainly to increase FRET efficiency and therefore the dynamic range. One of the ways to achieve this is to use a non-fluorescent chromoprotein as an acceptor. Molecular dynamic simulations may assist in the construction of linker structures connecting donor and acceptor molecules. Estimation of the orientation factor κ 2 can be obtained by methods based on quantum theory and combined quantum mechanics/molecular mechanics approaches. The linker can be structured by hydrophobic interactions, bringing it into a closed conformation that shortens the distance between donor and acceptor and, consequently, increases FRET efficiency. We analyzed the effects of different linker structures on the detection of caspase-3 activity using a non-fluorescent acceptor. Also we have constructed the Tb3+- TagRFP sensor in which a complex of the terbium ion and terbium-binding peptide is used as a donor. This allowed us to use the unique property of lanthanide ions—fluorescence lifetime up to milliseconds—to perform measurements with time delay and exclude the nanosecond-order fluorescence. Using our systems as a starting point, by changing the recognition site in the linker it is possible to perform imaging of different protease activity in vitro or in vivo.

  14. 45 CFR 287.130 - Can NEW Program activities include job market assessments, job creation and economic development...

    Science.gov (United States)

    2010-10-01

    ... assessments, job creation and economic development activities? 287.130 Section 287.130 Public Welfare... creation and economic development activities? (a) A Tribe may conduct job market assessments within its NEW Program. These might include the following: (1) Consultation with the Tribe's economic development staff...

  15. X-ray active mirror coupled with a Hartmann wavefront sensor

    International Nuclear Information System (INIS)

    Idir, Mourad; Mercere, Pascal; Modi, Mohammed H.; Dovillaire, Guillaume; Levecq, Xavier; Bucourt, Samuel; Escolano, Lionel; Sauvageot, Paul

    2010-01-01

    This paper reports on the design and performances of a test prototype active X-ray mirror (AXM) which has been designed and manufactured in collaboration with the French Small and Medium Enterprise mechanical company ISP System for the national French storage ring SOLEIL. Coupled with this active X-ray mirror and also in collaboration with another French Small and Medium Enterprise (Imagine Optic) a lot of efforts have been done in order to design and fabricate a wavefront X-ray analyzer based on the Hartmann principle (Hartman wavefront sensor, HWS).

  16. Novel sensors to enable closed-loop active clearance control in gas turbine engines

    Science.gov (United States)

    Geisheimer, Jonathan; Holst, Tom

    2014-06-01

    Active clearance control within the turbine section of gas turbine engines presents and opportunity within aerospace and industrial applications to improve operating efficiencies and the life of downstream components. Open loop clearance control is currently employed during the development of all new large core aerospace engines; however, the ability to measure the gap between the blades and the case and close down the clearance further presents as opportunity to gain even greater efficiencies. The turbine area is one of the harshest environments for long term placement of a sensor in addition to the extreme accuracy requirements required to enable closed loop clearance control. This paper gives an overview of the challenges of clearance measurements within the turbine as well as discusses the latest developments of a microwave sensor designed for this application.

  17. High-fidelity optical reporting of neuronal electrical activity with an ultrafast fluorescent voltage sensor

    Science.gov (United States)

    St-Pierre, François; Marshall, Jesse D; Yang, Ying; Gong, Yiyang; Schnitzer, Mark J; Lin, Michael Z

    2015-01-01

    Accurate optical reporting of electrical activity in genetically defined neuronal populations is a long-standing goal in neuroscience. Here we describe Accelerated Sensor of Action Potentials 1 (ASAP1), a novel voltage sensor design in which a circularly permuted green fluorescent protein is inserted within an extracellular loop of a voltage-sensing domain, rendering fluorescence responsive to membrane potential. ASAP1 demonstrates on- and off- kinetics of 2.1 and 2.0 ms, reliably detects single action potentials and subthreshold potential changes, and tracks trains of action potential waveforms up to 200 Hz in single trials. With a favorable combination of brightness, dynamic range, and speed, ASAP1 enables continuous monitoring of membrane potential in neurons at KHz frame rates using standard epifluorescence microscopy. PMID:24755780

  18. An active cooperation-aware spectrum allocation mechanism for body sensor networks.

    Science.gov (United States)

    Jiang, Fu; Guo, Ying; Peng, Jun; Hu, Jiankun

    2015-01-28

    A cognitive radio-based spectrum allocation scheme using an active cooperative-aware mechanism is proposed in this paper. The scheme ensures that the primary user and secondary users cooperate actively for their own benefits. The primary user releases some spectrum resources to secondary users to actively stimulate them to actively join the cooperative transmission of the primary user, and secondary users help the primary user to relay data in return, as well as its self-data transmission at the same time. The Stackelberg game is used to evenly and jointly optimize the utilities of both the primary and secondary users. Simulation results show that the proposed active cooperation-aware mechanism could improve the body sensor network performance.

  19. An Active Cooperation-Aware Spectrum Allocation Mechanism for Body Sensor Networks

    Directory of Open Access Journals (Sweden)

    Fu Jiang

    2015-01-01

    Full Text Available A cognitive radio-based spectrum allocation scheme using an active cooperative-aware mechanism is proposed in this paper. The scheme ensures that the primary user and secondary users cooperate actively for their own benefits. The primary user releases some spectrum resources to secondary users to actively stimulate them to actively join the cooperative transmission of the primary user, and secondary users help the primary user to relay data in return, as well as its self-data transmission at the same time. The Stackelberg game is used to evenly and jointly optimize the utilities of both the primary and secondary users. Simulation results show that the proposed active cooperation-aware mechanism could improve the body sensor network performance.

  20. Predicting mountain lion activity using radiocollars equipped with mercury tip-sensors

    Science.gov (United States)

    Janis, Michael W.; Clark, Joseph D.; Johnson, Craig

    1999-01-01

    Radiotelemetry collars with tip-sensors have long been used to monitor wildlife activity. However, comparatively few researchers have tested the reliability of the technique on the species being studied. To evaluate the efficacy of using tip-sensors to assess mountain lion (Puma concolor) activity, we radiocollared 2 hand-reared mountain lions and simultaneously recorded their behavior and the associated telemetry signal characteristics. We noted both the number of pulse-rate changes and the percentage of time the transmitter emitted a fast pulse rate (i.e., head up) within sampling intervals ranging from 1-5 minutes. Based on 27 hours of observations, we were able to correctly distinguish between active and inactive behaviors >93% of the time using a logistic regression model. We present several models to predict activity of mountain lions; the selection of which to us would depend on study objectives and logistics. Our results indicate that field protocols that use only pulse-rate changes to indicate activity can lead to significant classification errors.

  1. Extracting aerobic system dynamics during unsupervised activities of daily living using wearable sensor machine learning models.

    Science.gov (United States)

    Beltrame, Thomas; Amelard, Robert; Wong, Alexander; Hughson, Richard L

    2018-02-01

    Physical activity levels are related through algorithms to the energetic demand, with no information regarding the integrity of the multiple physiological systems involved in the energetic supply. Longitudinal analysis of the oxygen uptake (V̇o 2 ) by wearable sensors in realistic settings might permit development of a practical tool for the study of the longitudinal aerobic system dynamics (i.e., V̇o 2 kinetics). This study evaluated aerobic system dynamics based on predicted V̇o 2 data obtained from wearable sensors during unsupervised activities of daily living (μADL). Thirteen healthy men performed a laboratory-controlled moderate exercise protocol and were monitored for ≈6 h/day for 4 days (μADL data). Variables derived from hip accelerometer (ACC HIP ), heart rate monitor, and respiratory bands during μADL were extracted and processed by a validated random forest regression model to predict V̇o 2 . The aerobic system analysis was based on the frequency-domain analysis of ACC HIP and predicted V̇o 2 data obtained during μADL. Optimal samples for frequency domain analysis (constrained to ≤0.01 Hz) were selected when ACC HIP was higher than 0.05 g at a given frequency (i.e., participants were active). The temporal characteristics of predicted V̇o 2 data during μADL correlated with the temporal characteristics of measured V̇o 2 data during laboratory-controlled protocol ([Formula: see text] = 0.82, P system dynamics can be investigated during unsupervised activities of daily living by wearable sensors. Although speculative, these algorithms have the potential to be incorporated into wearable systems for early detection of changes in health status in realistic environments by detecting changes in aerobic response dynamics. NEW & NOTEWORTHY The early detection of subclinical aerobic system impairments might be indicative of impaired physiological reserves that impact the capacity for physical activity. This study is the first to use wearable

  2. Assessment of laboratory and daily energy expenditure estimates from consumer multi-sensor physical activity monitors.

    Science.gov (United States)

    Chowdhury, Enhad A; Western, Max J; Nightingale, Thomas E; Peacock, Oliver J; Thompson, Dylan

    2017-01-01

    Wearable physical activity monitors are growing in popularity and provide the opportunity for large numbers of the public to self-monitor physical activity behaviours. The latest generation of these devices feature multiple sensors, ostensibly similar or even superior to advanced research instruments. However, little is known about the accuracy of their energy expenditure estimates. Here, we assessed their performance against criterion measurements in both controlled laboratory conditions (simulated activities of daily living and structured exercise) and over a 24 hour period in free-living conditions. Thirty men (n = 15) and women (n = 15) wore three multi-sensor consumer monitors (Microsoft Band, Apple Watch and Fitbit Charge HR), an accelerometry-only device as a comparison (Jawbone UP24) and validated research-grade multi-sensor devices (BodyMedia Core and individually calibrated Actiheart™). During discrete laboratory activities when compared against indirect calorimetry, the Apple Watch performed similarly to criterion measures. The Fitbit Charge HR was less consistent at measurement of discrete activities, but produced similar free-living estimates to the Apple Watch. Both these devices underestimated free-living energy expenditure (-394 kcal/d and -405 kcal/d, respectively; P<0.01). The multi-sensor Microsoft Band and accelerometry-only Jawbone UP24 devices underestimated most laboratory activities and substantially underestimated free-living expenditure (-1128 kcal/d and -998 kcal/d, respectively; P<0.01). None of the consumer devices were deemed equivalent to the reference method for daily energy expenditure. For all devices, there was a tendency for negative bias with greater daily energy expenditure. No consumer monitors performed as well as the research-grade devices although in some (but not all) cases, estimates were close to criterion measurements. Thus, whilst industry-led innovation has improved the accuracy of consumer monitors, these devices

  3. Assessment of laboratory and daily energy expenditure estimates from consumer multi-sensor physical activity monitors.

    Directory of Open Access Journals (Sweden)

    Enhad A Chowdhury

    Full Text Available Wearable physical activity monitors are growing in popularity and provide the opportunity for large numbers of the public to self-monitor physical activity behaviours. The latest generation of these devices feature multiple sensors, ostensibly similar or even superior to advanced research instruments. However, little is known about the accuracy of their energy expenditure estimates. Here, we assessed their performance against criterion measurements in both controlled laboratory conditions (simulated activities of daily living and structured exercise and over a 24 hour period in free-living conditions. Thirty men (n = 15 and women (n = 15 wore three multi-sensor consumer monitors (Microsoft Band, Apple Watch and Fitbit Charge HR, an accelerometry-only device as a comparison (Jawbone UP24 and validated research-grade multi-sensor devices (BodyMedia Core and individually calibrated Actiheart™. During discrete laboratory activities when compared against indirect calorimetry, the Apple Watch performed similarly to criterion measures. The Fitbit Charge HR was less consistent at measurement of discrete activities, but produced similar free-living estimates to the Apple Watch. Both these devices underestimated free-living energy expenditure (-394 kcal/d and -405 kcal/d, respectively; P<0.01. The multi-sensor Microsoft Band and accelerometry-only Jawbone UP24 devices underestimated most laboratory activities and substantially underestimated free-living expenditure (-1128 kcal/d and -998 kcal/d, respectively; P<0.01. None of the consumer devices were deemed equivalent to the reference method for daily energy expenditure. For all devices, there was a tendency for negative bias with greater daily energy expenditure. No consumer monitors performed as well as the research-grade devices although in some (but not all cases, estimates were close to criterion measurements. Thus, whilst industry-led innovation has improved the accuracy of consumer monitors

  4. Large-Area High-Performance Flexible Pressure Sensor with Carbon Nanotube Active Matrix for Electronic Skin.

    Science.gov (United States)

    Nela, Luca; Tang, Jianshi; Cao, Qing; Tulevski, George; Han, Shu-Jen

    2018-03-14

    Artificial "electronic skin" is of great interest for mimicking the functionality of human skin, such as tactile pressure sensing. Several important performance metrics include mechanical flexibility, operation voltage, sensitivity, and accuracy, as well as response speed. In this Letter, we demonstrate a large-area high-performance flexible pressure sensor built on an active matrix of 16 × 16 carbon nanotube thin-film transistors (CNT TFTs). Made from highly purified solution tubes, the active matrix exhibits superior flexible TFT performance with high mobility and large current density, along with a high device yield of nearly 99% over 4 inch sample area. The fully integrated flexible pressure sensor operates within a small voltage range of 3 V and shows superb performance featuring high spatial resolution of 4 mm, faster response than human skin (<30 ms), and excellent accuracy in sensing complex objects on both flat and curved surfaces. This work may pave the road for future integration of high-performance electronic skin in smart robotics and prosthetic solutions.

  5. Evaluation of fatigue cracks using nonlinearities of acousto-ultrasonic waves acquired by an active sensor network

    International Nuclear Information System (INIS)

    Zhou, Chao; Hong, Ming; Su, Zhongqing; Wang, Qiang; Cheng, Li

    2013-01-01

    There has been increasing interest in using the nonlinear features of acousto-ultrasonic (AU) waves to detect damage onset (e.g., micro-fatigue cracks) due to their high sensitivity to damage with small dimensions. However, most existing approaches are able to infer the existence of fatigue damage qualitatively, but fail to further ascertain its location and severity. A damage characterization approach, in conjunction with the use of an active piezoelectric sensor network, was established, capable of evaluating fatigue cracks in a quantitative manner (including the co-presence of multiple fatigue cracks, and their individual locations and severities). Fundamental investigations, using both experiment and enhanced finite element analysis dedicated to the simulation of nonlinear AU waves, were carried out to link the accumulation of nonlinearities extracted from high-order AU waves to the characteristic parameters of a fatigue crack. A probability-based diagnostic imaging algorithm was developed, facilitating an intuitive presentation of identification results in images. The approach was verified experimentally by evaluating multi-fatigue cracks near rivet holes of a fatigued aluminum plate, showing satisfactory precision in characterizing real, barely visible fatigue cracks. Compared with existing methods, this approach innovatively (i) uses permanently integrated active sensor networks, conducive to automatic and online health monitoring; (ii) characterizes fatigue cracks at a quantitative level; (iii) allows detection of multiple fatigue cracks; and (iv) visualizes identification results in intuitive images. (paper)

  6. The first fully functional 3D CMOS chip with Deep N-well active pixel sensors for the ILC vertex detector

    International Nuclear Information System (INIS)

    Traversi, G.; Gaioni, L.; Manazza, A.; Manghisoni, M.; Ratti, L.; Re, V.

    2013-01-01

    This work presents the characterization of Deep N-well (DNW) active pixel sensors fabricated in a vertically integrated technology. The DNW approach takes advantage of the triple well structure to lay out a sensor with relatively large charge collecting area (as compared to standard three transistor MAPS), while the readout is performed by a classical signal processing chain for capacitive detectors. This new 3D design relies upon stacking two homogeneous tiers fabricated in a 130 nm CMOS process where the top tier is thinned down to about 12μm to expose through silicon vias (TSV), therefore making connection to the buried circuits possible. This technology has been used to design a fine pitch 3D CMOS sensor with sparsification capabilities, in view of vertexing applications to the International Linear Collider (ILC) experiments. Results from the characterization of different kind of test structures, including single pixels, 3×3 and 8×8 matrices, are presented

  7. Detection of Early Morning Daily Activities with Static Home and Wearable Wireless Sensors

    Directory of Open Access Journals (Sweden)

    David Vanderpool

    2007-10-01

    Full Text Available This paper describes a flexible, cost-effective, wireless in-home activity monitoring system for assisting patients with cognitive impairments due to traumatic brain injury (TBI. The system locates the subject with fixed home sensors and classifies early morning bathroom activities of daily living with a wearable wireless accelerometer. The system extracts time- and frequency-domain features from the accelerometer data and classifies these features with a hybrid classifier that combines Gaussian mixture models and a finite state machine. In particular, the paper establishes that despite similarities between early morning bathroom activities of daily living, it is possible to detect and classify these activities with high accuracy. It also discusses system training and provides data to show that with proper feature selection, accurate detection and classification are possible for any subject with no subject specific training.

  8. Fault Activity Aware Service Delivery in Wireless Sensor Networks for Smart Cities

    Directory of Open Access Journals (Sweden)

    Xiaomei Zhang

    2017-01-01

    Full Text Available Wireless sensor networks (WSNs are increasingly used in smart cities which involve multiple city services having quality of service (QoS requirements. When misbehaving devices exist, the performance of current delivery protocols degrades significantly. Nonetheless, the majority of existing schemes either ignore the faulty behaviors’ variability and time-variance in city environments or focus on homogeneous traffic for traditional data services (simple text messages rather than city services (health care units, traffic monitors, and video surveillance. We consider the problem of fault-aware multiservice delivery, in which the network performs secure routing and rate control in terms of fault activity dynamic metric. To this end, we first design a distributed framework to estimate the fault activity information based on the effects of nondeterministic faulty behaviors and to incorporate these estimates into the service delivery. Then we present a fault activity geographic opportunistic routing (FAGOR algorithm addressing a wide range of misbehaviors. We develop a leaky-hop model and design a fault activity rate-control algorithm for heterogeneous traffic to allocate resources, while guaranteeing utility fairness among multiple city services. Finally, we demonstrate the significant performance of our scheme in routing performance, effective utility, and utility fairness in the presence of misbehaving sensors through extensive simulations.

  9. Monolithic active pixel sensor development for the upgrade of the ALICE inner tracking system

    Science.gov (United States)

    Aglieri, G.; Cavicchioli, C.; Chalmet, P. L.; Chanlek, N.; Collu, A.; Giubilato, P.; Hillemanns, H.; Junique, A.; Keil, M.; Kim, D.; Kim, J.; Kugathasan, T.; Lattuca, A.; Mager, M.; Marin Tobon, C. A.; Marras, D.; Martinengo, P.; Mattiazzo, S.; Mazza, G.; Mugnier, H.; Musa, L.; Pantano, D.; Puggioni, C.; Rousset, J.; Reidt, F.; Riedler, P.; Siddhanta, S.; Snoeys, W.; Usai, G.; van Hoorne, J. W.; Yang, P.; Yi, J.

    2013-12-01

    ALICE plans an upgrade of its Inner Tracking System for 2018. The development of a monolithic active pixel sensor for this upgrade is described. The TowerJazz 180 nm CMOS imaging sensor process has been chosen as it is possible to use full CMOS in the pixel due to the offering of a deep pwell and also to use different starting materials. The ALPIDE development is an alternative to approaches based on a rolling shutter architecture, and aims to reduce power consumption and integration time by an order of magnitude below the ALICE specifications, which would be quite beneficial in terms of material budget and background. The approach is based on an in-pixel binary front-end combined with a hit-driven architecture. Several prototypes have already been designed, submitted for fabrication and some of them tested with X-ray sources and particles in a beam. Analog power consumption has been limited by optimizing the Q/C of the sensor using Explorer chips. Promising but preliminary first results have also been obtained with a prototype ALPIDE. Radiation tolerance up to the ALICE requirements has also been verified.

  10. Monolithic active pixel sensor development for the upgrade of the ALICE inner tracking system

    International Nuclear Information System (INIS)

    Aglieri, G; Cavicchioli, C; Hillemanns, H; Junique, A; Keil, M; Kugathasan, T; Mager, M; Tobon, C A Marin; Martinengo, P; Chalmet, P L; Mugnier, H; Chanlek, N; Collu, A; Marras, D; Giubilato, P; Mattiazzo, S; Kim, D; Kim, J; Lattuca, A; Mazza, G

    2013-01-01

    ALICE plans an upgrade of its Inner Tracking System for 2018. The development of a monolithic active pixel sensor for this upgrade is described. The TowerJazz 180 nm CMOS imaging sensor process has been chosen as it is possible to use full CMOS in the pixel due to the offering of a deep pwell and also to use different starting materials. The ALPIDE development is an alternative to approaches based on a rolling shutter architecture, and aims to reduce power consumption and integration time by an order of magnitude below the ALICE specifications, which would be quite beneficial in terms of material budget and background. The approach is based on an in-pixel binary front-end combined with a hit-driven architecture. Several prototypes have already been designed, submitted for fabrication and some of them tested with X-ray sources and particles in a beam. Analog power consumption has been limited by optimizing the Q/C of the sensor using Explorer chips. Promising but preliminary first results have also been obtained with a prototype ALPIDE. Radiation tolerance up to the ALICE requirements has also been verified

  11. CHARACTERIZATION OF A THIN SILICON SENSOR FOR ACTIVE NEUTRON PERSONAL DOSEMETERS.

    Science.gov (United States)

    Takada, M; Nunomiya, T; Nakamura, T; Matsumoto, T; Masuda, A

    2016-09-01

    A thin silicon sensor has been developed for active neutron personal dosemeters for use by aircrews and first responders. This thin silicon sensor is not affected by the funneling effect, which causes detection of cosmic protons and over-response to cosmic neutrons. There are several advantages to the thin silicon sensor: a decrease in sensitivity to gamma rays, an improvement of the energy detection limit for neutrons down to 0.8 MeV and an increase in the sensitivity to fast neutrons. Neutron response functions were experimentally obtained using 2.5 and 5 MeV monoenergy neutron beams and a (252)Cf neutron source. Simulation results using the Monte Carlo N-Particle transport code agree quite well with the experimental ones when an energy deposition region shaped like a circular truncated cone is used in place of a cylindrical region. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Development of a new catalase activity assay for biological samples using optical CUPRAC sensor.

    Science.gov (United States)

    Bekdeşer, Burcu; Özyürek, Mustafa; Güçlü, Kubilay; Alkan, Fulya Üstün; Apak, Reşat

    2014-11-11

    A novel catalase activity assay was developed for biological samples (liver and kidney tissue homogenates) using a rapid and low-cost optical sensor-based 'cupric reducing antioxidant capacity' (CUPRAC) method. The reagent, copper(II)-neocuproine (Cu(II)-Nc) complex, was immobilized onto a cation-exchanger film of Nafion, and the absorbance changes associated with the formation of the highly-colored Cu(I)-Nc chelate as a result of reaction with hydrogen peroxide (H2O2) was measured at 450 nm. When catalase was absent, H2O2 produced the CUPRAC chromophore, whereas catalase, being an effective H2O2 scavenger, completely annihilated the CUPRAC signal due to H2O2. Thus, the CUPRAC absorbance due to H2O2 oxidation concomitant with Cu(I)-Nc formation decreased proportionally with catalase. The developed sensor gave a linear response over a wide concentration range of H2O2 (0.68-78.6 μM). This optical sensor-based method applicable to tissue homogenates proved to be efficient for low hydrogen peroxide concentrations (physiological and nontoxic levels) to which the widely used UV method is not accurately responsive. Thus, conventional problems of the UV method arising from relatively low sensitivity and selectivity, and absorbance disturbance due to gaseous oxygen evolution were overcome. The catalase findings of the proposed method for tissue homogenates were statistically alike with those of HPLC. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Electrospun conducting polymer nanofibers as the active material in sensors and diodes

    International Nuclear Information System (INIS)

    Pinto, Nicholas J

    2013-01-01

    Polyaniline doped with camphorsulfonic acid (PANi-HCSA) and poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonic acid (PEDOT-PSSA) were electrospun separately to obtain individual nanofibers which were captured on Si/SiO 2 substrates and electrically characterized. The fiber resistance was recorded as a function of time in the presence of vapours of aliphatic alcohols of varying sizes. Due to the large surface to volume ratio, uniform diameter and small quantity of active material used in the construction, these sensor responses are very quick. Sensors made from individual fibers also show true saturation upon exposure to and removal of the sensing gas. A Schottky diode was also fabricated using an n-doped Si/SiO 2 substrate and a single PANi-HCSA fiber and tested in vacuum and in ammonia gas. The diode response was instantaneous upon exposure to ammonia with nearly complete recovery of the current upon pumping out the ammonia, thereby making it a reusable sensor with rectifying behaviour i.e. multifunctional.

  14. Towards real-time VMAT verification using a prototype, high-speed CMOS active pixel sensor.

    Science.gov (United States)

    Zin, Hafiz M; Harris, Emma J; Osmond, John P F; Allinson, Nigel M; Evans, Philip M

    2013-05-21

    This work investigates the feasibility of using a prototype complementary metal oxide semiconductor active pixel sensor (CMOS APS) for real-time verification of volumetric modulated arc therapy (VMAT) treatment. The prototype CMOS APS used region of interest read out on the chip to allow fast imaging of up to 403.6 frames per second (f/s). The sensor was made larger (5.4 cm × 5.4 cm) using recent advances in photolithographic technique but retains fast imaging speed with the sensor's regional read out. There is a paradigm shift in radiotherapy treatment verification with the advent of advanced treatment techniques such as VMAT. This work has demonstrated that the APS can track multi leaf collimator (MLC) leaves moving at 18 mm s(-1) with an automatic edge tracking algorithm at accuracy better than 1.0 mm even at the fastest imaging speed. Evaluation of the measured fluence distribution for an example VMAT delivery sampled at 50.4 f/s was shown to agree well with the planned fluence distribution, with an average gamma pass rate of 96% at 3%/3 mm. The MLC leaves motion and linac pulse rate variation delivered throughout the VMAT treatment can also be measured. The results demonstrate the potential of CMOS APS technology as a real-time radiotherapy dosimeter for delivery of complex treatments such as VMAT.

  15. Multi trace element analysis of dry biological materials by neutron activation analysis including a chemical group separation

    International Nuclear Information System (INIS)

    Weers, C.A.

    1980-07-01

    Multi-element analysis of dry biological material by neutron activation analysis has to include radiochemical separation. The evaporation process is described in terms of the half-volume. The pretreatment of the samples and the development of the destruction-evaporation apparatus are described. The successive adsorption steps with active charcoal, Al 2 O 3 and coprecipitation with Fe(OH) 3 are described. Results obtained for standard reference materials are summarized. (G.T.H.)

  16. Integrated X-ray and charged particle active pixel CMOS sensor arrays using an epitaxial silicon sensitive region

    International Nuclear Information System (INIS)

    Kleinfelder, Stuart; Bichsel, Hans; Bieser, Fred; Matis, Howard S.; Rai, Gulshan; Retiere, Fabrice; Weiman, Howard; Yamamoto, Eugene

    2002-01-01

    Integrated CMOS Active Pixel Sensor (APS) arrays have been fabricated and tested using X-ray and electron sources. The 128 by 128 pixel arrays, designed in a standard 0.25 micron process, use a ∼10 micron epitaxial silicon layer as a deep detection region. The epitaxial layer has a much greater thickness than the surface features used by standard CMOS APS, leading to stronger signals and potentially better signal-to-noise ratio (SNR). On the other hand, minority carriers confined within the epitaxial region may diffuse to neighboring pixels, blur images and reduce peak signal intensity. But for low-rate, sparse-event images, centroid analysis of this diffusion may be used to increase position resolution. Careful trade-offs involving pixel size and sense-node area verses capacitance must be made to optimize overall performance. The prototype sensor arrays, therefore, include a range of different pixel designs, including different APS circuits and a range of different epitaxial layer contact structures. The fabricated arrays were tested with 1.5 GeV electrons and Fe-55 X-ray sources, yielding a measured noise of 13 electrons RMS and an SNR for single Fe-55 X-rays of greater than 38

  17. Wearable Sensor-Based Human Activity Recognition Method with Multi-Features Extracted from Hilbert-Huang Transform.

    Science.gov (United States)

    Xu, Huile; Liu, Jinyi; Hu, Haibo; Zhang, Yi

    2016-12-02

    Wearable sensors-based human activity recognition introduces many useful applications and services in health care, rehabilitation training, elderly monitoring and many other areas of human interaction. Existing works in this field mainly focus on recognizing activities by using traditional features extracted from Fourier transform (FT) or wavelet transform (WT). However, these signal processing approaches are suitable for a linear signal but not for a nonlinear signal. In this paper, we investigate the characteristics of the Hilbert-Huang transform (HHT) for dealing with activity data with properties such as nonlinearity and non-stationarity. A multi-features extraction method based on HHT is then proposed to improve the effect of activity recognition. The extracted multi-features include instantaneous amplitude (IA) and instantaneous frequency (IF) by means of empirical mode decomposition (EMD), as well as instantaneous energy density (IE) and marginal spectrum (MS) derived from Hilbert spectral analysis. Experimental studies are performed to verify the proposed approach by using the PAMAP2 dataset from the University of California, Irvine for wearable sensors-based activity recognition. Moreover, the effect of combining multi-features vs. a single-feature are investigated and discussed in the scenario of a dependent subject. The experimental results show that multi-features combination can further improve the performance measures. Finally, we test the effect of multi-features combination in the scenario of an independent subject. Our experimental results show that we achieve four performance indexes: recall, precision, F-measure, and accuracy to 0.9337, 0.9417, 0.9353, and 0.9377 respectively, which are all better than the achievements of related works.

  18. Wearable Sensor-Based Human Activity Recognition Method with Multi-Features Extracted from Hilbert-Huang Transform

    Directory of Open Access Journals (Sweden)

    Huile Xu

    2016-12-01

    Full Text Available Wearable sensors-based human activity recognition introduces many useful applications and services in health care, rehabilitation training, elderly monitoring and many other areas of human interaction. Existing works in this field mainly focus on recognizing activities by using traditional features extracted from Fourier transform (FT or wavelet transform (WT. However, these signal processing approaches are suitable for a linear signal but not for a nonlinear signal. In this paper, we investigate the characteristics of the Hilbert-Huang transform (HHT for dealing with activity data with properties such as nonlinearity and non-stationarity. A multi-features extraction method based on HHT is then proposed to improve the effect of activity recognition. The extracted multi-features include instantaneous amplitude (IA and instantaneous frequency (IF by means of empirical mode decomposition (EMD, as well as instantaneous energy density (IE and marginal spectrum (MS derived from Hilbert spectral analysis. Experimental studies are performed to verify the proposed approach by using the PAMAP2 dataset from the University of California, Irvine for wearable sensors-based activity recognition. Moreover, the effect of combining multi-features vs. a single-feature are investigated and discussed in the scenario of a dependent subject. The experimental results show that multi-features combination can further improve the performance measures. Finally, we test the effect of multi-features combination in the scenario of an independent subject. Our experimental results show that we achieve four performance indexes: recall, precision, F-measure, and accuracy to 0.9337, 0.9417, 0.9353, and 0.9377 respectively, which are all better than the achievements of related works.

  19. Gas Sensor

    KAUST Repository

    Luebke, Ryan

    2015-01-22

    A gas sensor using a metal organic framework material can be fully integrated with related circuitry on a single substrate. In an on-chip application, the gas sensor can result in an area-efficient fully integrated gas sensor solution. In one aspect, a gas sensor can include a first gas sensing region including a first pair of electrodes, and a first gas sensitive material proximate to the first pair of electrodes, wherein the first gas sensitive material includes a first metal organic framework material.

  20. Gas Sensor

    KAUST Repository

    Luebke, Ryan; Eddaoudi, Mohamed; Omran, Hesham; Belmabkhout, Youssef; Shekhah, Osama; Salama, Khaled N.

    2015-01-01

    A gas sensor using a metal organic framework material can be fully integrated with related circuitry on a single substrate. In an on-chip application, the gas sensor can result in an area-efficient fully integrated gas sensor solution. In one aspect, a gas sensor can include a first gas sensing region including a first pair of electrodes, and a first gas sensitive material proximate to the first pair of electrodes, wherein the first gas sensitive material includes a first metal organic framework material.

  1. Ultrasensitive surveillance of sensors and processes

    International Nuclear Information System (INIS)

    Wegerich, S.W.; Jarman, K.K.; Gross, K.C.

    1999-01-01

    A method and apparatus for monitoring a source of data for determining an operating state of a working system are disclosed. The method includes determining a sensor (or source of data) arrangement associated with monitoring the source of data for a system, activating a method for performing a sequential probability ratio test if the data source includes a single data (sensor) source, activating a second method for performing a regression sequential possibility ratio testing procedure if the arrangement includes a pair of sensors (data sources) with signals which are linearly or non-linearly related; activating a third method for performing a bounded angle ratio test procedure if the sensor arrangement includes multiple sensors and utilizing at least one of the first, second and third methods to accumulate sensor signals and determining the operating state of the system

  2. Low-cost sensor integrators for measuring the transmissivity of complex canopies to photosynthetically active radiation

    International Nuclear Information System (INIS)

    Newman, S.M.

    1985-01-01

    A system has been designed, tested and evaluated for measuring the transmissivities of complex canopies to photosynthetically active radiation (PAR). The system consists of filtered silicon photocells in cosine corrected mounts with outputs integrated by the use of chemical coulometers. The reading accumulated by the coulometers was taken electronically by the use of microcomputers. The low-cost sensor integrators, which do not require batteries, performed as expected and proved ideal for the study of agroforestry systems in remote areas. Information on the PAR transmissivity of a temperate agroforestry system in the form of an intercropped orchard is also presented. (author)

  3. Study of prototypes of LFoundry active CMOS pixels sensors for the ATLAS detector

    Science.gov (United States)

    Vigani, L.; Bortoletto, D.; Ambroz, L.; Plackett, R.; Hemperek, T.; Rymaszewski, P.; Wang, T.; Krueger, H.; Hirono, T.; Caicedo Sierra, I.; Wermes, N.; Barbero, M.; Bhat, S.; Breugnon, P.; Chen, Z.; Godiot, S.; Pangaud, P.; Rozanov, A.

    2018-02-01

    Current high energy particle physics experiments at the LHC use hybrid silicon detectors, in both pixel and strip configurations, for their inner trackers. These detectors have proven to be very reliable and performant. Nevertheless, there is great interest in depleted CMOS silicon detectors, which could achieve a similar performance at lower cost of production. We present recent developments of this technology in the framework of the ATLAS CMOS demonstrator project. In particular, studies of two active sensors from LFoundry, CCPD_LF and LFCPIX, are shown.

  4. Study of prototypes of LFoundry active CMOS pixels sensors for the ATLAS detector

    CERN Document Server

    Vigani, L.; Ambroz, L.; Plackett, R.; Hemperek, T.; Rymaszewski, P.; Wang, T.; Krueger, H.; Hirono, T.; Caicedo Sierra, I.; Wermes, N.; Barbero, M.; Bhat, S.; Breugnon, P.; Chen, Z.; Godiot, S.; Pangaud, P.; Rozanov, A.

    2018-01-01

    Current high energy particle physics experiments at the LHC use hybrid silicon detectors, in both pixel and strip configurations, for their inner trackers. These detectors have proven to be very reliable and performant. Nevertheless, there is great interest in depleted CMOS silicon detectors, which could achieve a similar performance at lower cost of production. We present recent developments of this technology in the framework of the ATLAS CMOS demonstrator project. In particular, studies of two active sensors from LFoundry, CCPD_LF and LFCPIX, are shown.

  5. Analysis of 3D stacked fully functional CMOS Active Pixel Sensor detectors

    International Nuclear Information System (INIS)

    Passeri, D; Servoli, L; Meroli, S

    2009-01-01

    The IC technology trend is to move from 3D flexible configurations (package on package, stacked dies) to real 3D ICs. This is mainly due to i) the increased electrical performances and ii) the cost of 3D integration which may be cheaper than to keep shrinking 2D circuits. Perspective advantages for particle tracking and vertex detectors applications in High Energy Physics can be envisaged: in this work, we will focus on the capabilities of the state-of-the-art vertical scale integration technologies, allowing for the fabrication of very compact, fully functional, multiple layers CMOS Active Pixel Sensor (APS) detectors. The main idea is to exploit the features of the 3D technologies for the fabrication of a ''stack'' of very thin and precisely aligned CMOS APS layers, leading to a single, integrated, multi-layers pixel sensor. The adoption of multiple-layers single detectors can dramatically reduce the mass of conventional, separated detectors (thus reducing multiple scattering issues), at the same time allowing for very precise measurements of particle trajectory and momentum. As a proof of concept, an extensive device and circuit simulation activity has been carried out, aiming at evaluate the suitability of such a kind of CMOS active pixel layers for particle tracking purposes.

  6. Dense range map reconstruction from a versatile robotic sensor system with an active trinocular vision and a passive binocular vision.

    Science.gov (United States)

    Kim, Min Young; Lee, Hyunkee; Cho, Hyungsuck

    2008-04-10

    One major research issue associated with 3D perception by robotic systems is the creation of efficient sensor systems that can generate dense range maps reliably. A visual sensor system for robotic applications is developed that is inherently equipped with two types of sensor, an active trinocular vision and a passive stereo vision. Unlike in conventional active vision systems that use a large number of images with variations of projected patterns for dense range map acquisition or from conventional passive vision systems that work well on specific environments with sufficient feature information, a cooperative bidirectional sensor fusion method for this visual sensor system enables us to acquire a reliable dense range map using active and passive information simultaneously. The fusion algorithms are composed of two parts, one in which the passive stereo vision helps active vision and the other in which the active trinocular vision helps the passive one. The first part matches the laser patterns in stereo laser images with the help of intensity images; the second part utilizes an information fusion technique using the dynamic programming method in which image regions between laser patterns are matched pixel-by-pixel with help of the fusion results obtained in the first part. To determine how the proposed sensor system and fusion algorithms can work in real applications, the sensor system is implemented on a robotic system, and the proposed algorithms are applied. A series of experimental tests is performed for a variety of configurations of robot and environments. The performance of the sensor system is discussed in detail.

  7. Effects of Leisure Education Programme Including Sportive Activities on Perceived Freedom in Leisure of Adolescents with Intellectual Disabilities

    Science.gov (United States)

    Ertuzun, Ezgi

    2015-01-01

    The objective of this experimental study is to determine the effect of leisure education programme including sportive activities on the perceived freedom in leisure of adolescents with mild intellectual disabilities. The research was designed with an experimental group (n = 37) and a control group (n = 34), and was conducted among a total of 71…

  8. The FARE: A new way to express FAlls Risk among older persons including physical activity as a measure of Exposure

    NARCIS (Netherlands)

    Wijlhuizen, G.J.; Chorus, A.M.J.; Hopman-Rock, M.

    2010-01-01

    Background: Common expressions of falls risk do not include exposure to hazards. We compared two expressions: the commonly used population incidence (fallers per 1000 person-years) and the FARE (FAlls Risk by Exposure): the number of fallers per 1000 physically active person-days. Methods:

  9. The FARE: a new way to express FAlls Risk among older persons including physical activity as a measure of exposure

    NARCIS (Netherlands)

    Wijlhuizen, G.J.; Chorus, A.M.J.; Hopman-Rock, M.

    2010-01-01

    Background: Common expressions of falls risk do not include exposure to hazards. We compared two expressions: the commonly used population incidence (fallers per 1000 person-years) and the FARE (FAlls Risk by Exposure): the number of fallers per 1000 physically active person-days. Methods:

  10. The association between school-based physical activity, including physical education, and academic performance: a systematic review of the literature.

    Science.gov (United States)

    Rasberry, Catherine N; Lee, Sarah M; Robin, Leah; Laris, B A; Russell, Lisa A; Coyle, Karin K; Nihiser, Allison J

    2011-06-01

    The purpose of this review is to synthesize the scientific literature that has examined the association between school-based physical activity (including physical education) and academic performance (including indicators of cognitive skills and attitudes, academic behaviors, and academic achievement). Relevant research was identified through a search of nine electronic databases using both physical activity and academic-related search terms. Forty-three articles (reporting a total of 50 unique studies) met the inclusion criteria and were read, abstracted, and coded for this synthesis. Findings of the 50 studies were then summarized. Across all the studies, there were a total of 251 associations between physical activity and academic performance, representing measures of academic achievement, academic behavior, and cognitive skills and attitudes. Slightly more than half (50.5%) of all associations examined were positive, 48% were not significant, and 1.5% were negative. Examination of the findings by each physical activity context provides insights regarding specific relationships. Results suggest physical activity is either positively related to academic performance or that there is not a demonstrated relationship between physical activity and academic performance. Results have important implications for both policy and schools. Copyright © 2010 Elsevier Inc. All rights reserved.

  11. Analysis of test beam data of ALPIDE, the Monolithic Active Pixel Sensor (MAPS) for the ALICE ITS upgrade

    CERN Document Server

    Lazareva, Tatiana

    2017-01-01

    The ALICE experiment has scheduled a major upgrade of its experimen- tal apparatus for the Long Shutdown 2 of LHC in 2019-2020. Within this enterprise, CERN is strongly involved in the development of a novel Inner Tracking System (ITS). The ITS will be based on Monolithic Active Pixel Sensors (MAPS), a cutting-edge technology that will allow to improve the detector performance signicantly. The nal sensor, called ALPIDE, is in production since December 2016. This project is focused on the characterization of irradiated ALPIDE sensors.

  12. X-ray metrology of an array of active edge pixel sensors for use at synchrotron light sources

    Science.gov (United States)

    Plackett, R.; Arndt, K.; Bortoletto, D.; Horswell, I.; Lockwood, G.; Shipsey, I.; Tartoni, N.; Williams, S.

    2018-01-01

    We report on the production and testing of an array of active edge silicon sensors as a prototype of a large array. Four Medipix3RX.1 chips were bump bonded to four single chip sized Advacam active edge n-on-n sensors. These detectors were then mounted into a 2 by 2 array and tested on B16 at Diamond Light Source with an x-ray beam spot of 2um. The results from these tests, compared with optical metrology demonstrate that this type of sensor is sensitive to the physical edge of the silicon, with only a modest loss of efficiency in the final two rows of pixels. We present the efficiency maps recorded with the microfocus beam and a sample powder diffraction measurement. These results give confidence that this sensor technology can be used effectively in larger arrays of detectors at synchrotron light sources.

  13. A Low-Operating-Power and Flexible Active-Matrix Organic-Transistor Temperature-Sensor Array.

    Science.gov (United States)

    Ren, Xiaochen; Pei, Ke; Peng, Boyu; Zhang, Zhichao; Wang, Zongrong; Wang, Xinyu; Chan, Paddy K L

    2016-06-01

    An organic flexible temperature-sensor array exhibits great potential in health monitoring and other biomedical applications. The actively addressed 16 × 16 temperature sensor array reaches 100% yield rate and provides 2D temperature information of the objects placed in contact, even if the object has an irregular shape. The current device allows defect predictions of electronic devices, remote sensing of harsh environments, and e-skin applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Mouse preimplantation embryo responses to culture medium osmolarity include increased expression of CCM2 and p38 MAPK activation

    Directory of Open Access Journals (Sweden)

    Watson Andrew J

    2007-01-01

    Full Text Available Abstract Background Mechanisms that confer an ability to respond positively to environmental osmolarity are fundamental to ensuring embryo survival during the preimplantation period. Activation of p38 mitogen-activated protein kinase (MAPK occurs following exposure to hyperosmotic treatment. Recently, a novel scaffolding protein called Osmosensing Scaffold for MEKK3 (OSM was linked to p38 MAPK activation in response to sorbitol-induced hypertonicity. The human ortholog of OSM is cerebral cavernous malformation 2 (CCM2. The present study was conducted to investigate whether CCM2 is expressed during mouse preimplantation development and to determine whether this scaffolding protein is associated with p38 MAPK activation following exposure of preimplantation embryos to hyperosmotic environments. Results Our results indicate that Ccm2 along with upstream p38 MAPK pathway constituents (Map3k3, Map2k3, Map2k6, and Map2k4 are expressed throughout mouse preimplantation development. CCM2, MAP3K3 and the phosphorylated forms of MAP2K3/MAP2K6 and MAP2K4 were also detected throughout preimplantation development. Embryo culture in hyperosmotic media increased p38 MAPK activity in conjunction with elevated CCM2 levels. Conclusion These results define the expression of upstream activators of p38 MAPK during preimplantation development and indicate that embryo responses to hyperosmotic environments include elevation of CCM2 and activation of p38 MAPK.

  15. Shear horizontal wave excitation and reception with shear horizontal piezoelectric wafer active sensor (SH-PWAS)

    International Nuclear Information System (INIS)

    Kamal, A; Giurgiutiu, V

    2014-01-01

    This article discusses shear horizontal (SH) guided-waves that can be excited with shear type piezoelectric wafer active sensor (SH-PWAS). The paper starts with a review of state of the art SH waves modelling and their importance in non-destructive evaluation (NDE) and structural health monitoring (SHM). The basic piezoelectric sensing and actuation equations for the case of shear horizontal piezoelectric wafer active sensor (SH-PWAS) with electro-mechanical coupling coefficient d 35 are reviewed. Multiphysics finite element modelling (MP-FEM) was performed on a free SH-PWAS to show its resonance modeshapes. The actuation mechanism of the SH-PWAS is predicted by MP-FEM, and modeshapes of excited structure are presented. The structural resonances are compared with experimental measurements and showed good agreement. Analytical prediction of SH waves was performed. SH wave propagation experimental study was conducted between different combinations of SH-PWAS and regular in-plane PWAS transducers. Experimental results were compared with analytical predictions for aluminium plates and showed good agreement. 2D wave propagation effects were studied by MP-FEM. An analytical model was developed for SH wave power and energy. The normal mode expansion (NME) method was used to account for superpositioning multimodal SH waves. Modal participation factors were presented to show the contribution of every mode. Power and energy transfer between SH-PWAS and the structure was analyzed. Finally, we present simulations of our developed wave power and energy analytical models. (paper)

  16. Activity-Dependent IGF-1 Exocytosis is Controlled by the Ca2+-Sensor Synaptotagmin-10

    Science.gov (United States)

    Cao, Peng; Maximov, Anton; Südhof, Thomas C.

    2011-01-01

    Synaptotagmins Syt1, Syt2, Syt7, and Syt9 act as Ca2+-sensors for synaptic and neuroendocrine exocytosis, but the function of other synaptotagmins remains unknown. Here, we show that olfactory bulb neurons secrete IGF-1 by an activity-dependent pathway of exocytosis, and that Syt10 functions as the Ca2+-sensor that triggers IGF-1 exocytosis in these neurons. Deletion of Syt10 impaired activity-dependent IGF-1 secretion in olfactory bulb neurons, resulting in smaller neurons and an overall decrease in synapse numbers. Exogenous IGF-1 completely reversed the Syt10 knockout phenotype. Syt10 co-localized with IGF-1 in somatodendritic vesicles of olfactory bulb neurons, and Ca2+-binding to Syt10 caused these vesicles to undergo exocytosis, thereby secreting IGF-1. Thus, Syt10 controls a previously unrecognized pathway of Ca2+-dependent exocytosis that is spatially and temporally distinct from Ca2+-dependent synaptic vesicle exocytosis controlled by Syt1 in the same neurons, and two different synaptotagmins regulate distinct Ca2+-dependent membrane fusion reactions during exocytosis in the same neuron. PMID:21496647

  17. Convolutional Neural Networks for Human Activity Recognition Using Body-Worn Sensors

    Directory of Open Access Journals (Sweden)

    Fernando Moya Rueda

    2018-05-01

    Full Text Available Human activity recognition (HAR is a classification task for recognizing human movements. Methods of HAR are of great interest as they have become tools for measuring occurrences and durations of human actions, which are the basis of smart assistive technologies and manual processes analysis. Recently, deep neural networks have been deployed for HAR in the context of activities of daily living using multichannel time-series. These time-series are acquired from body-worn devices, which are composed of different types of sensors. The deep architectures process these measurements for finding basic and complex features in human corporal movements, and for classifying them into a set of human actions. As the devices are worn at different parts of the human body, we propose a novel deep neural network for HAR. This network handles sequence measurements from different body-worn devices separately. An evaluation of the architecture is performed on three datasets, the Oportunity, Pamap2, and an industrial dataset, outperforming the state-of-the-art. In addition, different network configurations will also be evaluated. We find that applying convolutions per sensor channel and per body-worn device improves the capabilities of convolutional neural network (CNNs.

  18. Accuracy of a novel multi-sensor board for measuring physical activity and energy expenditure.

    Science.gov (United States)

    Duncan, Glen E; Lester, Jonathan; Migotsky, Sean; Goh, Jorming; Higgins, Lisa; Borriello, Gaetano

    2011-09-01

    The ability to relate physical activity to health depends on accurate measurement. Yet, none of the available methods are fully satisfactory due to several factors. This study examined the accuracy of a multi-sensor board (MSB) that infers activity types (sitting, standing, walking, stair climbing, and running) and estimates energy expenditure in 57 adults (32 females) 39.2 ± 13.5 years. In the laboratory, subjects walked and ran on a treadmill over a select range of speeds and grades for 3 min each (six stages in random order) while connected to a stationary calorimeter, preceded and followed by brief sitting and standing. On a different day, subjects completed scripted activities in the field connected to a portable calorimeter. The MSB was attached to a strap at the right hip. Subjects repeated one condition (randomly selected) on the third day. Accuracy of inferred activities compared with recorded activities (correctly identified activities/total activities × 100) was 97 and 84% in the laboratory and field, respectively. Absolute accuracy of energy expenditure [100 - absolute value (kilocalories MSB - kilocalories calorimeter/kilocalories calorimeter) × 100] was 89 and 76% in the laboratory and field, the later being different (P calorimeter. Test-retest reliability for energy expenditure was significant in both settings (P type in laboratory and field settings and energy expenditure during treadmill walking and running although the device underestimates energy expenditure in the field.

  19. Sensors, Volume 4, Thermal Sensors

    Science.gov (United States)

    Scholz, Jorg; Ricolfi, Teresio

    1996-12-01

    'Sensors' is the first self-contained series to deal with the whole area of sensors. It describes general aspects, technical and physical fundamentals, construction, function, applications and developments of the various types of sensors. This volume describes the construction and applicational aspects of thermal sensors while presenting a rigorous treatment of the underlying physical principles. It provides a unique overview of the various categories of sensors as well as of specific groups, e.g. temperature sensors (resistance thermometers, thermocouples, and radiation thermometers), noise and acoustic thermometers, heat-flow and mass-flow sensors. Specific facettes of applications are presented by specialists from different fields including process control, automotive technology and cryogenics. This volume is an indispensable reference work and text book for both specialists and newcomers, researchers and developers.

  20. Active/passive microwave sensor comparison of MIZ-ice concentration estimates. [Marginal Ice Zone (MIZ)

    Science.gov (United States)

    Burns, B. A.; Cavalieri, D. J.; Keller, M. R.

    1986-01-01

    Active and passive microwave data collected during the 1984 summer Marginal Ice Zone Experiment in the Fram Strait (MIZEX 84) are used to compare ice concentration estimates derived from synthetic aperture radar (SAR) data to those obtained from passive microwave imagery at several frequencies. The comparison is carried out to evaluate SAR performance against the more established passive microwave technique, and to investigate discrepancies in terms of how ice surface conditions, imaging geometry, and choice of algorithm parameters affect each sensor. Active and passive estimates of ice concentration agree on average to within 12%. Estimates from the multichannel passive microwave data show best agreement with the SAR estimates because the multichannel algorithm effectively accounts for the range in ice floe brightness temperatures observed in the MIZ.

  1. Heavy Ion Transient Characterization of a Photobit Hardened-by-Design Active Pixel Sensor Array

    Science.gov (United States)

    Marshall, Paul W.; Byers, Wheaton B.; Conger, Christopher; Eid, El-Sayed; Gee, George; Jones, Michael R.; Marshall, Cheryl J.; Reed, Robert; Pickel, Jim; Kniffin, Scott

    2002-01-01

    This paper presents heavy ion data on the single event transient (SET) response of a Photobit active pixel sensor (APS) four quadrant test chip with different radiation tolerant designs in a standard 0.35 micron CMOS process. The physical design techniques of enclosed geometry and P-channel guard rings are used to design the four N-type active photodiode pixels as described in a previous paper. Argon transient measurements on the 256 x 256 chip array as a function of incident angle show a significant variation in the amount of charge collected as well as the charge spreading dependent on the pixel type. The results are correlated with processing and design information provided by Photobit. In addition, there is a large degree of statistical variability between individual ion strikes. No latch-up is observed up to an LET of 106 MeV/mg/sq cm.

  2. Wide dynamic logarithmic InGaAs sensor suitable for eye-safe active imaging

    Science.gov (United States)

    Ni, Yang; Bouvier, Christian; Arion, Bogdan; Noguier, Vincent

    2016-05-01

    In this paper, we present a simple method to analyze the injection efficiency of the photodiode interface circuit under fast shuttering conditions for active Imaging applications. This simple model has been inspired from the companion model for reactive elements largely used in CAD. In this paper, we demonstrate that traditional CTIA photodiode interface is not adequate for active imaging where fast and precise shuttering operation is necessary. Afterwards we present a direct amplification based photodiode interface which can provide an accurate and fast shuttering operation on photodiode. These considerations have been used in NIT's newly developed ROIC and corresponding SWIR sensors both in VGA 15um pitch (NSC1201) and also in QVGA 25um pitch (NSC1401).

  3. Comportamento do NDVI obtido por sensor ótico ativo em cereais Behavior of NDVI obtained from an active optical sensor in cereals

    Directory of Open Access Journals (Sweden)

    Fabrício Pinheiro Povh

    2008-08-01

    Full Text Available O objetivo deste trabalho foi avaliar, com um sensor ótico ativo, o comportamento do índice de vegetação por diferença normalizada (NDVI - "normalized difference vegetation index", nas culturas de trigo, triticale, cevada e milho. Cinco experimentos foram conduzidos no Paraná e São Paulo, com variação de classes de solo, doses e fontes de N, e variedades de trigo. As seguintes variáveis foram avaliadas: NDVI, teor de N foliar, matéria seca e produtividade das culturas. Análises de regressões foram realizadas entre as doses de N aplicadas e NDVI, teor de N foliar, matéria seca e produtividade. Análises de correlação entre as variáveis foram realizadas. O trigo, triticale e cevada apresentaram resposta às aplicações de doses crescentes de N, pelo aumento nas leituras do NDVI, no teor de N foliar e na produtividade. Medido pelo sensor ótico ativo utilizado, o NDVI apresenta alto potencial para manejo do N nas culturas do trigo, triticale e cevada, e baixo potencial para a cultura do milho. Há interferência das variedades de trigo nas leituras do sensor ótico ativo.The objective of this work was to evaluate the behavior of the normalized difference vegetation index (NDVI, with an active optical sensor, in wheat, triticale, barley and corn crops. Experiments were conducted in Paraná and São Paulo, comparing different soil classes, N rates and sources, and wheat varieties. The following variables were determined: NDVI, N foliar content, dry mass and crop yield. Regression analyses were performed between NDVI and applied N rates, N foliar content, dry mass and yield. Correlation analyses among the variables were performed. Wheat, triticale and barley crops showed response to increasing N rates by the increase in the NDVI readings, to N foliar content and to yield. Measured by the used active optical sensor the NDVI shows high potential for N management wheat, triticale and barley crops, and low potential for corn crops. There

  4. Development of a thinned back-illuminated CMOS active pixel sensor for extreme ultraviolet spectroscopy and imaging in space science

    International Nuclear Information System (INIS)

    Waltham, N.R.; Prydderch, M.; Mapson-Menard, H.; Pool, P.; Harris, A.

    2007-01-01

    We describe our programme to develop a large-format, science-grade, monolithic CMOS active pixel sensor for future space science missions, and in particular an extreme ultraviolet (EUV) spectrograph for solar physics studies on ESA's Solar Orbiter. Our route to EUV sensitivity relies on adapting the back-thinning and rear-illumination techniques first developed for CCD sensors. Our first large-format sensor consists of 4kx3k 5 μm pixels fabricated on a 0.25 μm CMOS imager process. Wafer samples of these sensors have been thinned by e2v technologies with the aim of obtaining good sensitivity at EUV wavelengths. We present results from both front- and back-illuminated versions of this sensor. We also present our plans to develop a new sensor of 2kx2k 10 μm pixels, which will be fabricated on a 0.35 μm CMOS process. In progress towards this goal, we have designed a test-structure consisting of six arrays of 512x512 10 μm pixels. Each of the arrays has been given a different pixel design to allow verification of our models, and our progress towards optimizing a design for minimal system readout noise and maximum dynamic range. These sensors will also be back-thinned for characterization at EUV wavelengths

  5. On the Use of Sensor Fusion to Reduce the Impact of Rotational and Additive Noise in Human Activity Recognition

    Directory of Open Access Journals (Sweden)

    Ignacio Rojas

    2012-06-01

    Full Text Available The main objective of fusion mechanisms is to increase the individual reliability of the systems through the use of the collectivity knowledge. Moreover, fusion models are also intended to guarantee a certain level of robustness. This is particularly required for problems such as human activity recognition where runtime changes in the sensor setup seriously disturb the reliability of the initial deployed systems. For commonly used recognition systems based on inertial sensors, these changes are primarily characterized as sensor rotations, displacements or faults related to the batteries or calibration. In this work we show the robustness capabilities of a sensor-weighted fusion model when dealing with such disturbances under different circumstances. Using the proposed method, up to 60% outperformance is obtained when a minority of the sensors are artificially rotated or degraded, independent of the level of disturbance (noise imposed. These robustness capabilities also apply for any number of sensors affected by a low to moderate noise level. The presented fusion mechanism compensates the poor performance that otherwise would be obtained when just a single sensor is considered.

  6. Comparison of Surface and Column Variations of CO2 Over Urban Areas for Future Active Remote CO2 Sensors

    Science.gov (United States)

    Choi, Yonghoon; Yang, Melissa; Kooi, Susan; Browell, Edward

    2015-01-01

    High resolution in-situ CO2 measurements were recorded onboard the NASA P-3B during the DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) Field Campaign, to investigate the ability of space-based observations to accurately assess near surface conditions related to air quality. This campaign includes, Washington DC/Baltimore, MD (July 2011), San Joaquin Valley, CA (January - February 2013), Houston, TX (September 2013), and Denver, CO (July-August 2014). Each of these campaigns consisted of missed approaches and approximately two hundred vertical soundings of CO2 within the lower troposphere (surface to about 5 km). In this study, surface (0 - 1 km) and column-averaged (0 - 3.5 km) CO2 mixing ratio values from the vertical soundings in the four geographically different urban areas are used to investigate the temporal and spatial variability of CO2 within the different urban atmospheric emission environments. Tracers such as CO, CH2O, NOx, and NMHCs are used to identify the source of CO2 variations in the urban sites. Additionally, we apply nominal CO2 column weighting functions for potential future active remote CO2 sensors operating in the 1.57-microns and 2.05-microns measurement regions to convert the in situ CO2 vertical mixing ratio profiles to variations in CO2 column optical depths, which is what the active remote sensors actually measure. Using statistics calculated from the optical depths at each urban site measured during the DISCOVER-AQ field campaign and for each nominal weighting function, we investigate the natural variability of CO2 columns in the lower troposphere; relate the CO2 column variability to the urban surface emissions; and show the measurement requirements for the future ASCENDS (Active Sensing of CO2 Emissions over Nights, Days, and Seasons) in the continental U.S. urban areas.

  7. Low-power priority Address-Encoder and Reset-Decoder data-driven readout for Monolithic Active Pixel Sensors for tracker system

    Science.gov (United States)

    Yang, P.; Aglieri, G.; Cavicchioli, C.; Chalmet, P. L.; Chanlek, N.; Collu, A.; Gao, C.; Hillemanns, H.; Junique, A.; Kofarago, M.; Keil, M.; Kugathasan, T.; Kim, D.; Kim, J.; Lattuca, A.; Marin Tobon, C. A.; Marras, D.; Mager, M.; Martinengo, P.; Mazza, G.; Mugnier, H.; Musa, L.; Puggioni, C.; Rousset, J.; Reidt, F.; Riedler, P.; Snoeys, W.; Siddhanta, S.; Usai, G.; van Hoorne, J. W.; Yi, J.

    2015-06-01

    Active Pixel Sensors used in High Energy Particle Physics require low power consumption to reduce the detector material budget, low integration time to reduce the possibilities of pile-up and fast readout to improve the detector data capability. To satisfy these requirements, a novel Address-Encoder and Reset-Decoder (AERD) asynchronous circuit for a fast readout of a pixel matrix has been developed. The AERD data-driven readout architecture operates the address encoding and reset decoding based on an arbitration tree, and allows us to readout only the hit pixels. Compared to the traditional readout structure of the rolling shutter scheme in Monolithic Active Pixel Sensors (MAPS), AERD can achieve a low readout time and a low power consumption especially for low hit occupancies. The readout is controlled at the chip periphery with a signal synchronous with the clock, allows a good digital and analogue signal separation in the matrix and a reduction of the power consumption. The AERD circuit has been implemented in the TowerJazz 180 nm CMOS Imaging Sensor (CIS) process with full complementary CMOS logic in the pixel. It works at 10 MHz with a matrix height of 15 mm. The energy consumed to read out one pixel is around 72 pJ. A scheme to boost the readout speed to 40 MHz is also discussed. The sensor chip equipped with AERD has been produced and characterised. Test results including electrical beam measurement are presented.

  8. Low-power priority Address-Encoder and Reset-Decoder data-driven readout for Monolithic Active Pixel Sensors for tracker system

    International Nuclear Information System (INIS)

    Yang, P.; Aglieri, G.; Cavicchioli, C.; Chalmet, P.L.; Chanlek, N.; Collu, A.; Gao, C.; Hillemanns, H.; Junique, A.; Kofarago, M.; Keil, M.; Kugathasan, T.; Kim, D.; Kim, J.; Lattuca, A.; Marin Tobon, C.A.; Marras, D.; Mager, M.; Martinengo, P.; Mazza, G.

    2015-01-01

    Active Pixel Sensors used in High Energy Particle Physics require low power consumption to reduce the detector material budget, low integration time to reduce the possibilities of pile-up and fast readout to improve the detector data capability. To satisfy these requirements, a novel Address-Encoder and Reset-Decoder (AERD) asynchronous circuit for a fast readout of a pixel matrix has been developed. The AERD data-driven readout architecture operates the address encoding and reset decoding based on an arbitration tree, and allows us to readout only the hit pixels. Compared to the traditional readout structure of the rolling shutter scheme in Monolithic Active Pixel Sensors (MAPS), AERD can achieve a low readout time and a low power consumption especially for low hit occupancies. The readout is controlled at the chip periphery with a signal synchronous with the clock, allows a good digital and analogue signal separation in the matrix and a reduction of the power consumption. The AERD circuit has been implemented in the TowerJazz 180 nm CMOS Imaging Sensor (CIS) process with full complementary CMOS logic in the pixel. It works at 10 MHz with a matrix height of 15 mm. The energy consumed to read out one pixel is around 72 pJ. A scheme to boost the readout speed to 40 MHz is also discussed. The sensor chip equipped with AERD has been produced and characterised. Test results including electrical beam measurement are presented

  9. Low-power priority Address-Encoder and Reset-Decoder data-driven readout for Monolithic Active Pixel Sensors for tracker system

    Energy Technology Data Exchange (ETDEWEB)

    Yang, P., E-mail: yangping0710@126.com [Central China Normal University, Wuhan (China); Aglieri, G.; Cavicchioli, C. [CERN, 1210 Geneva 23 (Switzerland); Chalmet, P.L. [MIND, Archamps (France); Chanlek, N. [Suranaree University of Technology, Nakhon Ratchasima (Thailand); Collu, A. [University of Cagliari, Cagliari (Italy); INFN (Italy); Gao, C. [Central China Normal University, Wuhan (China); Hillemanns, H.; Junique, A. [CERN, 1210 Geneva 23 (Switzerland); Kofarago, M. [CERN, 1210 Geneva 23 (Switzerland); University of Utrecht, Utrecht (Netherlands); Keil, M.; Kugathasan, T. [CERN, 1210 Geneva 23 (Switzerland); Kim, D. [Dongguk and Yonsei University, Seoul (Korea, Republic of); Kim, J. [Pusan National University, Busan (Korea, Republic of); Lattuca, A. [University of Torino, Torino (Italy); INFN (Italy); Marin Tobon, C.A. [CERN, 1210 Geneva 23 (Switzerland); Marras, D. [University of Cagliari, Cagliari (Italy); INFN (Italy); Mager, M.; Martinengo, P. [CERN, 1210 Geneva 23 (Switzerland); Mazza, G. [University of Torino, Torino (Italy); INFN (Italy); and others

    2015-06-11

    Active Pixel Sensors used in High Energy Particle Physics require low power consumption to reduce the detector material budget, low integration time to reduce the possibilities of pile-up and fast readout to improve the detector data capability. To satisfy these requirements, a novel Address-Encoder and Reset-Decoder (AERD) asynchronous circuit for a fast readout of a pixel matrix has been developed. The AERD data-driven readout architecture operates the address encoding and reset decoding based on an arbitration tree, and allows us to readout only the hit pixels. Compared to the traditional readout structure of the rolling shutter scheme in Monolithic Active Pixel Sensors (MAPS), AERD can achieve a low readout time and a low power consumption especially for low hit occupancies. The readout is controlled at the chip periphery with a signal synchronous with the clock, allows a good digital and analogue signal separation in the matrix and a reduction of the power consumption. The AERD circuit has been implemented in the TowerJazz 180 nm CMOS Imaging Sensor (CIS) process with full complementary CMOS logic in the pixel. It works at 10 MHz with a matrix height of 15 mm. The energy consumed to read out one pixel is around 72 pJ. A scheme to boost the readout speed to 40 MHz is also discussed. The sensor chip equipped with AERD has been produced and characterised. Test results including electrical beam measurement are presented.

  10. Lightning Imaging Sensor (LIS) on the International Space Station (ISS): Launch, Installation, Activation, and First Results

    Science.gov (United States)

    Blakeslee, R. J.; Christian, H. J., Jr.; Mach, D. M.; Buechler, D. E.; Koshak, W. J.; Walker, T. D.; Bateman, M. G.; Stewart, M. F.; O'Brien, S.; Wilson, T. O.; Pavelitz, S. D.; Coker, C.

    2016-12-01

    Over the past 20 years, the NASA Marshall Space Flight Center, the University of Alabama in Huntsville, and their partners developed and demonstrated the effectiveness and value of space-based lightning observations as a remote sensing tool for Earth science research and applications, and, in the process, established a robust global lightning climatology. The observations included measurements from the Lightning Imaging Sensor (LIS) on the Tropical Rainfall Measuring Mission (TRMM) and its Optical Transient Detector (OTD) predecessor that acquired global observations of total lightning (i.e., intracloud and cloud-to-ground discharges) spanning a period from May 1995 through April 2015. As an exciting follow-on to these prior missions, a space-qualified LIS built as a flight-spare for TRMM will be delivered to the International Space Station (ISS) for a 2 year or longer mission, flown as a hosted payload on the Department of Defense (DoD) Space Test Program-Houston 5 (STP-H5) mission. The STP-H5 payload containing LIS is scheduled launch from NASA's Kennedy Space Center to the ISS in November 2016, aboard the SpaceX Cargo Resupply Services-10 (SpaceX-10) mission, installed in the unpressurized "trunk" of the Dragon spacecraft. After the Dragon is berth to ISS Node 2, the payload will be removed from the trunk and robotically installed in a nadir-viewing location on the external truss of the ISS. Following installation on the ISS, the LIS Operations Team will work with the STP-H5 and ISS Operations Teams to power-on LIS and begin instrument checkout and commissioning. Following successful activation, LIS orbital operations will commence, managed from the newly established LIS Payload Operations Control Center (POCC) located at the National Space Science Technology Center (NSSTC) in Huntsville, AL. The well-established and robust processing, archival, and distribution infrastructure used for TRMM was easily adapted to the ISS mission, assuring that lightning

  11. Design, synthesis and structure of new potential electrochemically active boronic acid-based glucose sensors

    DEFF Research Database (Denmark)

    Norrild, Jens Chr.; Søtofte, Inger

    2002-01-01

    In the course of our investigations on new boronic acid based carbohydrate sensors three new boronic acids 3, 7 and 11 containing a ferrocene moiety were synthesised. Their design includes an intramolecular B-N bonding motif in order to facilitate binding at physiological pH. We report the synthe......In the course of our investigations on new boronic acid based carbohydrate sensors three new boronic acids 3, 7 and 11 containing a ferrocene moiety were synthesised. Their design includes an intramolecular B-N bonding motif in order to facilitate binding at physiological pH. We report...... the synthesis of the compounds and our investigations on glucose complexation as studied by C-13 NMR spectroscopy. The crystal structure of 2,4,6-tris[2-(N-ferrocenylmethyl-N-methylaminomethyl) phenyl] boroxin (13) (boroxin of boronic acid 3) (boroxin = cyclotriboroxane) was obtained and compared...... with structures obtained of 2,4,6-tris[2-(N,N-dimethylaminomethyl)phenyl]boroxin (14) and 2,2-dimethyl-1,3-diyl[2-(N,N-dimethylaminomethyl)phenyl]boronate (15). The structure of 13 shows the existence of intramolecular B-N bonds in the solid phase....

  12. ALPIDE: the Monolithic Active Pixel Sensor for the ALICE ITS upgrade

    International Nuclear Information System (INIS)

    Šuljić, M.

    2016-01-01

    The upgrade of the ALICE vertex detector, the Inner Tracking System (ITS), is scheduled to be installed during the next long shutdown period (2019-2020) of the CERN Large Hadron Collider (LHC) . The current ITS will be replaced by seven concentric layers of Monolithic Active Pixel Sensors (MAPS) with total active surface of ∼10 m 2 , thus making ALICE the first LHC experiment implementing MAPS detector technology on a large scale. The ALPIDE chip, based on TowerJazz 180 nm CMOS Imaging Process, is being developed for this purpose. A particular process feature, the deep p-well, is exploited so the full CMOS logic can be implemented over the active sensor area without impinging on the deposited charge collection. ALPIDE is implemented on silicon wafers with a high resistivity epitaxial layer. A single chip measures 15 mm by 30 mm and contains half a million pixels distributed in 512 rows and 1024 columns. In-pixel circuitry features amplification, shaping, discrimination and multi-event buffering. The readout is hit driven i.e. only addresses of hit pixels are sent to the periphery. The upgrade of the ITS presents two different sets of requirements for sensors of the inner and of the outer layers due to the significantly different track density, radiation level and active detector surface. The ALPIDE chip fulfils the stringent requirements in both cases. The detection efficiency is higher than 99%, fake-hit probability is orders of magnitude lower than the required 10 −6 and spatial resolution within the required 5 μm. This performance is to be maintained even after a total ionising does (TID) of 2.7 Mrad and a non-ionising energy loss (NIEL) fluence of 1.7 × 10 13 1 MeV n eq /cm 2 , which is above what is expected during the detector lifetime. Readout rate of 100 kHz is provided and the power density of ALPIDE is less than 40 mW/cm 2 . This contribution will provide a summary of the ALPIDE features and main test results.

  13. ALPIDE: the Monolithic Active Pixel Sensor for the ALICE ITS upgrade

    Science.gov (United States)

    Šuljić, M.

    2016-11-01

    The upgrade of the ALICE vertex detector, the Inner Tracking System (ITS), is scheduled to be installed during the next long shutdown period (2019-2020) of the CERN Large Hadron Collider (LHC) . The current ITS will be replaced by seven concentric layers of Monolithic Active Pixel Sensors (MAPS) with total active surface of ~10 m2, thus making ALICE the first LHC experiment implementing MAPS detector technology on a large scale. The ALPIDE chip, based on TowerJazz 180 nm CMOS Imaging Process, is being developed for this purpose. A particular process feature, the deep p-well, is exploited so the full CMOS logic can be implemented over the active sensor area without impinging on the deposited charge collection. ALPIDE is implemented on silicon wafers with a high resistivity epitaxial layer. A single chip measures 15 mm by 30 mm and contains half a million pixels distributed in 512 rows and 1024 columns. In-pixel circuitry features amplification, shaping, discrimination and multi-event buffering. The readout is hit driven i.e. only addresses of hit pixels are sent to the periphery. The upgrade of the ITS presents two different sets of requirements for sensors of the inner and of the outer layers due to the significantly different track density, radiation level and active detector surface. The ALPIDE chip fulfils the stringent requirements in both cases. The detection efficiency is higher than 99%, fake-hit probability is orders of magnitude lower than the required 10-6 and spatial resolution within the required 5 μm. This performance is to be maintained even after a total ionising does (TID) of 2.7 Mrad and a non-ionising energy loss (NIEL) fluence of 1.7 × 1013 1 MeV neq/cm2, which is above what is expected during the detector lifetime. Readout rate of 100 kHz is provided and the power density of ALPIDE is less than 40 mW/cm2. This contribution will provide a summary of the ALPIDE features and main test results.

  14. Application Of FA Sensor 2

    International Nuclear Information System (INIS)

    Park, Seon Ho

    1993-03-01

    This book introduces FA sensor from basic to making system, which includes light sensor like photo diode and photo transistor, photo electricity sensor, CCD type image sensor, MOS type image sensor, color sensor, cds cell, and optical fiber scope. It also deals with direct election position sensor such as proximity switch, differential motion, linear scale of photo electricity type, and magnet scale, rotary sensor with summary of rotary encoder, rotary encoder types and applications, flow sensor, and sensing technology.

  15. Major features of immunesenescence, including reduced thymic output, are ameliorated by high levels of physical activity in adulthood.

    Science.gov (United States)

    Duggal, Niharika Arora; Pollock, Ross D; Lazarus, Norman R; Harridge, Stephen; Lord, Janet M

    2018-04-01

    It is widely accepted that aging is accompanied by remodelling of the immune system including thymic atrophy and increased frequency of senescent T cells, leading to immune compromise. However, physical activity, which influences immunity but declines dramatically with age, is not considered in this literature. We assessed immune profiles in 125 adults (55-79 years) who had maintained a high level of physical activity (cycling) for much of their adult lives, 75 age-matched older adults and 55 young adults not involved in regular exercise. The frequency of naïve T cells and recent thymic emigrants (RTE) were both higher in cyclists compared with inactive elders, and RTE frequency in cyclists was no different to young adults. Compared with their less active counterparts, the cyclists had significantly higher serum levels of the thymoprotective cytokine IL-7 and lower IL-6, which promotes thymic atrophy. Cyclists also showed additional evidence of reduced immunesenescence, namely lower Th17 polarization and higher B regulatory cell frequency than inactive elders. Physical activity did not protect against all aspects of immunesenescence: CD28 -ve CD57 +ve senescent CD8 T-cell frequency did not differ between cyclists and inactive elders. We conclude that many features of immunesenescence may be driven by reduced physical activity with age. © 2018 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  16. Noise activated bistable sensor based on chaotic system with output defined by temporal coding and firing rate.

    Science.gov (United States)

    Korneta, Wojciech; Gomes, Iacyel

    2017-11-01

    Traditional bistable sensors use external bias signal to drive its response between states and their detection strategy is based on the output power spectral density or the residence time difference (RTD) in two sensor states. Recently, the noise activated nonlinear dynamic sensors driven only by noise based on RTD technique have been proposed. Here, we present experimental results of dc voltage measurements by noise-driven bistable sensor based on electronic Chua's circuit operating in a chaotic regime where two single scroll attractors coexist. The output of the sensor is quantified by the proportion of the time the sensor stays in one state to the total observation time and by the spike-count rate with spikes defined by crossings between attractors. The relationship between the stimuli and particular observable for different noise intensities is obtained, the usefulness of each coding scheme is discussed, and the optimal noise intensity for detection is indicated. It is shown that the obtained relationship is the same for any observation time when population coding is used. The optimal time window for both detection and the number of units in population coding is found. Our results may be useful for analyses and understanding of the neural activity and in designing bistable storage elements at length scales where thermal fluctuations drastically increase and the effect of noise must be taken into consideration.

  17. Bio-Inspired Carbon Monoxide Sensors with Voltage-Activated Sensitivity

    KAUST Repository

    Savagatrup, Suchol; Schroeder, Vera; He, Xin; Lin, Sibo; He, Maggie; Yassine, Omar; Salama, Khaled N.; Zhang, Xixiang; Swager, Timothy M.

    2017-01-01

    voltage offers a predicted extra dimension for sensing. Specifically, the sensors show a significant increase in sensitivity toward CO when negative gate voltage is applied. The dosimetric sensors are selective to ppm levels of CO and functional in air. UV

  18. Chromospheric activity of periodic variable stars (including eclipsing binaries) observed in DR2 LAMOST stellar spectral survey

    Science.gov (United States)

    Zhang, Liyun; Lu, Hongpeng; Han, Xianming L.; Jiang, Linyan; Li, Zhongmu; Zhang, Yong; Hou, Yonghui; Wang, Yuefei; Cao, Zihuang

    2018-05-01

    The LAMOST spectral survey provides a rich databases for studying stellar spectroscopic properties and chromospheric activity. We cross-matched a total of 105,287 periodic variable stars from several photometric surveys and databases (CSS, LINEAR, Kepler, a recently updated eclipsing star catalogue, ASAS, NSVS, some part of SuperWASP survey, variable stars from the Tsinghua University-NAOC Transient Survey, and other objects from some new references) with four million stellar spectra published in the LAMOST data release 2 (DR2). We found 15,955 spectra for 11,469 stars (including 5398 eclipsing binaries). We calculated their equivalent widths (EWs) of their Hα, Hβ, Hγ, Hδ and Caii H lines. Using the Hα line EW, we found 447 spectra with emission above continuum for a total of 316 stars (178 eclipsing binaries). We identified 86 active stars (including 44 eclipsing binaries) with repeated LAMOST spectra. A total of 68 stars (including 34 eclipsing binaries) show chromospheric activity variability. We also found LAMOST spectra of 12 cataclysmic variables, five of which show chromospheric activity variability. We also made photometric follow-up studies of three short period targets (DY CVn, HAT-192-0001481, and LAMOST J164933.24+141255.0) using the Xinglong 60-cm telescope and the SARA 90-cm and 1-m telescopes, and obtained new BVRI CCD light curves. We analyzed these light curves and obtained orbital and starspot parameters. We detected the first flare event with a huge brightness increase of more than about 1.5 magnitudes in R filter in LAMOST J164933.24+141255.0.

  19. Sensing capabilities of piezoelectric wafer active sensors in extreme nuclear environment

    Science.gov (United States)

    Faisal Haider, Mohammad; Lin, Bin; Yu, Lingyu; Giurgiutiu, Victor

    2017-04-01

    There is considerable demand for structural health monitoring (SHM) at locations where there are substantial radiation fields such as nuclear reactor components, dry cask storage canister, irradiated fuel assemblies, etc. Piezoelectric wafer active sensors (PWAS) have been emerged as one of the major SHM sensing technologies. In order to use PWAS to perform SHM in nuclear environment, radiation influence on sensor and sensing capability needs to be investigated to assure the reliability of the PWAS based method. Radiation may cause degradation or even complete failure of sensors. Gamma radiation is one of the major radiation sources near the nuclear source. Therefore, experimental investigation was completed on the gamma radiation endurance of piezoelectric sensors. The irradiation test was done in a Co-60 Gamma Irradiator. Lead Zirconate Titanate (PZT) and Gallium Orthophosphate (GaPO4) PWAS were exposed under gamma radiation at 100 Gy/hr rate for 20 hours. Electro-mechanical (E/M) admittance signatures and electrical capacitance were measured to evaluate the PWAS performance before and after every 4 hours exposure to gamma radiation. PWAS were kept at room temperature for 6 days after each 4 hours radiation exposure to investigate the effect of time on PWAS by gamma radiation. It was found that, PZT-PWAS show variation in resonance frequency for both in plane and thickness mode E/M admittance. Where, the changes in resonance amplitudes are larger for PZT-PWAS. GaPO4-PWAS E/M impedance/admittance spectra don't show any reasonable change after gamma irradiation. A degradation behavior of electrical properties in the PZT-PWAS was observed. Capacitance value of PZT-PWAS decreases from 3.2 nF to 3.07 nF after exposing to gamma radiation for 20 hours at 100Gy/hour. This degradation behavior of electrical properties may be explained by the pinning of domain walls by some radiation induced effect. GaPO4-PWAS doesn't show reasonable degradation in electrical properties

  20. 3D monolithically stacked CMOS active pixel sensor detectors for particle tracking applications

    International Nuclear Information System (INIS)

    Passeri, D; Placidi, P; Servoli, L; Meroli, S; Magalotti, D; Marras, A

    2012-01-01

    In this work we propose an innovative approach to particle tracking based on CMOS Active Pixel Sensors layers, monolithically integrated in an all-in-one chip featuring multiple, stacked, fully functional detector layers capable to provide momentum measurement (particle impact point and direction) within a single detector. This will results in a very low material detector, thus dramatically reducing multiple scattering issues. To this purpose, we rely on the capabilities of the CMOS vertical scale integration (3D IC) technology. A first chip prototype has been fabricated within a multi-project run using a 130 nm CMOS Chartered/Tezzaron technology, featuring two layers bonded face-to-face. Tests have been carried out on full 3D structures, providing the functionalities of both tiers. To this purpose, laser scans have been carried out using highly focussed spot size obtaining coincidence responses of the two layers. Tests have been made as well with X-ray sources in order to calibrate the response of the sensor. Encouraging results have been found, fostering the suitability of both the adopted 3D-IC vertical scale fabrication technology and the proposed approach for particle tracking applications.

  1. Theoretical and experimental studies on the electric impedance of active piezoelectric sensors bonded on cracked beams

    International Nuclear Information System (INIS)

    Kuang, Y D; Chen, C Y; Shi, S Q; Chan, P K L; He, X Q

    2010-01-01

    The electric impedance of symmetrically surface-bonded piezoelectric sensors on a cracked beam is studied. To investigate the effect of the crack on the electric impedance in a convenient fashion, an analytical expression is derived that is correlated to the physical parameters of the crack and the host beam. The beam segment covered with piezoelectric patches and the cracked region are regarded as a bimorph segment and an equivalent spring, respectively, and the entire beam system is then represented by three elastic beam segments and a bimorph segment together with the spring. Electric impedance experiments are also conducted for uncracked beams and for cracked beams with single-edge or double-edge cracks. The experimental results agree with those generated by the analytical expression. The crack depth has little effect on the corresponding mode frequency for cracks located at the mode node of a beam. For cracks located away from the mode node, the corresponding mode frequency decreases as the crack depth increases. Moreover, the closer the crack to the anti-node of the mode, the greater the decrease in the corresponding mode frequency. The mechanism of these changes is discussed. The findings should prove helpful for structural health monitoring using active piezoelectric sensors

  2. Characterization study of an intensified complementary metal-oxide-semiconductor active pixel sensor

    Science.gov (United States)

    Griffiths, J. A.; Chen, D.; Turchetta, R.; Royle, G. J.

    2011-03-01

    An intensified CMOS active pixel sensor (APS) has been constructed for operation in low-light-level applications: a high-gain, fast-light decay image intensifier has been coupled via a fiber optic stud to a prototype "VANILLA" APS, developed by the UK based MI3 consortium. The sensor is capable of high frame rates and sparse readout. This paper presents a study of the performance parameters of the intensified VANILLA APS system over a range of image intensifier gain levels when uniformly illuminated with 520 nm green light. Mean-variance analysis shows the APS saturating around 3050 Digital Units (DU), with the maximum variance increasing with increasing image intensifier gain. The system's quantum efficiency varies in an exponential manner from 260 at an intensifier gain of 7.45 × 103 to 1.6 at a gain of 3.93 × 101. The usable dynamic range of the system is 60 dB for intensifier gains below 1.8 × 103, dropping to around 40 dB at high gains. The conclusion is that the system shows suitability for the desired application.

  3. Intrusion detection sensors

    International Nuclear Information System (INIS)

    Williams, J.D.

    1978-07-01

    Intrusion detection sensors are an integral part of most physical security systems. Under the sponsorship of the U.S. Department of Energy, Office of Safeguards and Security, Sandia Laboratories has conducted a survey of available intrusion detection sensors and has tested a number of different sensors. An overview of these sensors is provided. This overview includes (1) the operating principles of each type of sensor, (2) unique sensor characteristics, (3) desired sensor improvements which must be considered in planning an intrusion detection system, and (4) the site characteristics which affect the performance of both exterior and interior sensors. Techniques which have been developed to evaluate various intrusion detection sensors are also discussed

  4. Sensor web

    Science.gov (United States)

    Delin, Kevin A. (Inventor); Jackson, Shannon P. (Inventor)

    2011-01-01

    A Sensor Web formed of a number of different sensor pods. Each of the sensor pods include a clock which is synchronized with a master clock so that all of the sensor pods in the Web have a synchronized clock. The synchronization is carried out by first using a coarse synchronization which takes less power, and subsequently carrying out a fine synchronization to make a fine sync of all the pods on the Web. After the synchronization, the pods ping their neighbors to determine which pods are listening and responded, and then only listen during time slots corresponding to those pods which respond.

  5. Review of neutron activation analysis in the standardization and study of reference materials, including its application to radionuclide reference materials

    International Nuclear Information System (INIS)

    Byrne, A.R.

    1993-01-01

    Neutron activation analysis (NAA) plays a very important role in the certification of reference materials (RMs) and their characterization, including homogeneity testing. The features of the method are briefly reviewed, particularly aspects relating to its completely independent nuclear basis, its virtual freedom from blank problems, and its capacity for self-verification. This last aspect, arising from the essentially isotopic character of NAA, can be exploited by using different nuclear reactions and induced nuclides, and the possibility of employing two modes, one instrumental (nondestructive), the other radiochemical (destructive). This enables the derivation of essentially independent analytical information and the unique capacity of NAA for selfvalidation. The application of NAA to quantify natural or man-made radionuclides such as uranium, thorium, 237 Np, 129 I and 230 Th is discussed, including its advantages over conventional radiometric methods and its usefulness in providing independent data for nuclides where other confirmatory analyses are impossible, or are only recently becoming available through newer 'atom counting' techniques. Certain additional, prospective uses of NAA in the study of RMs and potential RMs are mentioned, including transmutation reactions, creation of endogenously radiolabelled matrices for production and study of RMs (such as dissolution and leaching tests, use as incorporated radiotracers for chemical recovery correction), and the possibility of molecular activation analysis for specification. (orig.)

  6. A market based active/reactive dispatch including transformer taps and reactor and capacitor banks using Simulated Annealing

    International Nuclear Information System (INIS)

    Gomes, Mario Helder; Saraiva, Joao Tome

    2009-01-01

    This paper describes an optimization model to be used by System Operators in order to validate the economic schedules obtained by Market Operators together with the injections from Bilateral Contracts. These studies will be performed off-line in the day before operation and the developed model is based on adjustment bids submitted by generators and loads and it is used by System Operators if that is necessary to enforce technical or security constraints. This model corresponds to an enhancement of an approach described in a previous paper and it now includes discrete components as transformer taps and reactor and capacitor banks. The resulting mixed integer formulation is solved using Simulated Annealing, a well known metaheuristic specially suited for combinatorial problems. Once the Simulated Annealing converges and the values of the discrete variables are fixed, the resulting non-linear continuous problem is solved using Sequential Linear Programming to get the final solution. The developed model corresponds to an AC version, it includes constraints related with the capability diagram of synchronous generators and variables allowing the computation of the active power required to balance active losses. Finally, the paper includes a Case Study based on the IEEE 118 bus system to illustrate the results that it is possible to obtain and their interest. (author)

  7. Review of the IAEA nuclear fuel cycle and material section activities connected with nuclear fuel including WWER fuel

    International Nuclear Information System (INIS)

    Sokolov, F.

    2001-01-01

    Program activities on Nuclear Fuel Cycle and Materials cover the areas of: 1) raw materials (B.1.01); 2) fuel performance and technology (B.1.02); 3) pent fuel (B.1.03); 4) fuel cycle issues and information system (B.1.04); 5) support to technical cooperation activities (B.1.05). The IAEA activities in fuel performance and technology in 2001 include organization of the fuel experts meetings and completion of the Co-ordinate Research Projects (CRP). The special attention is given to the advanced post-irradiation examination techniques for water reactor fuel and fuel behavior under transients and LOCA conditions. An international research program on modeling of activity transfer in primary circuit of NPP is finalized in 2001. A new CRP on fuel modeling at extended burnup (FUMEX II) has planed to be carried out during the period 2002-2006. In the area of spent fuel management the implementation of burnup credit (BUC) in spent fuel management systems has motivated to be used in criticality safety applications, based on economic consideration. An overview of spent fuel storage policy accounting new fuel features as higher enrichment and final burnup, usage of MOX fuel and prolongation of the term of spent fuel storage is also given

  8. A novel simulation method to evaluate the collection performance of a monolithic active pixel sensor

    International Nuclear Information System (INIS)

    Fu Min; Tang Zhen'an

    2011-01-01

    A novel simulation method is presented in this paper to evaluate the collection performance of monolithic active pixel sensor (MAPS) devices for minimum ionizing particle tracking. A simplified 3D matrix pixel structure is built using the computer aided design software Sentaurus. The virtual device is then divided into hundreds of parts and an independent customized X photon model is involved in each part to simulate the conditions under 55 Fe radiation. After data processing and analysis, charge collection efficiency, collection time and diffusion conditions can be estimated in detail. In order to verify the reliability of the method, comparisons are made between the simulations and experiments. Although there are some defects, it can be concluded that the proposed idea is a feasible method for the evaluation of the MAPS collection performance. (authors)

  9. Comparison of POLDER Cloud Phase Retrievals to Active Remote Sensors Measurements at the ARM SGP Site

    International Nuclear Information System (INIS)

    Riedi, J.; Goloub, P.; Marchand, Roger T.

    2001-01-01

    In our present study, cloud boundaries derived from a combination of active remote sensors at the ARM SGP site are compared to POLDER cloud top phase index which is derived from polarimetric measurements using an innovative method. This approach shows the viability of the POLDER phase retrieval algorithm, and also leads to interesting results. In particular, the analysis demonstrates the sensitivity of polarization measurements to ice crystal shape and indicates that occurrence of polycrystalline ice clouds has to be taken into account in order to improve the POLDER phase retrieval algorithm accuracy. Secondly, the results show that a temperature threshold of 240 K could serve for cloud top particle phase classification. Considering the limitations of the analysis, the temperature threshold could be biased high, but not by more than about 5 degrees

  10. Finite element analysis of actively controlled smart plate with patched actuators and sensors

    Directory of Open Access Journals (Sweden)

    M. Yaqoob Yasin

    Full Text Available The active vibration control of smart plate equipped with patched piezoelectric sensors and actuators is presented in this study. An equivalent single layer third order shear deformation theory is employed to model the kinematics of the plate and to obtain the shear strains. The governing equations of motion are derived using extended Hamilton's principle. Linear variation of electric potential across the piezoelectric layers in thickness direction is considered. The electrical variable is discretized by Lagrange interpolation function considering two-noded line element. Undamped natural frequencies and the corresponding mode shapes are obtained by solving the eigen value problem with and without electromechanical coupling. The finite element model in nodal variables are transformed into modal model and then recast into state space. The dynamic model is reduced for further analysis using Hankel norm for designing the controller. The optimal control technique is used to control the vibration of the plate.

  11. Study of plasma charging-induced white pixel defect increase in CMOS active pixel sensor

    International Nuclear Information System (INIS)

    Tokashiki, Ken; Bai, KeunHee; Baek, KyeHyun; Kim, Yongjin; Min, Gyungjin; Kang, Changjin; Cho, Hanku; Moon, Jootae

    2007-01-01

    Plasma process-induced 'white pixel defect' (WPD) of CMOS active pixel sensor (APS) is studied for Si3N4 spacer etch back process by using a magnetically enhanced reactive ion etching (MERIE) system. WPD preferably takes place at the wafer edge region when the magnetized plasma is applied to Si3N4 etch. Plasma charging analysis reveals that the plasma charge-up characteristic is well matching the edge-intensive WPD generation, rather than the UV radiation. Plasma charging on APS transfer gate might lead to a gate leakage, which could play a role in generation of signal noise or WPD. In this article the WPD generation mechanism will be discussed from plasma charging point of view

  12. A radiation-hardened two transistor memory cell for monolithic active pixel sensors in STAR experiment

    International Nuclear Information System (INIS)

    Wei, X; Dorokhov, A; Hu, Y; Gao, D

    2011-01-01

    Radiation tolerance of Monolithic Active Pixel Sensors (MAPS) is dramatically decreased when intellectual property (IP) memories are integrated for fast readout application. This paper presents a new solution to improve radiation hardness and avoid latch-up for memory cell design. The tradeoffs among radiation tolerance, area and speed are significantly considered and analyzed. The cell designed in 0.35 μm process satisfies the radiation tolerance requirements of STAR experiment. The cell size is 4.55 x 5.45 μm 2 . This cell is smaller than the IP memory cell based on the same process and is only 26% of a radiation tolerant 6T SRAM cell used in previous contribution. The write access time of the cell is less than 2 ns, while the read access time is 80 ns.

  13. Proof of principle study of the use of a CMOS active pixel sensor for proton radiography.

    Science.gov (United States)

    Seco, Joao; Depauw, Nicolas

    2011-02-01

    Proof of principle study of the use of a CMOS active pixel sensor (APS) in producing proton radiographic images using the proton beam at the Massachusetts General Hospital (MGH). A CMOS APS, previously tested for use in s-ray radiation therapy applications, was used for proton beam radiographic imaging at the MGH. Two different setups were used as a proof of principle that CMOS can be used as proton imaging device: (i) a pen with two metal screws to assess spatial resolution of the CMOS and (ii) a phantom with lung tissue, bone tissue, and water to assess tissue contrast of the CMOS. The sensor was then traversed by a double scattered monoenergetic proton beam at 117 MeV, and the energy deposition inside the detector was recorded to assess its energy response. Conventional x-ray images with similar setup at voltages of 70 kVp and proton images using commercial Gafchromic EBT 2 and Kodak X-Omat V films were also taken for comparison purposes. Images were successfully acquired and compared to x-ray kVp and proton EBT2/X-Omat film images. The spatial resolution of the CMOS detector image is subjectively comparable to the EBT2 and Kodak X-Omat V film images obtained at the same object-detector distance. X-rays have apparent higher spatial resolution than the CMOS. However, further studies with different commercial films using proton beam irradiation demonstrate that the distance of the detector to the object is important to the amount of proton scatter contributing to the proton image. Proton images obtained with films at different distances from the source indicate that proton scatter significantly affects the CMOS image quality. Proton radiographic images were successfully acquired at MGH using a CMOS active pixel sensor detector. The CMOS demonstrated spatial resolution subjectively comparable to films at the same object-detector distance. Further work will be done in order to establish the spatial and energy resolution of the CMOS detector for protons. The

  14. A Personalised, Sensor-Based Smart Phone Intervention for Physical Activity and Diet – PRECIOUS N-of-1 Trial

    Directory of Open Access Journals (Sweden)

    Johanna Nurmi

    2015-10-01

    Full Text Available Background: There is an urgent need for interventions which can effectively change behaviours, in order to prevent and reduce the impact of costly chronic conditions such as Type 2 diabetes and cardiovascular diseases (WHO, 2014. Smartphones offer a platform for cost-effective and broad implementation, and at the same time, via real-time tracking and sensor data, offer unprecedented possibilities for personalising interventions (Jovanov & Milenkovic, 2011. While a great number of health-related applications exist already, the content of these is rarely based on behaviour change theory, and, consequently, evidence for the effectiveness of digital behaviour change applications is minimal (Webb, Joseph, Yardley, & Michie, 2010. Even when health-related applications are theory-based, users will likely not achieve behavioural changes if they do not engage with the applications. This lack of engagement is supported by statistics: a quarter of downloaded apps were only used once (Leger, 2011. A major challenge of health care research is therefore the identification of personal treatment response, and factors which mitigate engagement and effectiveness within individuals. To address these issues, our research group, an EU-funded multi-disciplinary consortium has developed the PREventitive Care Infrastructure based On Ubiquitous Sensing (PRECIOUS mobile application. This app targets behavioural changes in physical activity, diet, and stress, and includes both motivational and action components for each. The service design draws from evidence-based techniques in self-determination theory (SDT, Deci & Ryan, 2000, motivational interviewing (MI, Miller & Rollnick, 2002, and social cognitive theories (e.g. Schwarzer, 2008, to enhance engagement with the process of behaviour change. Through integrating sensor data, self-reported responses, and self-monitoring records, the system provides each user with a dynamic, personalised trajectory through the app

  15. Empirical electro-optical and x-ray performance evaluation of CMOS active pixels sensor for low dose, high resolution x-ray medical imaging

    International Nuclear Information System (INIS)

    Arvanitis, C. D.; Bohndiek, S. E.; Royle, G.; Blue, A.; Liang, H. X.; Clark, A.; Prydderch, M.; Turchetta, R.; Speller, R.

    2007-01-01

    Monolithic complementary metal oxide semiconductor (CMOS) active pixel sensors with high performance have gained attention in the last few years in many scientific and space applications. In order to evaluate the increasing capabilities of this technology, in particular where low dose high resolution x-ray medical imaging is required, critical electro-optical and physical x-ray performance evaluation was determined. The electro-optical performance includes read noise, full well capacity, interacting quantum efficiency, and pixels cross talk. The x-ray performance, including x-ray sensitivity, modulation transfer function, noise power spectrum, and detection quantum efficiency, has been evaluated in the mammographic energy range. The sensor is a 525x525 standard three transistor CMOS active pixel sensor array with more than 75% fill factor and 25x25 μm pixel pitch. Reading at 10 f/s, it is found that the sensor has 114 electrons total additive noise, 10 5 electrons full well capacity with shot noise limited operation, and 34% interacting quantum efficiency at 530 nm. Two different structured CsI:Tl phosphors with thickness 95 and 115 μm, respectively, have been optically coupled via a fiber optic plate to the array resulting in two different system configurations. The sensitivity of the two different system configurations was 43 and 47 electrons per x-ray incident on the sensor. The MTF at 10% of the two different system configurations was 9.5 and 9 cycles/mm with detective quantum efficiency of 0.45 and 0.48, respectively, close to zero frequency at ∼0.44 μC/kg (1.72 mR) detector entrance exposure. The detector was quantum limited at low spatial frequencies and its performance was comparable with high resolution a:Si and charge coupled device based x-ray imagers. The detector also demonstrates almost an order of magnitude lower noise than active matrix flat panel imagers. The results suggest that CMOS active pixel sensors when coupled to structured CsI:Tl can

  16. Physical activity interventions in Latin America: what value might be added by including conference abstracts in a literature review?

    Science.gov (United States)

    Hoehner, Christine; Soares, Jesus; Parra, Diana C; Ribeiro, Isabela C; Pratt, Michael; Bracco, Mario; Hallal, Pedro C; Brownson, Ross C

    2010-07-01

    This review assessed whether conference abstracts yield useful information on the types and effectiveness of community-based physical activity (PA) interventions in Latin America, beyond that from interventions included in a recent systematic review of peer-reviewed literature. Abstracts from 9 conferences were searched for community-based interventions to promote PA in Latin America and summarized. Three reviewers classified and screened abstracts. Evaluated interventions that were not included in the previous review were assessed. Search of abstracts from 31 proceedings of 9 conferences identified 87 abstracts of studies on community-based interventions focused on increasing PA. Only 31 abstracts reported on studies with a control group and an outcome related to PA. Ten of these abstracts represented interventions that had not been included in the previous review of peer-reviewed literature, but the abstracts were insufficient in number or detail to make a practice recommendation for any single intervention. This review highlighted the challenges and low added value of including conference abstracts in a systematic review of community PA interventions in Latin America. Stronger evaluation design and execution and more published reports of evaluated interventions are needed to build an evidence base supporting interventions to increase PA in Latin America.

  17. Highly sensitive multi-layer pressure sensor with an active nanostructured layer of an organic molecular metal

    International Nuclear Information System (INIS)

    Laukhin, V; Lebedev, V; Laukhina, E; Rovira, C; Veciana, J

    2016-01-01

    This work addresses to the modern technologies that need to be instrumented with lightweight highly sensitive pressure sensors. The paper presents the development of a new plain flexible thin pressure sensor using a nanostructured layer of the highly sensitive organic piezoresistive metal β-(BEDT-TTF) 2 I 3 as an active component; BEDT-TTF=bis (ethylenedithio)tetrathiafulvalene. The original construction approach permits one to operate the developed sensor on the principle of electrical resistance variations when its piezoresistive layer is elongated under a pressure increase. The pressure sensing element and a set of gold electrodes were integrated into one compact multi-layer design. The construction was optimized to enable one generic design for pressure ranges from 1 to 400 bar. The pressure tests showed that the sensor is able to control a small pressure change as a well definite electrical signal. So the developed type of the sensors is very attractive as a new generation of compact, lightweight, low-cost sensors that might monitor pressure with a good level of measurement accuracy. (paper)

  18. Wireless sensor platform

    Science.gov (United States)

    Joshi, Pooran C.; Killough, Stephen M.; Kuruganti, Phani Teja

    2017-08-08

    A wireless sensor platform and methods of manufacture are provided. The platform involves providing a plurality of wireless sensors, where each of the sensors is fabricated on flexible substrates using printing techniques and low temperature curing. Each of the sensors can include planar sensor elements and planar antennas defined using the printing and curing. Further, each of the sensors can include a communications system configured to encode the data from the sensors into a spread spectrum code sequence that is transmitted to a central computer(s) for use in monitoring an area associated with the sensors.

  19. Nanomaterial-Enabled Wearable Sensors for Healthcare.

    Science.gov (United States)

    Yao, Shanshan; Swetha, Puchakayala; Zhu, Yong

    2018-01-01

    Highly sensitive wearable sensors that can be conformably attached to human skin or integrated with textiles to monitor the physiological parameters of human body or the surrounding environment have garnered tremendous interest. Owing to the large surface area and outstanding material properties, nanomaterials are promising building blocks for wearable sensors. Recent advances in the nanomaterial-enabled wearable sensors including temperature, electrophysiological, strain, tactile, electrochemical, and environmental sensors are presented in this review. Integration of multiple sensors for multimodal sensing and integration with other components into wearable systems are summarized. Representative applications of nanomaterial-enabled wearable sensors for healthcare, including continuous health monitoring, daily and sports activity tracking, and multifunctional electronic skin are highlighted. Finally, challenges, opportunities, and future perspectives in the field of nanomaterial-enabled wearable sensors are discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Retrieval of the photochemical reflectance index for assessing xanthophyll cycle activity: a comparison of near-surface optical sensors

    Science.gov (United States)

    Harris, A.; Gamon, J. A.; Pastorello, G. Z.; Wong, C. Y. S.

    2014-11-01

    Unattended optical sensors are increasingly being deployed on eddy covariance flux towers and are often used to complement existing vegetation and micrometeorological measurements to enable assessment of biophysical states and biogeochemical processes over a range of spatial scales. Of particular interest are sensors that can measure the photochemical reflectance index (PRI), which can provide information pertaining to leaf pigments and photosynthetic activity. This interest has facilitated the production of a new range of lower-cost multispectral sensors specifically designed to measure temporal changes in the PRI signal. However, little is known about the characteristics (spectral, radiometric and temporal) of many of these PRI sensors, making it difficult to compare data obtained from these sensors across time, geographical locations and instruments. Furthermore, direct testing of the capability of these sensors to actually detect the conversion of the xanthophyll cycle, which is the original biological basis of the PRI diurnal signal, is largely absent, often resulting in an unclear interpretation of the signal, particularly given the wide range of factors now known to influence PRI. Through a series of experiments, we assess the sensitivity of one of the leading brands of PRI sensor (Skye SKR 1800) to changes in vegetation photosynthetic activity in response to changing irradiance. We compare the results with those obtained using a more expensive industry-standard visible to near-infrared hyperspectral spectrometer (PP Systems UniSpec) and determine the radiometric compatibility of measurements made by the different instruments. Results suggest that the SKR 1800 instrument is able to track rapid (seconds to minutes) and more gradual diurnal changes in photosynthetic activity associated with xanthophyll cycle pigment conversion. Measurements obtained from both the high and lower cost instrument were significantly linearly correlated but were subject to a large

  1. Alkali metals in addition to acidic pH activate the EvgS histidine kinase sensor in Escherichia coli.

    Science.gov (United States)

    Eguchi, Yoko; Utsumi, Ryutaro

    2014-09-01

    Two-component signal transduction systems (TCSs) in bacteria perceive environmental stress and transmit the information via phosphorelay to adjust multiple cellular functions for adaptation. The EvgS/EvgA system is a TCS that confers acid resistance to Escherichia coli cells. Activation of the EvgS sensor initiates a cascade of transcription factors, EvgA, YdeO, and GadE, which induce the expression of a large group of acid resistance genes. We searched for signals activating EvgS and found that a high concentration of alkali metals (Na(+), K(+)) in addition to low pH was essential for the activation. EvgS is a histidine kinase, with a large periplasmic sensor region consisting of two tandem PBPb (bacterial periplasmic solute-binding protein) domains at its N terminus. The periplasmic sensor region of EvgS was necessary for EvgS activation, and Leu152, located within the first PBPb domain, was involved in the activation. Furthermore, chimeras of EvgS and PhoQ histidine kinases suggested that alkali metals were perceived at the periplasmic sensor region, whereas the cytoplasmic linker domain, connecting the transmembrane region and the histidine kinase domain, was required for low-pH perception. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  2. Chemical sensors

    International Nuclear Information System (INIS)

    Hubbard, C.W.; Gordon, R.L.

    1987-05-01

    The revolution in analytical chemistry promised by recent developments in the field of chemical sensors has potential for significant positive impact on both research and production activities conducted by and for the Department of Energy. Analyses which were, in the past, performed only with a roomful of expensive equipment can now be performed with miniature solid-state electronic devices or small optical probes. Progress in the development of chemical sensors has been rapid, and the field is currently growing at a great rate. In accordance, Pacific Northwest Laboratory initiated a survey of recent literature so that contributors to active programs in research on analytical methods could be made aware of principles and applications of this new technology. This report presents the results of that survey. The sensors discussed here are divided into three types: micro solid-state devices, optical sensors, and piezoelectric crystal devices. The report is divided into three corresponding sections. The first section, ''Micro Solid-State Devices,'' discusses the design, operation, and application of electronic sensors that are produced in much the same way as standard solid-state electronic devices. The second section, ''Optrodes,'' covers the design and operation of chemical sensors that use fiber optics to detect chemically induced changes in optical properties. The final section, ''Piezoelectric Crystal Detectors,'' discusses two types of chemical sensors that depend on the changes in the properties of an oscillating piezoelectric crystal to detect the presence of certain materials. Advantages and disadvantages of each type of sensor are summarized in each section

  3. Estimating physical activity energy expenditure with the Kinect Sensor in an exergaming environment.

    Directory of Open Access Journals (Sweden)

    David Nathan

    Full Text Available Active video games that require physical exertion during game play have been shown to confer health benefits. Typically, energy expended during game play is measured using devices attached to players, such as accelerometers, or portable gas analyzers. Since 2010, active video gaming technology incorporates marker-less motion capture devices to simulate human movement into game play. Using the Kinect Sensor and Microsoft SDK this research aimed to estimate the mechanical work performed by the human body and estimate subsequent metabolic energy using predictive algorithmic models. Nineteen University students participated in a repeated measures experiment performing four fundamental movements (arm swings, standing jumps, body-weight squats, and jumping jacks. Metabolic energy was captured using a Cortex Metamax 3B automated gas analysis system with mechanical movement captured by the combined motion data from two Kinect cameras. Estimations of the body segment properties, such as segment mass, length, centre of mass position, and radius of gyration, were calculated from the Zatsiorsky-Seluyanov's equations of de Leva, with adjustment made for posture cost. GPML toolbox implementation of the Gaussian Process Regression, a locally weighted k-Nearest Neighbour Regression, and a linear regression technique were evaluated for their performance on predicting the metabolic cost from new feature vectors. The experimental results show that Gaussian Process Regression outperformed the other two techniques by a small margin. This study demonstrated that physical activity energy expenditure during exercise, using the Kinect camera as a motion capture system, can be estimated from segmental mechanical work. Estimates for high-energy activities, such as standing jumps and jumping jacks, can be made accurately, but for low-energy activities, such as squatting, the posture of static poses should be considered as a contributing factor. When translated into the

  4. Implementation of Human-Machine Synchronization Control for Active Rehabilitation Using an Inertia Sensor

    Directory of Open Access Journals (Sweden)

    Zhibin Song

    2012-11-01

    Full Text Available According to neuro-rehabilitation practice, active training is effective for mild stroke patients, which means these patients are able to recovery effective when they perform the training to overcome certain resistance by themselves. Therefore, for rehabilitation devices without backdrivability, implementation of human-machine synchronization is important and a precondition to perform active training. In this paper, a method to implement this precondition is proposed and applied in a user’s performance of elbow flexions and extensions when he wore an upper limb exoskeleton rehabilitation device (ULERD, which is portable, wearable and non-backdrivable. In this method, an inertia sensor is adapted to detect the motion of the user’s forearm. In order to get a smooth value of the velocity of the user’s forearm, an adaptive weighted average filtering is applied. On the other hand, to obtain accurate tracking performance, a double close-loop control is proposed to realize real-time and stable tracking. Experiments have been conducted to prove that these methods are effective and feasible for active rehabilitation.

  5. Study of Monolithic Active Pixel Sensors for the Upgrade of the ALICE Inner Tracking System

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00531401

    The upgrade of the ALICE vertex detector, the Inner Tracking System (ITS), is scheduled to be installed during the next long shutdown period (LS2 in 2019-2020) of the CERN Large Hadron Collider (LHC). The current ITS will be replaced by seven concentric layers of Monolithic Active Pixel Sensors (MAPS) with total active surface of $\\sim$10 m$^2$, thus making ALICE the first LHC experiment implementing MAPS detector technology on a large scale. The scope of this thesis is twofold; to report on the activity on the development and the characterisation of a MAPS for the ITS upgrade and to study the charge collection process using a first-principles Monte Carlo simulation. The performance of a MAPS depends on a large number of design and operational parameters, such as collection diode geometry, reverse bias voltage, and epitaxial layer thickness. I have studied this dependence by measuring the INVESTIGATOR chip response to X-rays emitted by an $^{55}$Fe source and to minimum ionising particles. In particular, I ha...

  6. Amperometric NOx-sensor for Combustion Exhaust Gas Control. Studies on transport properties and catalytic activity of oxygen permeable ceramic membranes

    International Nuclear Information System (INIS)

    Romer, E.W.J.

    2001-01-01

    The aim of the research described in this thesis is the development of a mixed conducting oxide layer, which can be used as an oxygen permselective membrane in an amperometric NOx sensor. The sensor will be used in exhaust gas systems. The exhaust gas-producing engine will run in the lean mix mode. The preparation of this sensor is carried out using screen-printing technology, in which the different layers of the sensor are applied successively. Hereafter, a co-firing step is applied in which all layers are sintered together. This co-firing step imposes several demands on the selection of materials. The design specifications of the sensor further include requirements concerning the operating temperature, measurement range and overall stability. The operating temperature of the sensor varies between 700 and 850C, enabling measurement of NOx concentrations between 50 and 1200 ppm with a measurement accuracy of 10 ppm. Concerning the stability of the sensor, it must withstand the exhaust gas atmosphere containing, amongst others, smoke, acids, abrasive particles and sulphur. Because of the chosen lean-mix engine concept, in which the fuel/air mixture switches continuously between lean (excess oxygen) and fat (excess fuel) mixtures, the sensor must withstand alternately oxidising and reducing atmospheres. Besides, it should be resistant to thermal shock and show no cross-sensitivity of NOx with other exhaust gas constituents like oxygen and hydrocarbons. The response time should be short, typically less than 500 ms. Because of the application in combustion engines of cars, the operational lifetime should be longer than 10 years. Demands on the mixed conducting oxide layer include the following ones. The layer should show minimal catalytic activity towards NOx-reduction. The oxygen permeability must be larger than 6.22 10 -8 mol/cm 2 s at a layer thickness between 3-50 μm. Since the mixed conducting oxide layer is coated on the YSZ electrolyte embodiment, the two

  7. Evaluating different approaches to non-destructive nitrogen status diagnosis of rice using portable RapidSCAN active canopy sensor.

    Science.gov (United States)

    Lu, Junjun; Miao, Yuxin; Shi, Wei; Li, Jingxin; Yuan, Fei

    2017-10-26

    RapidSCAN is a new portable active crop canopy sensor with three wavebands in red, red-edge, and near infrared spectral regions. The objective of this study was to determine the potential and practical approaches of using this sensor for non-destructive diagnosis of rice nitrogen (N) status. Sixteen plot experiments and ten on-farm experiments were conducted from 2014 to 2016 in Jiansanjiang Experiment Station of the China Agricultural University and Qixing Farm in Northeast China. Two mechanistic and three semi-empirical approaches using the sensor's default vegetation indices, normalized difference vegetation index and normalized difference red edge, were evaluated in comparison with the top performing vegetation indices selected from 51 tested indices. The results indicated that the most practical and stable method of using the RapidSCAN sensor for rice N status diagnosis is to calculate N sufficiency index with the default vegetation indices and then to estimate N nutrition index non-destructively (R 2  = 0.50-0.59). This semi-empirical approach achieved a diagnosis accuracy rate of 59-76%. The findings of this study will facilitate the application of the RapidSCAN active sensor for rice N status diagnosis across growth stages, cultivars and site-years, and thus contributing to precision N management for sustainable intensification of agriculture.

  8. Performance of a Fast Binary Readout CMOS Active Pixel Sensor Chip Designed for Charged Particle Detection

    Science.gov (United States)

    Deerli, Yavuz; Besanon, Marc; Besson, Auguste; Claus, Gilles; Deptuch, Grzegorz; Dulinski, Wojciech; Fourches, Nicolas; Goffe, Mathieu; Himmi, Abdelkader; Li, Yan; Lutz, Pierre; Orsini, Fabienne; Szelezniak, Michal

    2006-12-01

    We report on the performance of the MIMOSA8 (HiMAPS1) chip. The chip is a 128times32 pixels array where 24 columns have discriminated binary outputs and eight columns analog test outputs. Offset correction techniques are used extensively in this chip to overcome process related mismatches. The array is divided in four blocks of pixels with different conversion factors and is controlled by a serially programmable sequencer. MIMOSA8 is a representative of the CMOS sensors development option considered as a promising candidate for the Vertex Detector of the future International Linear Collider (ILC). The readout technique, implemented on the chip, combines high spatial resolution capabilities with high processing readout speed. Data acquisition, providing control of the chip and signal buffering and linked to a VME system, was made on the eight analog outputs. Analog data, without and with a 55Fe X-ray source, were acquired and processed using off-line analysis software. From the reconstruction of pixel clusters, built around a central pixel, we deduce that the charge spread is limited to the closest 25 pixels and almost all the available charge is collected. The position of the total charge collection peak (and subsequently the charge-to-voltage conversion factor) stays unaffected when the clock frequency is increased even up to 150 MHz (13.6 mus readout time per frame). The discriminators, placed in the readout chain, have proved to be fully functional. Beam tests have been made with high energy electrons at DESY (Germany) to study detection efficiency. The results prove that MIMOSA8 is the first and fastest successful monolithic active pixel sensor with on-chip signal discrimination for detection of MIPs

  9. Study protocol: Rehabilitation including Social and Physical activity and Education in Children and Teenagers with Cancer (RESPECT).

    Science.gov (United States)

    Thorsteinsson, Troels; Helms, Anne Sofie; Adamsen, Lis; Andersen, Lars Bo; Andersen, Karen Vitting; Christensen, Karl Bang; Hasle, Henrik; Heilmann, Carsten; Hejgaard, Nete; Johansen, Christoffer; Madsen, Marianne; Madsen, Svend Aage; Simovska, Venka; Strange, Birgit; Thing, Lone Friis; Wehner, Peder Skov; Schmiegelow, Kjeld; Larsen, Hanne Baekgaard

    2013-11-14

    During cancer treatment children have reduced contact with their social network of friends, and have limited participation in education, sports, and leisure activities. During and following cancer treatment, children describe school related problems, reduced physical fitness, and problems related to interaction with peers. The RESPECT study is a nationwide population-based prospective, controlled, mixed-methods intervention study looking at children aged 6-18 years newly diagnosed with cancer in eastern Denmark (n=120) and a matched control group in western Denmark (n=120). RESPECT includes Danish-speaking children diagnosed with cancer and treated at pediatric oncology units in Denmark. Primary endpoints are the level of educational achievement one year after the cessation of first-line cancer therapy, and the value of VO2max one year after the cessation of first-line cancer therapy. Secondary endpoints are quality of life measured by validated questionnaires and interviews, and physical performance. RESPECT includes a multimodal intervention program, including ambassador-facilitated educational, physical, and social interventions. The educational intervention includes an educational program aimed at the child with cancer, the child's schoolteachers and classmates, and the child's parents. Children with cancer will each have two ambassadors assigned from their class. The ambassadors visit the child with cancer at the hospital at alternating 2-week intervals and participate in the intervention program. The physical and social intervention examines the effect of early, structured, individualized, and continuous physical activity from diagnosis throughout the treatment period. The patients are tested at diagnosis, at 3 and 6 months after diagnosis, and one year after the cessation of treatment. The study is powered to quantify the impact of the combined educational, physical, and social intervention programs. RESPECT is the first population-based study to examine the

  10. Integrated active fire retrievals and biomass burning emissions using complementary near-coincident ground, airborne and spaceborne sensor data

    Science.gov (United States)

    Wilfrid Schroeder; Evan Ellicott; Charles Ichoku; Luke Ellison; Matthew B. Dickinson; Roger D. Ottmar; Craig Clements; Dianne Hall; Vincent Ambrosia; Robert. Kremens

    2013-01-01

    Ground, airborne and spaceborne data were collected for a 450 ha prescribed fire implemented on 18 October 2011 at the Henry W. Coe State Park in California. The integration of various data elements allowed near-coincident active fire retrievals to be estimated. The Autonomous Modular Sensor-Wildfire (AMS) airborne multispectral imaging system was used as a bridge...

  11. Applications of neutron activation analysis in determination of natural and man-made radionuclides, including PA-231

    Science.gov (United States)

    Byrne, A. R.; Benedik, L.

    1999-01-01

    Neutron activation analysis (NAA), being essentially an isotopic and not an elemental method of analysis, is capable of determining a number of important radionuclides of radioecological interest by transformation into another, more easily quantifiable radionuclide. The nuclear characteristics which favour this technique may be summarized in an advantage factor relative to radiometric analysis of the original radioanalyte. Well known or hardly known examples include235U,238U,232Th,230Th,129I,99Tc,237Np and231Pa; a number of these are discussed and illustrated in analysis of real samples of environmental and biological origin. In particular, determination of231Pa by RNAA was performed using both postirradiation and preseparation methods. Application of INAA to enable the use of238U and232Th as endogenous (internal) radiotracers in alpha spectrometric analyses of uranium and thorium radioisotopes in radioecological studies is described, also allowing independent data sets to be obtained for quality control.

  12. Active site of mycobacterial dUTPase: Structural characteristics and a built-in sensor

    International Nuclear Information System (INIS)

    Varga, Balazs; Barabas, Orsolya; Takacs, Eniko; Nagy, Nikolett; Nagy, Peter; Vertessy, Beata G.

    2008-01-01

    dUTPases are essential to eliminate dUTP for DNA integrity and provide dUMP for thymidylate biosynthesis. Mycobacterium tuberculosis apparently lacks any other thymidylate biosynthesis pathway, therefore dUTPase is a promising antituberculotic drug target. Crystal structure of the mycobacterial enzyme in complex with the isosteric substrate analog, α,β-imido-dUTP and Mg 2+ at 1.5 A resolution was determined that visualizes the full-length C-terminus, previously not localized. Interactions of a conserved motif important in catalysis, the Mycobacterium-specific five-residue-loop insert and C-terminal tetrapeptide could now be described in detail. Stacking of C-terminal histidine upon the uracil moiety prompted replacement with tryptophan. The resulting sensitive fluorescent sensor enables fast screening for binding of potential inhibitors to the active site. K d for α,β-imido-dUTP binding to mycobacterial dUTPase is determined to be 10-fold less than for human dUTPase, which is to be considered in drug optimization. A robust continuous activity assay for kinetic screening is proposed

  13. Atmospheric Chemistry Measurements in Schools and Outreach Activities with Low-cost Air Quality Sensors

    Science.gov (United States)

    Fleming, Z.; Monks, P. S.; McKenzie, K.

    2014-12-01

    The increasing range of low cost air quality sensors entering the market-place or being developed in-house in the last couple of years has led to many possibilities for using these instruments for public outreach activities or citizen science projects. A range of instruments sent out into local schools for the children to interpret and analyse the data and put the air quality in their area into context. A teaching package with tutorials has been developed to bring the data to life and link in with curriculum.The instruments have also been positioned around the city of Leicester in the UK to help understand the spatial variations in air quality and to assess the impact of retro-fitting buses on a busy bus route. The data is easily accessible online on a near real time basis and the various instruments can be compared with others around the country or the world from classrooms around the world.We will give an overview of the instrumentation with a comparison with commercial and cutting edge research instrumentation, the type of activities that were carried out and the public outreach forums where the data can be used.

  14. DNA-Catalytically Active Gold Nanoparticle Conjugates-Based Colorimetric Multidimensional Sensor Array for Protein Discrimination.

    Science.gov (United States)

    Wei, Xiangcong; Chen, Zhengbo; Tan, Lulu; Lou, Tianhong; Zhao, Yan

    2017-01-03

    A series of single-strand oligonucleotides functionalized catalytically active gold nanoparticle (AuNPs) as nonspecific receptors have been designed to build a protein sensing array. We take advantage of the correlation between the catalytic activity and the exposed surface area of AuNPs, i.e., DNA-proteins interactions mask the surface area of AuNPs, leading to poor catalytic performance of AuNPs. As the number of DNA-bound proteins increases, the surfaces of AuNPs become more masked; thus, the time of 4- nitrophenol/NaBH 4 reaction for color change (yellow → colorless) of the solution increases. Taking advantage of three nonspecific SH-labeled DNA sequences (A15, C15, and T15) as array sensing elements and the color-change time (CCT) of the solution as signal readout, colorimetric response patterns can be obtained on the array and identified via linear discriminant analysis (LDA). Eleven proteins have been completely distinguished with 100% accuracy with the naked eye at the 30 nM level. Remarkably, two similar proteins (bovine serum albumin and human serum albumin), two different proteins (bovine serum albumin and concanavalin) at the same concentration, and the mixtures of the two proteins with different molar ratios have been discriminated with 100%. The practicability of this sensor array is further validated by high accuracy (100%) identification of 11 proteins in human serum samples.

  15. Electrolocation of objects in fluids by means of active sensor movements based on discrete EEVs.

    Science.gov (United States)

    Wolf-Homeyer, Sabine; Engelmann, Jacob; Schneider, Axel

    2016-08-17

    Weakly electric fish use self-generated electric fields for communication and for active electrolocation. The sensor part of the biological system consists of a vast amount of electroreceptors which are distributed across the skin of the electric fish. Fish utilise changes of their position and body geometry to aid in the extraction of sensory information. Inspired by the biological model, this study looks for a fixed, minimal scanning strategy compiled of active receptor-system movements that allows unique identification of the positions of objects in the vicinity. The localisation method is based on the superposition of numerical extracted contour-rings of rotated and/or linearly shifted EEVs (Solberg et al 2008 Int. J. Rob. Res. 27 529-48), simulated by means of FEM. For the evaluation of a movement sequence, matrices of unique intersection points and respective contrast functions are introduced. The resultant optimal scanning strategy consists of a combination of a linear shift and a rotation of the original EEV.

  16. Implementation of Activity Sensor Equipment in the Homes of Chronic Obstructive Pulmonary Disease Patients.

    Science.gov (United States)

    Tillis, William; Bond, William F; Svendsen, Jessica; Guither, Sheila

    2017-11-01

    Telemedicine care models for managing advanced chronic obstructive pulmonary disease (COPD) may benefit from the addition of motion sensing, spirometry, and tablet-based symptom diary tracking. We conducted a feasibility study of telemedicine in the home setting using multiple activity sensor monitoring equipment. Deployment and monitoring were supported by home health nurses with technical advice from the equipment makers as needed. Data analytics for motion sensing was provided by the research sponsor, but was not used for care decisions. On study intake, a health risk assessment, Quality of Life (SF-36) survey, and the St. George Respiratory Questionnaire were administered to assess patients' self-perception of quality of life, activities of daily life function, and difficulty living with COPD. Twenty-eight patients were enrolled and data were gathered for a minimum of 6 months and maximum of 9 months. The researchers demonstrated that augmentation of traditional telemedicine methods with motion sensing, spirometry, and symptom diaries appears feasible. The technical, process, logistics barriers, and solutions required for system deployment are described. The researchers demonstrated that augmentation of traditional telemedicine methods with motion sensing, spirometry, and symptom diaries appears feasible. Further exploration will be needed to determine the value of this information in preventing outcomes relevant to patients.

  17. Cross-Layer Active Predictive Congestion Control Protocol for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Yinfeng Wu

    2009-10-01

    Full Text Available In wireless sensor networks (WSNs, there are numerous factors that may cause network congestion problems, such as the many-to-one communication modes, mutual interference of wireless links, dynamic changes of network topology and the memory-restrained characteristics of nodes. All these factors result in a network being more vulnerable to congestion. In this paper, a cross-layer active predictive congestion control scheme (CL-APCC for improving the performance of networks is proposed. Queuing theory is applied in the CL-APCC to analyze data flows of a single-node according to its memory status, combined with the analysis of the average occupied memory size of local networks. It also analyzes the current data change trends of local networks to forecast and actively adjust the sending rate of the node in the next period. In order to ensure the fairness and timeliness of the network, the IEEE 802.11 protocol is revised based on waiting time, the number of the node‟s neighbors and the original priority of data packets, which dynamically adjusts the sending priority of the node. The performance of CL-APCC, which is evaluated by extensive simulation experiments. is more efficient in solving the congestion in WSNs. Furthermore, it is clear that the proposed scheme has an outstanding advantage in terms of improving the fairness and lifetime of networks.

  18. Cross-layer active predictive congestion control protocol for wireless sensor networks.

    Science.gov (United States)

    Wan, Jiangwen; Xu, Xiaofeng; Feng, Renjian; Wu, Yinfeng

    2009-01-01

    In wireless sensor networks (WSNs), there are numerous factors that may cause network congestion problems, such as the many-to-one communication modes, mutual interference of wireless links, dynamic changes of network topology and the memory-restrained characteristics of nodes. All these factors result in a network being more vulnerable to congestion. In this paper, a cross-layer active predictive congestion control scheme (CL-APCC) for improving the performance of networks is proposed. Queuing theory is applied in the CL-APCC to analyze data flows of a single-node according to its memory status, combined with the analysis of the average occupied memory size of local networks. It also analyzes the current data change trends of local networks to forecast and actively adjust the sending rate of the node in the next period. In order to ensure the fairness and timeliness of the network, the IEEE 802.11 protocol is revised based on waiting time, the number of the node's neighbors and the original priority of data packets, which dynamically adjusts the sending priority of the node. The performance of CL-APCC, which is evaluated by extensive simulation experiments. is more efficient in solving the congestion in WSNs. Furthermore, it is clear that the proposed scheme has an outstanding advantage in terms of improving the fairness and lifetime of networks.

  19. 14C autoradiography with a novel wafer scale CMOS Active Pixel Sensor

    International Nuclear Information System (INIS)

    Esposito, M; Wells, K; Anaxagoras, T; Allinson, N M; Larner, J

    2013-01-01

    14 C autoradiography is a well established technique for structural and metabolic analysis of cells and tissues. The most common detection medium for this application is film emulsion, which offers unbeatable spatial resolution due to its fine granularity but at the same time has some limiting drawbacks such as poor linearity and rapid saturation. In recent years several digital detectors have been developed, following the technological transition from analog to digital-based detection systems in the medical and biological field. Even so such digital systems have been greatly limited by the size of their active area (a few square centimeters), which have made them unsuitable for routine use in many biological applications where sample areas are typically ∼ 10–100 cm 2 . The Multidimensional Integrated Intelligent Imaging (MI3-Plus) consortium has recently developed a new large area CMOS Active Pixel Sensor (12.8 cm × 13.1 cm). This detector, based on the use of two different pixel resolutions, is capable of providing simultaneously low noise and high dynamic range on a wafer scale. In this paper we will demonstrate the suitability of this detector for routine beta autoradiography in a comparative approach with widely used film emulsion.

  20. Online Sensor Calibration Assessment in Nuclear Power Systems

    International Nuclear Information System (INIS)

    Coble, Jamie B.; Ramuhalli, Pradeep; Meyer, Ryan M.; Hashemian, Hash

    2013-01-01

    Safe, efficient, and economic operation of nuclear systems (nuclear power plants, fuel fabrication and storage, used fuel processing, etc.) relies on transmission of accurate and reliable measurements. During operation, sensors degrade due to age, environmental exposure, and maintenance interventions. Sensor degradation can affect the measured and transmitted signals, including sensor failure, signal drift, sensor response time, etc. Currently, periodic sensor recalibration is performed to avoid these problems. Sensor recalibration activities include both calibration assessment and adjustment (if necessary). In nuclear power plants, periodic recalibration of safety-related sensors is required by the plant technical specifications. Recalibration typically occurs during refueling outages (about every 18 to 24 months). Non-safety-related sensors also undergo recalibration, though not as frequently. However, this approach to maintaining sensor calibration and performance is time-consuming and expensive, leading to unnecessary maintenance, increased radiation exposure to maintenance personnel, and potential damage to sensors. Online monitoring (OLM) of sensor performance is a non-invasive approach to assess instrument calibration. OLM can mitigate many of the limitations of the current periodic recalibration practice by providing more frequent assessment of calibration and identifying those sensors that are operating outside of calibration tolerance limits without removing sensors or interrupting operation. This can support extended operating intervals for unfaulted sensors and target recalibration efforts to only degraded sensors

  1. Real-time method for establishing a detection map for a network of sensors

    Science.gov (United States)

    Nguyen, Hung D; Koch, Mark W; Giron, Casey; Rondeau, Daniel M; Russell, John L

    2012-09-11

    A method for establishing a detection map of a dynamically configurable sensor network. This method determines an appropriate set of locations for a plurality of sensor units of a sensor network and establishes a detection map for the network of sensors while the network is being set up; the detection map includes the effects of the local terrain and individual sensor performance. Sensor performance is characterized during the placement of the sensor units, which enables dynamic adjustment or reconfiguration of the placement of individual elements of the sensor network during network set-up to accommodate variations in local terrain and individual sensor performance. The reconfiguration of the network during initial set-up to accommodate deviations from idealized individual sensor detection zones improves the effectiveness of the sensor network in detecting activities at a detection perimeter and can provide the desired sensor coverage of an area while minimizing unintentional gaps in coverage.

  2. Radiation effects on active pixel sensors (APS); Effets de l'irradiation sur les capteurs a pixels actifs (APS)

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, M.; David, J.P. [ONERA-CERT/, 31 - Toulouse (France)

    1999-07-01

    Active pixel sensor (APS) is a new generation of image sensors which presents several advantages relatively to charge coupled devices (CCDs) particularly for space applications (APS requires only 1 voltage to operate which reduces considerably current consumption). Irradiation was performed using {sup 60}Co gamma radiation at room temperature and at a dose rate of 150 Gy(Si)/h. 2 types of APS have been tested: photodiode-APS and photoMOS-APS. The results show that photoMOS-APS is more sensitive to radiation effects than photodiode-APS. Important parameters of image sensors like dark currents increase sharply with dose levels. Nevertheless photodiode-APS sensitivity is one hundred time lower than photoMOS-APS sensitivity.

  3. Radiation effects on active pixel sensors (APS); Effets de l'irradiation sur les capteurs a pixels actifs (APS)

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, M; David, J P [ONERA-CERT/, 31 - Toulouse (France)

    1999-07-01

    Active pixel sensor (APS) is a new generation of image sensors which presents several advantages relatively to charge coupled devices (CCDs) particularly for space applications (APS requires only 1 voltage to operate which reduces considerably current consumption). Irradiation was performed using {sup 60}Co gamma radiation at room temperature and at a dose rate of 150 Gy(Si)/h. 2 types of APS have been tested: photodiode-APS and photoMOS-APS. The results show that photoMOS-APS is more sensitive to radiation effects than photodiode-APS. Important parameters of image sensors like dark currents increase sharply with dose levels. Nevertheless photodiode-APS sensitivity is one hundred time lower than photoMOS-APS sensitivity.

  4. Accuracy of a Custom Physical Activity and Knee Angle Measurement Sensor System for Patients with Neuromuscular Disorders and Gait Abnormalities

    Directory of Open Access Journals (Sweden)

    Frank Feldhege

    2015-05-01

    Full Text Available Long-term assessment of ambulatory behavior and joint motion are valuable tools for the evaluation of therapy effectiveness in patients with neuromuscular disorders and gait abnormalities. Even though there are several tools available to quantify ambulatory behavior in a home environment, reliable measurement of joint motion is still limited to laboratory tests. The aim of this study was to develop and evaluate a novel inertial sensor system for ambulatory behavior and joint motion measurement in the everyday environment. An algorithm for behavior classification, step detection, and knee angle calculation was developed. The validation protocol consisted of simulated daily activities in a laboratory environment. The tests were performed with ten healthy subjects and eleven patients with multiple sclerosis. Activity classification showed comparable performance to commercially available activPAL sensors. Step detection with our sensor system was more accurate. The calculated flexion-extension angle of the knee joint showed a root mean square error of less than 5° compared with results obtained using an electro-mechanical goniometer. This new system combines ambulatory behavior assessment and knee angle measurement for long-term measurement periods in a home environment. The wearable sensor system demonstrated high validity for behavior classification and knee joint angle measurement in a laboratory setting.

  5. Active Pixel Sensors in ams H18/H35 HV-CMOS Technology for the ATLAS HL-LHC Upgrade

    CERN Document Server

    Ristic, Branislav

    2016-09-21

    Deep sub micron HV-CMOS processes offer the opportunity for sensors built by industry standard techniques while being HV tolerant, making them good candidates for drift-based, fast collecting, thus radiation-hard pixel detectors. For the upgrade of the ATLAS Pixel Detector towards the HL-LHC requirements, active pixel sensors in HV-CMOS technology were investigated. These implement amplifier and discriminator stages directly in insulating deep n-wells, which also act as collecting electrodes. The deep n-wells allow for bias voltages up to 150V leading to a depletion depth of several 10um. Prototype sensors in the ams H18 180nm and H35 350nm HV-CMOS processes have been manufactured, acting as a potential drop-in replacement for the current ATLAS Pixel sensors, thus leaving higher level processing such as trigger handling to dedicated read-out chips. Sensors were thoroughly tested in lab measurements as well as in testbeam experiments. Irradiation with X-rays and protons revealed a tolerance to ionizing doses o...

  6. Integrating wireless sensor networks with CE devices for health care activity tracking in the home environment

    NARCIS (Netherlands)

    Bosman, R.P.; Lukkien, J.J.; Verhoeven, R.

    2009-01-01

    Wireless sensing devices containing limited processing and communication capabilities are becoming available for all sorts of purposes. An important problem is to integrate networks of these sensors with the existing CE en IT infrastructure such that a) data coming out of the sensor network can be

  7. Active Satellite Sensors for the needs of Cultural Heritage: Introducing SAR applications in Cyprus through ATHENA project

    Science.gov (United States)

    Kouhartsiouk, Demetris; Agapiou, Athos; Lynsadrou, Vasiliki; Themistocleous, Kyriacos; Nisantzi, Argyro; Hadjimitsis, Diofantos G.; Lasaponara, Rosa; Masini, Nicola; Brcic, Ramon; Eineder, Michael; Krauss, Thomas; Cerra, Daniele; Gessner, Ursula; Schreier, Gunter

    2017-04-01

    Non-invasive landscape investigation for archaeological purposes includes a wide range of survey techniques, most of which include in-situ methods. In the recent years, a major advance in the non-invasive surveying techniques has been the introduction of active remote sensing technologies. One of such technologies is spaceborne radar, known as Synthetic Aperture Radar (SAR). SAR has proven to be a valuable tool in the analysis of potential archaeological marks and in the systematic cultural heritage site monitoring. With the use of SAR, it is possible to monitor slight variations in vegetation and soil often interpreted as archaeological signs, while radar sensors frequently having penetrating capabilities offering an insight into shallow underground remains. Radar remote sensing for immovable cultural heritage and archaeological applications has been recently introduced to Cyprus through the currently ongoing ATHENA project. ATHENA project, under the Horizon 2020 programme, aims at building a bridge between research institutions of the low performing Member States and internationally-leading counterparts at EU level, mainly through training workshops and a series of knowledge transfer activities, frequently taking place on the basis of capacity development. The project is formed as the consortium of the Remote Sensing and Geo-Environment Research Laboratory of the Cyprus University of Technology (CUT), the National Research Council of Italy (CNR) and the German Aerospace Centre (DLR). As part of the project, a number of cultural heritage sites in Cyprus have been studied testing different methodologies involving SAR imagery such as Amplitude Change Detection, Coherence Calculation and fusion techniques. The ATHENA's prospective agenda includes the continuation of the capacity building programme with upcoming training workshops to take place while expanding the knowledge of radar applications on conservation and risk monitoring of cultural heritage sites through

  8. A New Generation of FRET Sensors for Robust Measurement of Gαi1, Gαi2 and Gαi3 Activation Kinetics in Single Cells.

    Directory of Open Access Journals (Sweden)

    Jakobus van Unen

    Full Text Available G-protein coupled receptors (GPCRs can activate a heterotrimeric G-protein complex with subsecond kinetics. Genetically encoded biosensors based on Förster resonance energy transfer (FRET are ideally suited for the study of such fast signaling events in single living cells. Here we report on the construction and characterization of three FRET biosensors for the measurement of Gαi1, Gαi2 and Gαi3 activation. To enable quantitative long-term imaging of FRET biosensors with high dynamic range, fluorescent proteins with enhanced photophysical properties are required. Therefore, we use the currently brightest and most photostable CFP variant, mTurquoise2, as donor fused to Gαi subunit, and cp173Venus fused to the Gγ2 subunit as acceptor. The Gαi FRET biosensors constructs are expressed together with Gβ1 from a single plasmid, providing preferred relative expression levels with reduced variation in mammalian cells. The Gαi FRET sensors showed a robust response to activation of endogenous or over-expressed alpha-2A-adrenergic receptors, which was inhibited by pertussis toxin. Moreover, we observed activation of the Gαi FRET sensor in single cells upon stimulation of several GPCRs, including the LPA2, M3 and BK2 receptor. Furthermore, we show that the sensors are well suited to extract kinetic parameters from fast measurements in the millisecond time range. This new generation of FRET biosensors for Gαi1, Gαi2 and Gαi3 activation will be valuable for live-cell measurements that probe Gαi activation.

  9. CMOS Image Sensors: Electronic Camera On A Chip

    Science.gov (United States)

    Fossum, E. R.

    1995-01-01

    Recent advancements in CMOS image sensor technology are reviewed, including both passive pixel sensors and active pixel sensors. On- chip analog to digital converters and on-chip timing and control circuits permit realization of an electronic camera-on-a-chip. Highly miniaturized imaging systems based on CMOS image sensor technology are emerging as a competitor to charge-coupled devices for low cost uses.

  10. Automotive sensors

    Science.gov (United States)

    Marek, Jiri; Illing, Matthias

    2003-01-01

    Sensors are an essential component of most electronic systems in the car. They deliver input parameters for comfort features, engine and emission control as well as for the active and passive safety systems. New technologies such as silicon micromachining play an important role for the introduction of these sensors in all vehicle classes. The importance and use of these sensor technologies in today"s automotive applications will be shown in this article. Finally an outlook on important current developments and new functions in the car will be given.

  11. SSTAC/ARTS review of the draft Integrated Technology Plan (ITP). Volume 8: Aerothermodynamics Automation and Robotics (A/R) systems sensors, high-temperature superconductivity

    Science.gov (United States)

    1991-01-01

    Viewgraphs of briefings presented at the SSTAC/ARTS review of the draft Integrated Technology Plan (ITP) on aerothermodynamics, automation and robotics systems, sensors, and high-temperature superconductivity are included. Topics covered include: aerothermodynamics; aerobraking; aeroassist flight experiment; entry technology for probes and penetrators; automation and robotics; artificial intelligence; NASA telerobotics program; planetary rover program; science sensor technology; direct detector; submillimeter sensors; laser sensors; passive microwave sensing; active microwave sensing; sensor electronics; sensor optics; coolers and cryogenics; and high temperature superconductivity.

  12. SSTAC/ARTS review of the draft Integrated Technology Plan (ITP). Volume 8: Aerothermodynamics Automation and Robotics (A/R) systems sensors, high-temperature superconductivity

    International Nuclear Information System (INIS)

    1991-06-01

    Viewgraphs of briefings presented at the SSTAC/ARTS review of the draft Integrated Technology Plan (ITP) on aerothermodynamics, automation and robotics systems, sensors, and high-temperature superconductivity are included. Topics covered include: aerothermodynamics; aerobraking; aeroassist flight experiment; entry technology for probes and penetrators; automation and robotics; artificial intelligence; NASA telerobotics program; planetary rover program; science sensor technology; direct detector; submillimeter sensors; laser sensors; passive microwave sensing; active microwave sensing; sensor electronics; sensor optics; coolers and cryogenics; and high temperature superconductivity

  13. Energy Efficient Routing and Node Activity Scheduling in the OCARI Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Saoucene Mahfoudh

    2010-08-01

    Full Text Available Sensor nodes are characterized by a small size, a low cost, an advanced communication technology, but also a limited amount of energy. Energy efficient strategies are required in such networks to maximize network lifetime. In this paper, we focus on a solution integrating energy efficient routing and node activity scheduling. The energy efficient routing we propose, called EOLSR, selects the route and minimizes the energy consumed by an end-to-end transmission, while avoiding nodes with low residual energy. Simulation results show that EOLSR outperforms the solution selecting the route of minimum energy as well as the solution based on node residual energy. Cross-layering allows EOLSR to use information from the application layer or the MAC layer to reduce its overhead and increase network lifetime. Node activity scheduling is based on the following observation: the sleep state is the least power consuming state. So, to schedule node active and sleeping periods, we propose SERENA that colors all network nodes using a small number of colors, such that two nodes with the same color can transmit without interfering. The node color is mapped into a time slot during which the node can transmit. Consequently, each node is awake during its slot and the slots of its one-hop neighbors, and sleeps in the remaining time. We evaluate SERENA benefits obtained in terms of bandwidth, delay and energy. We also show how cross-layering with the application layer can improve the end-to-end delays for data gathering applications.

  14. Antimicrobial Active Packaging including Chitosan Films with Thymus vulgaris L. Essential Oil for Ready-to-Eat Meat

    Directory of Open Access Journals (Sweden)

    Jesús Quesada

    2016-08-01

    Full Text Available An active packaging system has been designed for the shelf life extension of ready to eat meat products. The package included an inner surface coated with a chitosan film with thyme essential oil (0%, 0.5%, 1%, and 2% not in direct contact with the meat. Our aim was to reduce the impact of thyme essential oil (EO on meat sensory properties by using a chemotype with low odor intensity. The pH, color parameters, microbial populations, and sensory properties were assessed during 4 weeks of refrigerated storage. The presence of EO films reduced yeast populations, whereas aerobic mesophilic bacteria, lactic acid bacteria, and enterobacteria were not affected by the presence of the EO in the films. Meat color preservation (a * was enhanced in the presence of EO, giving a better appearance to the packaged meat. The presence of the chitosan-EO layer reduced water condensation inside the package, whereas packages containing only chitosan had evident water droplets. Thyme odor was perceived as desirable in cooked meat, and the typical product odor intensity decreased by increasing the EO concentration. Further studies should point towards developing oil blends or combinations with natural antimicrobial agents to be incorporated into the film to improve its antimicrobial properties.

  15. A single parameter representation of hygroscopic growth and cloud condensation nucleus activity – Part 2: Including solubility

    Directory of Open Access Journals (Sweden)

    M. D. Petters

    2008-10-01

    Full Text Available The ability of a particle to serve as a cloud condensation nucleus in the atmosphere is determined by its size, hygroscopicity and its solubility in water. Usually size and hygroscopicity alone are sufficient to predict CCN activity. Single parameter representations for hygroscopicity have been shown to successfully model complex, multicomponent particles types. Under the assumption of either complete solubility, or complete insolubility of a component, it is not necessary to explicitly include that component's solubility into the single parameter framework. This is not the case if sparingly soluble materials are present. In this work we explicitly account for solubility by modifying the single parameter equations. We demonstrate that sensitivity to the actual value of solubility emerges only in the regime of 2×10−1–5×10−4, where the solubility values are expressed as volume of solute per unit volume of water present in a saturated solution. Compounds that do not fall inside this sparingly soluble envelope can be adequately modeled assuming they are either infinitely soluble in water or completely insoluble.

  16. Human Activity Recognition from Smart-Phone Sensor Data using a Multi-Class Ensemble Learning in Home Monitoring.

    Science.gov (United States)

    Ghose, Soumya; Mitra, Jhimli; Karunanithi, Mohan; Dowling, Jason

    2015-01-01

    Home monitoring of chronically ill or elderly patient can reduce frequent hospitalisations and hence provide improved quality of care at a reduced cost to the community, therefore reducing the burden on the healthcare system. Activity recognition of such patients is of high importance in such a design. In this work, a system for automatic human physical activity recognition from smart-phone inertial sensors data is proposed. An ensemble of decision trees framework is adopted to train and predict the multi-class human activity system. A comparison of our proposed method with a multi-class traditional support vector machine shows significant improvement in activity recognition accuracies.

  17. Nitrophenol chemi-sensor and active solar photocatalyst based on spinel hetaerolite nanoparticles.

    Science.gov (United States)

    Khan, Sher Bahadar; Rahman, Mohammed M; Akhtar, Kalsoom; Asiri, Abdullah M; Rub, Malik Abdul

    2014-01-01

    In this contribution, a significant catalyst based on spinel ZnMn2O4 composite nanoparticles has been developed for electro-catalysis of nitrophenol and photo-catalysis of brilliant cresyl blue. ZnMn2O4 composite (hetaerolite) nanoparticles were prepared by easy low temperature hydrothermal procedure and structurally characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) and UV-visible spectroscopy which illustrate that the prepared material is optical active and composed of well crystalline body-centered tetragonal nanoparticles with average size of ∼ 38 ± 10 nm. Hetaerolite nanoparticles were applied for the advancement of a nitrophenol sensor which exhibited high sensitivity (1.500 µAcm(-2) mM(-1)), stability, repeatability and lower limit of detection (20.0 µM) in short response time (10 sec). Moreover, hetaerolite nanoparticles executed high solar photo-catalytic degradation when applied to brilliant cresyl blue under visible light.

  18. Pitch dependence of the tolerance of CMOS monolithic active pixel sensors to non-ionizing radiation

    International Nuclear Information System (INIS)

    Doering, D.; Deveaux, M.; Domachowski, M.; Fröhlich, I.; Koziel, M.; Müntz, C.; Scharrer, P.; Stroth, J.

    2013-01-01

    CMOS monolithic active pixel sensors (MAPS) have demonstrated excellent performance as tracking detectors for charged particles. They provide an outstanding spatial resolution (a few μm), a detection efficiency of ≳99.9%, very low material budget (0.05%X 0 ) and good radiation tolerance (≳1Mrad, ≳10 13 n eq /cm 2 ) (Deveaux et al. [1]). This makes them an interesting technology for various applications in heavy ion and particle physics. Their tolerance to bulk damage was recently improved by using high-resistivity (∼1kΩcm) epitaxial layers as sensitive volume (Deveaux et al. [1], Dorokhov et al. [2]). The radiation tolerance of conventional MAPS is known to depend on the pixel pitch. This is as a higher pitch extends the distance, which signal electrons have to travel by thermal diffusion before being collected. Increased diffusion paths turn into a higher probability of loosing signal charge due to recombination. Provided that a similar effect exists in MAPS with high-resistivity epitaxial layer, it could be used to extend their radiation tolerance further. We addressed this question with MIMOSA-18AHR prototypes, which were provided by the IPHC Strasbourg and irradiated with reactor neutrons. We report about the results of this study and provide evidences that MAPS with 10μm pixel pitch tolerate doses of ≳3×10 14 n eq /cm 2

  19. Comparison of Feature Learning Methods for Human Activity Recognition Using Wearable Sensors

    Directory of Open Access Journals (Sweden)

    Frédéric Li

    2018-02-01

    Full Text Available Getting a good feature representation of data is paramount for Human Activity Recognition (HAR using wearable sensors. An increasing number of feature learning approaches—in particular deep-learning based—have been proposed to extract an effective feature representation by analyzing large amounts of data. However, getting an objective interpretation of their performances faces two problems: the lack of a baseline evaluation setup, which makes a strict comparison between them impossible, and the insufficiency of implementation details, which can hinder their use. In this paper, we attempt to address both issues: we firstly propose an evaluation framework allowing a rigorous comparison of features extracted by different methods, and use it to carry out extensive experiments with state-of-the-art feature learning approaches. We then provide all the codes and implementation details to make both the reproduction of the results reported in this paper and the re-use of our framework easier for other researchers. Our studies carried out on the OPPORTUNITY and UniMiB-SHAR datasets highlight the effectiveness of hybrid deep-learning architectures involving convolutional and Long-Short-Term-Memory (LSTM to obtain features characterising both short- and long-term time dependencies in the data.

  20. Comparison of Feature Learning Methods for Human Activity Recognition Using Wearable Sensors.

    Science.gov (United States)

    Li, Frédéric; Shirahama, Kimiaki; Nisar, Muhammad Adeel; Köping, Lukas; Grzegorzek, Marcin

    2018-02-24

    Getting a good feature representation of data is paramount for Human Activity Recognition (HAR) using wearable sensors. An increasing number of feature learning approaches-in particular deep-learning based-have been proposed to extract an effective feature representation by analyzing large amounts of data. However, getting an objective interpretation of their performances faces two problems: the lack of a baseline evaluation setup, which makes a strict comparison between them impossible, and the insufficiency of implementation details, which can hinder their use. In this paper, we attempt to address both issues: we firstly propose an evaluation framework allowing a rigorous comparison of features extracted by different methods, and use it to carry out extensive experiments with state-of-the-art feature learning approaches. We then provide all the codes and implementation details to make both the reproduction of the results reported in this paper and the re-use of our framework easier for other researchers. Our studies carried out on the OPPORTUNITY and UniMiB-SHAR datasets highlight the effectiveness of hybrid deep-learning architectures involving convolutional and Long-Short-Term-Memory (LSTM) to obtain features characterising both short- and long-term time dependencies in the data.

  1. Second-Generation Thermal Neutron Activation Sensor for Confirmatory Land-Mine Detection

    International Nuclear Information System (INIS)

    Edward Clifford; Harry Ing; John McFee; H. Robert Andrews; Tom Cousins

    2000-01-01

    This paper describes the development of the Improved Land-Mine Detector System (ILDS), a vehicle-mounted nonmetallic land-mine detector. The ILDS consists of a custom teleoperated vehicle carrying an infrared imager, an electromagnetic induction detector, and a ground probing radar-which scan the ground in front of the vehicle. Custom navigation and data fusion software combine information from scanning sensors and navigation systems to detect and automatically track suspect targets until the confirmation detector at the rear of the system is positioned to within 30 cm of the target location. The confirmation detector, using thermal neutron activation (TNA) to detect bulk nitrogen in explosives, then dwells over the target for 10 to 120 s. In U.S. government tests (summer 1998), the ILDS advanced development model (ADM) placed first or second out of five competitors on every test. The construction of the second-generation TNA detector and preliminary testing should be complete by March 2000. Testing on real mines is expected to start in summer 2000

  2. CMOS Active Pixel Sensors as energy-range detectors for proton Computed Tomography

    International Nuclear Information System (INIS)

    Esposito, M.; Waltham, C.; Allinson, N.M.; Anaxagoras, T.; Evans, P.M.; Poludniowski, G.; Green, S.; Parker, D.J.; Price, T.; Manolopoulos, S.; Nieto-Camero, J.

    2015-01-01

    Since the first proof of concept in the early 70s, a number of technologies has been proposed to perform proton CT (pCT), as a means of mapping tissue stopping power for accurate treatment planning in proton therapy. Previous prototypes of energy-range detectors for pCT have been mainly based on the use of scintillator-based calorimeters, to measure proton residual energy after passing through the patient. However, such an approach is limited by the need for only a single proton passing through the energy-range detector in a read-out cycle. A novel approach to this problem could be the use of pixelated detectors, where the independent read-out of each pixel allows to measure simultaneously the residual energy of a number of protons in the same read-out cycle, facilitating a faster and more efficient pCT scan. This paper investigates the suitability of CMOS Active Pixel Sensors (APSs) to track individual protons as they go through a number of CMOS layers, forming an energy-range telescope. Measurements performed at the iThemba Laboratories will be presented and analysed in terms of correlation, to confirm capability of proton tracking for CMOS APSs

  3. CMOS Active Pixel Sensors as energy-range detectors for proton Computed Tomography.

    Science.gov (United States)

    Esposito, M; Anaxagoras, T; Evans, P M; Green, S; Manolopoulos, S; Nieto-Camero, J; Parker, D J; Poludniowski, G; Price, T; Waltham, C; Allinson, N M

    2015-06-03

    Since the first proof of concept in the early 70s, a number of technologies has been proposed to perform proton CT (pCT), as a means of mapping tissue stopping power for accurate treatment planning in proton therapy. Previous prototypes of energy-range detectors for pCT have been mainly based on the use of scintillator-based calorimeters, to measure proton residual energy after passing through the patient. However, such an approach is limited by the need for only a single proton passing through the energy-range detector in a read-out cycle. A novel approach to this problem could be the use of pixelated detectors, where the independent read-out of each pixel allows to measure simultaneously the residual energy of a number of protons in the same read-out cycle, facilitating a faster and more efficient pCT scan. This paper investigates the suitability of CMOS Active Pixel Sensors (APSs) to track individual protons as they go through a number of CMOS layers, forming an energy-range telescope. Measurements performed at the iThemba Laboratories will be presented and analysed in terms of correlation, to confirm capability of proton tracking for CMOS APSs.

  4. Design of an osmotic pressure sensor for sensing an osmotically active substance

    International Nuclear Information System (INIS)

    Ch, Nagesh; Paily, Roy P

    2015-01-01

    A pressure sensor based on the osmosis principle has been designed and demonstrated successfully for the sensing of the concentration levels of an osmotically active substance. The device is fabricated using the bulk micro-machining technique on a silicon on insulator (SOI) substrate. The substrate has a square cavity on the bottom side to fill with the reference glucose solution and a silicon (Si) membrane on the top side for the actuation. Two sets of devices, having membrane thicknesses of 10 µm and 25 µm, but the same area of 3 mm ×3 mm, are fabricated. The cavity is filled with a glucose solution of 100 mg dL −1 and it is sealed with a semi-permeable membrane made up of cellulose acetate material. The glucose solution is employed to prove the functionality of the device and it is tested for different glucose concentration levels, ranging from 50 mg dL −1 to 450 mg dL −1 . The output voltage obtained for the corresponding glucose concentration levels ranges from −6.7 mV to 22.7 mV for the 10 µm device and from −1.7 mV to 4 mV for the 25 µm device. The device operation was simulated using the finite element method (FEM) and the finite volume method (FVM), and the simulation and experimental results match closely. A response time of 40 min is obtained in the case of the 10 µm device compared to one of 30 min for the 25 µm device. The response times obtained for these devices are found to be small compared to those in similar works based on the osmosis principle. This pressure sensor has the potential to provide controlled drug delivery if it can be integrated with other microfluidic devices. (paper)

  5. Using hierarchical clustering methods to classify motor activities of COPD patients from wearable sensor data

    Directory of Open Access Journals (Sweden)

    Reilly John J

    2005-06-01

    Full Text Available Abstract Background Advances in miniature sensor technology have led to the development of wearable systems that allow one to monitor motor activities in the field. A variety of classifiers have been proposed in the past, but little has been done toward developing systematic approaches to assess the feasibility of discriminating the motor tasks of interest and to guide the choice of the classifier architecture. Methods A technique is introduced to address this problem according to a hierarchical framework and its use is demonstrated for the application of detecting motor activities in patients with chronic obstructive pulmonary disease (COPD undergoing pulmonary rehabilitation. Accelerometers were used to collect data for 10 different classes of activity. Features were extracted to capture essential properties of the data set and reduce the dimensionality of the problem at hand. Cluster measures were utilized to find natural groupings in the data set and then construct a hierarchy of the relationships between clusters to guide the process of merging clusters that are too similar to distinguish reliably. It provides a means to assess whether the benefits of merging for performance of a classifier outweigh the loss of resolution incurred through merging. Results Analysis of the COPD data set demonstrated that motor tasks related to ambulation can be reliably discriminated from tasks performed in a seated position with the legs in motion or stationary using two features derived from one accelerometer. Classifying motor tasks within the category of activities related to ambulation requires more advanced techniques. While in certain cases all the tasks could be accurately classified, in others merging clusters associated with different motor tasks was necessary. When merging clusters, it was found that the proposed method could lead to more than 12% improvement in classifier accuracy while retaining resolution of 4 tasks. Conclusion Hierarchical

  6. An Autonomous Sensor System Architecture for Active Flow and Noise Control Feedback

    Science.gov (United States)

    Humphreys, William M, Jr.; Culliton, William G.

    2008-01-01

    Multi-channel sensor fusion represents a powerful technique to simply and efficiently extract information from complex phenomena. While the technique has traditionally been used for military target tracking and situational awareness, a study has been successfully completed that demonstrates that sensor fusion can be applied equally well to aerodynamic applications. A prototype autonomous hardware processor was successfully designed and used to detect in real-time the two-dimensional flow reattachment location generated by a simple separated-flow wind tunnel model. The success of this demonstration illustrates the feasibility of using autonomous sensor processing architectures to enhance flow control feedback signal generation.

  7. Wireless sensor

    Science.gov (United States)

    Lamberti, Vincent E.; Howell, JR, Layton N.; Mee, David K.; Sepaniak, Michael J.

    2016-02-09

    Disclosed is a sensor for detecting a target material. The sensor includes a ferromagnetic metal and a molecular recognition reagent coupled to the ferromagnetic metal. The molecular recognition reagent is operable to expand upon exposure to vapor or liquid from the target material such that the molecular recognition reagent changes a tensile stress upon the ferromagnetic metal. The target material is detected based on changes in the magnetic switching characteristics of the ferromagnetic metal caused by the changes in the tensile stress.

  8. Film-based Sensors with Piezoresistive Molecular Conductors as Active Components Strain Damage and Thermal Regeneration

    Directory of Open Access Journals (Sweden)

    Elena Laukhina

    2011-02-01

    Full Text Available The article is addressed to the development of flexible all-organic bi layer (BL film-based sensors being capable of measuring strain as a well-defined electrical signal in a wide range of elongations and temperature. The purpose was achieved by covering polycarbonate films with the polycrystalline layer of a high piezoresistive organic molecular conductor. To determine restrictions for sensor applications, the effect of monoaxial strain on the resistance and texture of the sensing layers of BL films was studied. The experiments have shown that the maximum strain before fracture is about 1 %. A thermal regeneration of the sensing layer of the BL film-based sensors that were damaged by cyclic load is also described. These sensors are able to take the place of conventional metal-based strain and pressure gages in low cost innovative controlling and monitoring technologies.

  9. A Physical Activity Reference Data-Set Recorded from Older Adults Using Body-Worn Inertial Sensors and Video Technology—The ADAPT Study Data-Set

    Directory of Open Access Journals (Sweden)

    Alan Kevin Bourke

    2017-03-01

    Full Text Available Physical activity monitoring algorithms are often developed using conditions that do not represent real-life activities, not developed using the target population, or not labelled to a high enough resolution to capture the true detail of human movement. We have designed a semi-structured supervised laboratory-based activity protocol and an unsupervised free-living activity protocol and recorded 20 older adults performing both protocols while wearing up to 12 body-worn sensors. Subjects’ movements were recorded using synchronised cameras (≥25 fps, both deployed in a laboratory environment to capture the in-lab portion of the protocol and a body-worn camera for out-of-lab activities. Video labelling of the subjects’ movements was performed by five raters using 11 different category labels. The overall level of agreement was high (percentage of agreement >90.05%, and Cohen’s Kappa, corrected kappa, Krippendorff’s alpha and Fleiss’ kappa >0.86. A total of 43.92 h of activities were recorded, including 9.52 h of in-lab and 34.41 h of out-of-lab activities. A total of 88.37% and 152.01% of planned transitions were recorded during the in-lab and out-of-lab scenarios, respectively. This study has produced the most detailed dataset to date of inertial sensor data, synchronised with high frame-rate (≥25 fps video labelled data recorded in a free-living environment from older adults living independently. This dataset is suitable for validation of existing activity classification systems and development of new activity classification algorithms.

  10. A finger-shaped tactile sensor for fabric surfaces evaluation by 2-dimensional active sliding touch.

    Science.gov (United States)

    Hu, Haihua; Han, Yezhen; Song, Aiguo; Chen, Shanguang; Wang, Chunhui; Wang, Zheng

    2014-03-11

    Sliding tactile perception is a basic function for human beings to determine the mechanical properties of object surfaces and recognize materials. Imitating this process, this paper proposes a novel finger-shaped tactile sensor based on a thin piezoelectric polyvinylidene fluoride (PVDF) film for surface texture measurement. A parallelogram mechanism is designed to ensure that the sensor applies a constant contact force perpendicular to the object surface, and a 2-dimensional movable mechanical structure is utilized to generate the relative motion at a certain speed between the sensor and the object surface. By controlling the 2-dimensional motion of the finger-shaped sensor along the object surface, small height/depth variation of surface texture changes the output charge of PVDF film then surface texture can be measured. In this paper, the finger-shaped tactile sensor is used to evaluate and classify five different kinds of linen. Fast Fourier Transformation (FFT) is utilized to get original attribute data of surface in the frequency domain, and principal component analysis (PCA) is used to compress the attribute data and extract feature information. Finally, low dimensional features are classified by Support Vector Machine (SVM). The experimental results show that this finger-shaped tactile sensor is effective and high accurate for discriminating the five textures.

  11. 25 CFR 170.137 - What types of activities can a recreation, tourism, and trails program include?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false What types of activities can a recreation, tourism, and... Eligibility Recreation, Tourism and Trails § 170.137 What types of activities can a recreation, tourism, and... may perform under a recreation, tourism, and trails program: (1) Transportation planning for tourism...

  12. Synthesis of CdS nanorod arrays and their applications in flexible piezo-driven active H2S sensors

    International Nuclear Information System (INIS)

    Wang, Penglei; Deng, Ping; Nie, Yuxin; Zhao, Yayu; Xing, Lili; Xue, Xinyu; Zhang, Yan

    2014-01-01

    A flexible piezo-driven active H 2 S sensor has been fabricated from CdS nanorod arrays. By coupling the piezoelectric and gas sensing properties of CdS nanorods, the piezoelectric output generated by CdS nanorod arrays acts not only as a power source, but also as a response signal to H 2 S. Under externally applied compressive force, the piezoelectric output of CdS nanorod arrays is very sensitive to H 2 S. Upon exposure to 600 ppm H 2 S, the piezoelectric output of the device decreased from 0.32 V (in air) to 0.12 V. Such a flexible device can be driven by the tiny mechanical energy in our living environment, such as human finger pinching. Our research can stimulate a research trend on designing new material systems and device structures for high-performance piezo-driven active gas sensors. (paper)

  13. Efficiency calibration and minimum detectable activity concentration of a real-time UAV airborne sensor system with two gamma spectrometers

    International Nuclear Information System (INIS)

    Tang, Xiao-Bin; Meng, Jia; Wang, Peng; Cao, Ye; Huang, Xi; Wen, Liang-Sheng; Chen, Da

    2016-01-01

    A small-sized UAV (NH-UAV) airborne system with two gamma spectrometers (LaBr_3 detector and HPGe detector) was developed to monitor activity concentration in serious nuclear accidents, such as the Fukushima nuclear accident. The efficiency calibration and determination of minimum detectable activity concentration (MDAC) of the specific system were studied by MC simulations at different flight altitudes, different horizontal distances from the detection position to the source term center and different source term sizes. Both air and ground radiation were considered in the models. The results obtained may provide instructive suggestions for in-situ radioactivity measurements of NH-UAV. - Highlights: • A small-sized UAV airborne sensor system was developed. • Three radioactive models were chosen to simulate the Fukushima accident. • Both the air and ground radiation were considered in the models. • The efficiency calculations and MDAC values were given. • The sensor system is able to monitor in serious nuclear accidents.

  14. Voltage dependence of a stochastic model of activation of an alpha helical S4 sensor in a K channel membrane

    Science.gov (United States)

    Vaccaro, S. R.

    2011-09-01

    The voltage dependence of the ionic and gating currents of a K channel is dependent on the activation barriers of a voltage sensor with a potential function which may be derived from the principal electrostatic forces on an S4 segment in an inhomogeneous dielectric medium. By variation of the parameters of a voltage-sensing domain model, consistent with x-ray structures and biophysical data, the lowest frequency of the survival probability of each stationary state derived from a solution of the Smoluchowski equation provides a good fit to the voltage dependence of the slowest time constant of the ionic current in a depolarized membrane, and the gating current exhibits a rising phase that precedes an exponential relaxation. For each depolarizing potential, the calculated time dependence of the survival probabilities of the closed states of an alpha helical S4 sensor are in accord with an empirical model of the ionic and gating currents recorded during the activation process.

  15. Technical note: Evaluation of an ear-attached movement sensor to record cow feeding behavior and activity.

    Science.gov (United States)

    Bikker, J P; van Laar, H; Rump, P; Doorenbos, J; van Meurs, K; Griffioen, G M; Dijkstra, J

    2014-05-01

    The ability to monitor dairy cow feeding behavior and activity could improve dairy herd management. A 3-dimensional accelerometer (SensOor; Agis Automatisering BV, Harmelen, the Netherlands) has been developed that can be attached to ear identification tags. Based on the principle that behavior can be identified by ear movements, a proprietary model classifies sensor data as "ruminating," "eating," "resting," or "active." The objective of the study was to evaluate this sensor on accuracy and precision. First, a pilot evaluation of agreement between 2 independent observers, recording behavior from 3 cows for a period of approximately 9h each, was performed. Second, to evaluate the sensor, the behavior of 15 cows was monitored both visually (VIS) and with the sensor (SENS), with approximately 20 h of registration per cow, evenly distributed over a 24-h period, excluding milking. Cows were chosen from groups of animals in different lactation stages and parities. Each minute of SENS and VIS data was classified into 1 of 9 categories (8 behaviors and 1 transition behavior) and summarized into 4 behavioral groups, namely ruminating, eating, resting, or active, which were analyzed by calculating kappa (κ) values. For the pilot evaluation, a high level of agreement between observers was obtained, with κ values of ≥ 0.96 for all behavioral categories, indicating that visual observation provides a good standard. For the second trial, relationships between SENS and VIS were studied by κ values on a minute basis and Pearson correlation and concordance correlation coefficient analysis on behavior expressed as percentage of total registration time. Times spent ruminating, eating, resting, and active were 42.6, 15.9, 31.6, and 9.9% (SENS) respectively, and 42.1, 13.0, 30.0, and 14.9% (VIS), respectively. Overall κ for the comparison of SENS and VIS was substantial (0.78), with κ values of 0.85, 0.77, 0.86, and 0.47 for "ruminating," "eating," "resting," and "active

  16. Radiation-hard Active Pixel Sensors for HL-LHC Detector Upgrades based on HV-CMOS Technology

    International Nuclear Information System (INIS)

    Miucci, A; Gonzalez-Sevilla, S; Ferrere, D; Iacobucci, G; Rosa, A La; Muenstermann, D; Gonella, L; Hemperek, T; Hügging, F; Krüger, H; Obermann, T; Wermes, N; Garcia-Sciveres, M; Backhaus, M; Capeans, M; Feigl, S; Nessi, M; Pernegger, H; Ristic, B; George, M

    2014-01-01

    Luminosity upgrades are discussed for the LHC (HL-LHC) which would make updates to the detectors necessary, requiring in particular new, even more radiation-hard and granular, sensors for the inner detector region. A proposal for the next generation of inner detectors is based on HV-CMOS: a new family of silicon sensors based on commercial high-voltage CMOS technology, which enables the fabrication of part of the pixel electronics inside the silicon substrate itself. The main advantages of this technology with respect to the standard silicon sensor technology are: low material budget, fast charge collection time, high radiation tolerance, low cost and operation at room temperature. A traditional readout chip is still needed to receive and organize the data from the active sensor and to handle high-level functionality such as trigger management. HV-CMOS has been designed to be compatible with both pixel and strip readout. In this paper an overview of HV2FEI4, a HV-CMOS prototype in 180 nm AMS technology, will be given. Preliminary results after neutron and X-ray irradiation are shown

  17. Harmonic-resonator-based triboelectric nanogenerator as a sustainable power source and a self-powered active vibration sensor.

    Science.gov (United States)

    Chen, Jun; Zhu, Guang; Yang, Weiqing; Jing, Qingshen; Bai, Peng; Yang, Ya; Hou, Te-Chien; Wang, Zhong Lin

    2013-11-13

    A harmonic-resonator-based triboelectric nanogenerator (TENG) is presented as a sustainable power source and an active vibration sensor. It can effectively respond to vibration frequencies ranging from 2 to 200 Hz with a considerably wide working bandwidth of 13.4 Hz. This work not only presents a new principle in the field of vibration energy harvesting but also greatly expands the applicability of TENGs. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. X-RAY ACTIVE MATRIX PIXEL SENSORS BASEDON J-FET TECHNOLOGY DEVELOPED FOR THE LINAC COHERENT LIGHT SOURCE.

    Energy Technology Data Exchange (ETDEWEB)

    CARINI,G.A.; CHEN, W.; LI, Z.; REHAK, P.; SIDDONS, D.P.

    2007-10-29

    An X-ray Active Matrix Pixel Sensor (XAMPS) is being developed for recording data for the X-ray Pump Probe experiment at the Linac Coherent Light Source (LCLS). Special attention has to be paid to some technological challenges that this design presents. New processes were developed and refined to address problems encountered during previous productions of XAMPS. The development of these critical steps and corresponding tests results are reported here.

  19. HDOMO: Smart Sensor Integration for an Active and Independent Longevity of the Elderly.

    Science.gov (United States)

    Frontoni, Emanuele; Pollini, Rama; Russo, Paola; Zingaretti, Primo; Cerri, Graziano

    2017-11-13

    The aim of this paper is to present the main results of HDOMO, an Ambient Assisted Living (AAL) project that involved 16 Small and Medium Enterprises (SMEs) and 2 research institutes. The objective of the project was to create an autonomous and automated domestic environment, primarily for elderly people and people with physical and motor disabilities. A known and familiar environment should help users in their daily activities and it should act as a virtual caregiver by calling, if necessary, relief efforts. Substantially, the aim of the project is to simplify the life of people in need of support, while keeping them autonomous in their private environment. From a technical point of view, the project provides the use of different Smart Objects (SOs), able to communicate among each other, in a cloud base infrastructure, and with the assisted users and their caregivers, in a perspective of interoperability and standardization of devices, usability and effectiveness of alarm systems. In the state of the art there are projects that achieve only a few of the elements listed. The HDOMO project aims to achieve all of them in one single project effectively. The experimental trials performed in a real scenario demonstrated the accuracy and efficiency of the system in extracting and processing data in real time to promptly acting, and in providing timely response to the needs of the user by integrating and confirming main alarms with different interoperable smart sensors. The article proposes a new technique to improve the accuracy of the system in detecting alarms using a multi-SO approach with information fusion between different devices, proving that this architecture can provide robust and reliable results on real environments.

  20. HDOMO: Smart Sensor Integration for an Active and Independent Longevity of the Elderly

    Science.gov (United States)

    2017-01-01

    The aim of this paper is to present the main results of HDOMO, an Ambient Assisted Living (AAL) project that involved 16 Small and Medium Enterprises (SMEs) and 2 research institutes. The objective of the project was to create an autonomous and automated domestic environment, primarily for elderly people and people with physical and motor disabilities. A known and familiar environment should help users in their daily activities and it should act as a virtual caregiver by calling, if necessary, relief efforts. Substantially, the aim of the project is to simplify the life of people in need of support, while keeping them autonomous in their private environment. From a technical point of view, the project provides the use of different Smart Objects (SOs), able to communicate among each other, in a cloud base infrastructure, and with the assisted users and their caregivers, in a perspective of interoperability and standardization of devices, usability and effectiveness of alarm systems. In the state of the art there are projects that achieve only a few of the elements listed. The HDOMO project aims to achieve all of them in one single project effectively. The experimental trials performed in a real scenario demonstrated the accuracy and efficiency of the system in extracting and processing data in real time to promptly acting, and in providing timely response to the needs of the user by integrating and confirming main alarms with different interoperable smart sensors. The article proposes a new technique to improve the accuracy of the system in detecting alarms using a multi-SO approach with information fusion between different devices, proving that this architecture can provide robust and reliable results on real environments. PMID:29137174

  1. Research and Development of Monolithic Active Pixel Sensors for the Detection of the Elementary Particles

    International Nuclear Information System (INIS)

    Li, Y.

    2007-09-01

    In order to develop high spatial resolution and readout speed vertex detectors for the future International Linear Collider (ILC), fast CMOS Monolithic Active Pixel Sensors (MAPS) are studied on this work. Two prototypes of MAPS, MIMOSA 8 and MIMOSA 16, based on the same micro-electronic architecture were developed in CMOS processes with different thickness of epitaxial layer. The size of pixel matrix is 32 x 128: 8 columns of the pixel array are readout directly with analog outputs and the other 24 columns are connected to the column level auto-zero discriminators. The Correlated Double Sampling (CDS) structures are successfully implemented inside pixel and discriminator. The photo diode type pixels with different diode sizes are used in these prototypes. With a 55 Fe X-ray radioactive source, the important parameters, such as Temporal Noise, Fixed Pattern Noise (FPN), Signal-to-Noise Ratio (SNR), Charge-to-Voltage conversion Factor (CVF) and Charge Collection Efficiency (CCE), are studied as function of readout speed and diode size. For MIMOSA 8, the effect of fast neutrons irradiation is also. Two beam tests campaigns were made: at DESY with a 5 GeV electrons beam and at CERN with a 180 GeV pions beam. Detection Efficiency and Spatial Resolution are studied in function of the discriminator threshold. For these two parameters, the influences of diode size and SNR of the central pixel of a cluster are also discussed. In order to improve the spatial resolution of the digital outputs, a very compact (25 μm x 1 mm) and low consumption (300 μW) column level ADC is designed in AMS 0.35 μm OPTO process. Based on successive approximation architecture, the auto-offset cancellation structure is integrated. A new column level auto-zero discriminator using static latch is also designed. (author)

  2. Long-term fluorescence lifetime imaging of a genetically encoded sensor for caspase-3 activity in mouse tumor xenografts

    Science.gov (United States)

    Zherdeva, Victoria; Kazachkina, Natalia I.; Shcheslavskiy, Vladislav; Savitsky, Alexander P.

    2018-03-01

    Caspase-3 is known for its role in apoptosis and programmed cell death regulation. We detected caspase-3 activation in vivo in tumor xenografts via shift of mean fluorescence lifetimes of a caspase-3 sensor. We used the genetically encoded sensor TR23K based on the red fluorescent protein TagRFP and chromoprotein KFP linked by 23 amino acid residues (TagRFP-23-KFP) containing a specific caspase cleavage DEVD motif to monitor the activity of caspase-3 in tumor xenografts by means of fluorescence lifetime imaging-Forster resonance energy transfer. Apoptosis was induced by injection of paclitaxel for A549 lung adenocarcinoma and etoposide and cisplatin for HEp-2 pharynx adenocarcinoma. We observed a shift in lifetime distribution from 1.6 to 1.9 ns to 2.1 to 2.4 ns, which indicated the activation of caspase-3. Even within the same tumor, the lifetime varied presumably due to the tumor heterogeneity and the different depth of tumor invasion. Thus, processing time-resolved fluorescence images allows detection of both the cleaved and noncleaved states of the TR23K sensor in real-time mode during the course of several weeks noninvasively. This approach can be used in drug screening, facilitating the development of new anticancer agents as well as improvement of chemotherapy efficiency and its adaptation for personal treatment.

  3. The mechanism by which a propeptide-encoded pH sensor regulates spatiotemporal activation of furin.

    Science.gov (United States)

    Williamson, Danielle M; Elferich, Johannes; Ramakrishnan, Parvathy; Thomas, Gary; Shinde, Ujwal

    2013-06-28

    The proprotein convertase furin requires the pH gradient of the secretory pathway to regulate its multistep, compartment-specific autocatalytic activation. Although His-69 within the furin prodomain serves as the pH sensor that detects transport of the propeptide-enzyme complex to the trans-Golgi network, where it promotes cleavage and release of the inhibitory propeptide, a mechanistic understanding of how His-69 protonation mediates furin activation remains unclear. Here we employ biophysical, biochemical, and computational approaches to elucidate the mechanism underlying the pH-dependent activation of furin. Structural analyses and binding experiments comparing the wild-type furin propeptide with a nonprotonatable His-69 → Leu mutant that blocks furin activation in vivo revealed protonation of His-69 reduces both the thermodynamic stability of the propeptide as well as its affinity for furin at pH 6.0. Structural modeling combined with mathematical modeling and molecular dynamic simulations suggested that His-69 does not directly contribute to the propeptide-enzyme interface but, rather, triggers movement of a loop region in the propeptide that modulates access to the cleavage site and, thus, allows for the tight pH regulation of furin activation. Our work establishes a mechanism by which His-69 functions as a pH sensor that regulates compartment-specific furin activation and provides insights into how other convertases and proteases may regulate their precise spatiotemporal activation.

  4. The Mechanism by Which a Propeptide-encoded pH Sensor Regulates Spatiotemporal Activation of Furin*

    Science.gov (United States)

    Williamson, Danielle M.; Elferich, Johannes; Ramakrishnan, Parvathy; Thomas, Gary; Shinde, Ujwal

    2013-01-01

    The proprotein convertase furin requires the pH gradient of the secretory pathway to regulate its multistep, compartment-specific autocatalytic activation. Although His-69 within the furin prodomain serves as the pH sensor that detects transport of the propeptide-enzyme complex to the trans-Golgi network, where it promotes cleavage and release of the inhibitory propeptide, a mechanistic understanding of how His-69 protonation mediates furin activation remains unclear. Here we employ biophysical, biochemical, and computational approaches to elucidate the mechanism underlying the pH-dependent activation of furin. Structural analyses and binding experiments comparing the wild-type furin propeptide with a nonprotonatable His-69 → Leu mutant that blocks furin activation in vivo revealed protonation of His-69 reduces both the thermodynamic stability of the propeptide as well as its affinity for furin at pH 6.0. Structural modeling combined with mathematical modeling and molecular dynamic simulations suggested that His-69 does not directly contribute to the propeptide-enzyme interface but, rather, triggers movement of a loop region in the propeptide that modulates access to the cleavage site and, thus, allows for the tight pH regulation of furin activation. Our work establishes a mechanism by which His-69 functions as a pH sensor that regulates compartment-specific furin activation and provides insights into how other convertases and proteases may regulate their precise spatiotemporal activation. PMID:23653353

  5. Efficient room temperature hydrogen sensor based on UV-activated ZnO nano-network

    Science.gov (United States)

    Kumar, Mohit; Kumar, Rahul; Rajamani, Saravanan; Ranwa, Sapana; Fanetti, Mattia; Valant, Matjaz; Kumar, Mahesh

    2017-09-01

    Room temperature hydrogen sensors were fabricated from Au embedded ZnO nano-networks using a 30 mW GaN ultraviolet LED. The Au-decorated ZnO nano-networks were deposited on a SiO2/Si substrate by a chemical vapour deposition process. X-ray diffraction (XRD) spectrum analysis revealed a hexagonal wurtzite structure of ZnO and presence of Au. The ZnO nanoparticles were interconnected, forming nano-network structures. Au nanoparticles were uniformly distributed on ZnO surfaces, as confirmed by FESEM imaging. Interdigitated electrodes (IDEs) were fabricated on the ZnO nano-networks using optical lithography. Sensor performances were measured with and without UV illumination, at room temperate, with concentrations of hydrogen varying from 5 ppm to 1%. The sensor response was found to be ˜21.5% under UV illumination and 0% without UV at room temperature for low hydrogen concentration of 5 ppm. The UV-photoactivated mode enhanced the adsorption of photo-induced O- and O2- ions, and the d-band electron transition from the Au nanoparticles to ZnO—which increased the chemisorbed reaction between hydrogen and oxygen. The sensor response was also measured at 150 °C (without UV illumination) and found to be ˜18% at 5 ppm. Energy efficient low cost hydrogen sensors can be designed and fabricated with the combination of GaN UV LEDs and ZnO nanostructures.

  6. Multi trace element analysis of dry biological materials by neutron activation analysis including a chemical group separation

    International Nuclear Information System (INIS)

    Weers, C.A.

    1980-01-01

    The principles of activation analysis and the practical aspects of neutron activation analysis are outlined. The limits which are set to accuracy and precision are defined. The description of the evaporation process is summarised in terms of the half-volume. This quantity is then used to define the resolving power. The formulation is checked by radiotracer experiments. Dried animal blood is used as the testing material. The pretreatment of the samples and (the development of) the destruction-evaporation apparatus is described. Four successive devices were built and tested. The development of the successive adsorption steps with active charcoal, Al 2 O 3 and coprecipitation with Fe(OH) 3 is presented. Seven groups of about 25 elements in total can be determined this way. The results obtained for standard reference materials are summarized and compared with literature data. (Auth.)

  7. A CMOS active pixel sensor system for laboratory- based x-ray diffraction studies of biological tissue

    International Nuclear Information System (INIS)

    Bohndiek, Sarah E; Cook, Emily J; Arvanitis, Costas D; Olivo, Alessandro; Royle, Gary J; Clark, Andy T; Prydderch, Mark L; Turchetta, Renato; Speller, Robert D

    2008-01-01

    X-ray diffraction studies give material-specific information about biological tissue. Ideally, a large area, low noise, wide dynamic range digital x-ray detector is required for laboratory-based x-ray diffraction studies. The goal of this work is to introduce a novel imaging technology, the CMOS active pixel sensor (APS) that has the potential to fulfil all these requirements, and demonstrate its feasibility for coherent scatter imaging. A prototype CMOS APS has been included in an x-ray diffraction demonstration system. An industrial x-ray source with appropriate beam filtration is used to perform angle dispersive x-ray diffraction (ADXRD). Optimization of the experimental set-up is detailed including collimator options and detector operating parameters. Scatter signatures are measured for 11 different materials, covering three medical applications: breast cancer diagnosis, kidney stone identification and bone mineral density calculations. Scatter signatures are also recorded for three mixed samples of known composition. Results are verified using two independent models for predicting the APS scatter signature: (1) a linear systems model of the APS and (2) a linear superposition integral combining known monochromatic scatter signatures with the input polychromatic spectrum used in this case. Cross validation of experimental, modelled and literature results proves that APS are able to record biologically relevant scatter signatures. Coherent scatter signatures are sensitive to multiple materials present in a sample and provide a means to quantify composition. In the future, production of a bespoke APS imager for x-ray diffraction studies could enable simultaneous collection of the transmitted beam and scattered radiation in a laboratory-based coherent scatter system, making clinical transfer of the technique attainable

  8. MEMS sensor technologies for human centred applications in healthcare, physical activities, safety and environmental sensing: a review on research activities in Italy.

    Science.gov (United States)

    Ciuti, Gastone; Ricotti, Leonardo; Menciassi, Arianna; Dario, Paolo

    2015-03-17

    Over the past few decades the increased level of public awareness concerning healthcare, physical activities, safety and environmental sensing has created an emerging need for smart sensor technologies and monitoring devices able to sense, classify, and provide feedbacks to users' health status and physical activities, as well as to evaluate environmental and safety conditions in a pervasive, accurate and reliable fashion. Monitoring and precisely quantifying users' physical activity with inertial measurement unit-based devices, for instance, has also proven to be important in health management of patients affected by chronic diseases, e.g., Parkinson's disease, many of which are becoming highly prevalent in Italy and in the Western world. This review paper will focus on MEMS sensor technologies developed in Italy in the last three years describing research achievements for healthcare and physical activity, safety and environmental sensing, in addition to smart systems integration. Innovative and smart integrated solutions for sensing devices, pursued and implemented in Italian research centres, will be highlighted, together with specific applications of such technologies. Finally, the paper will depict the future perspective of sensor technologies and corresponding exploitation opportunities, again with a specific focus on Italy.

  9. MEMS Sensor Technologies for Human Centred Applications in Healthcare, Physical Activities, Safety and Environmental Sensing: A Review on Research Activities in Italy

    Directory of Open Access Journals (Sweden)

    Gastone Ciuti

    2015-03-01

    Full Text Available Over the past few decades the increased level of public awareness concerning healthcare, physical activities, safety and environmental sensing has created an emerging need for smart sensor technologies and monitoring devices able to sense, classify, and provide feedbacks to users’ health status and physical activities, as well as to evaluate environmental and safety conditions in a pervasive, accurate and reliable fashion. Monitoring and precisely quantifying users’ physical activity with inertial measurement unit-based devices, for instance, has also proven to be important in health management of patients affected by chronic diseases, e.g., Parkinson’s disease, many of which are becoming highly prevalent in Italy and in the Western world. This review paper will focus on MEMS sensor technologies developed in Italy in the last three years describing research achievements for healthcare and physical activity, safety and environmental sensing, in addition to smart systems integration. Innovative and smart integrated solutions for sensing devices, pursued and implemented in Italian research centres, will be highlighted, together with specific applications of such technologies. Finally, the paper will depict the future perspective of sensor technologies and corresponding exploitation opportunities, again with a specific focus on Italy.

  10. Physical activity and performance at school A systematic review of the literature including a methodological quality assessment

    NARCIS (Netherlands)

    Singh, A.S.; Uijtdewilligen, L.; Twisk, J.W.; van Mechelen, W.; Chin A Paw, M.J.M.

    2012-01-01

    Objective: To describe the prospective relationship between physical activity and academic performance. Data Sources: Prospective studies were identified from searches in PubMed, PsycINFO, Cochrane Central, and Sportdiscus from 1990 through 2010. Study Selection: We screened the titles and abstracts

  11. Research on Chemical Composition and Biological Properties Including Antiquorum Sensing Activity of Angelica pancicii Vandas Aerial Parts and Roots.

    Science.gov (United States)

    Mileski, Ksenija S; Trifunović, Snežana S; Ćirić, Ana D; Šakić, Željana M; Ristić, Mihailo S; Todorović, Nina M; Matevski, Vlado S; Marin, Petar D; Tešević, Vele V; Džamić, Ana M

    2017-12-20

    The essential oil, different extracts, and isolated compounds of Angelica pancicii Vandas (Apiaceae) were investigated for the first time. The GC-FID and GC-MS analyses revealed sesquiterpenoids as the main constituents of A. pancicii essential oil of aerial parts with bornyl acetate (8.08%), n-octanol (5.82%), kessane (4.26%), and β-selinene (4.26%) as the main constituents. Analysis of methanol extracts, using an HPLC-DAD/ESI-ToF-MS system, showed a total of 52 compounds in the aerial parts and 53 in the roots, indicating coumarins as the main constituents. In addition, new chromone (1) and six known furanocoumarins (2-7) were isolated from the roots and structurally elucidated by combined spectroscopic methods. The aerial part extracts exhibited higher polyphenolic contents and antioxidant activity evaluated by three radical scavenging assays. Using a microwell dilution method, the strongest antibacterial activity profiles were determined for ethanol and methanol root extracts (minimum bactericidal concentrations (MBCs) = 0.25-3.00 mg/mL), which were comparable to the activity of streptomycin (MBCs = 0.34-1.24 mg/mL), while the strongest antibacterial compound of A. pancicii was oxypeucedanin hydrate (MBCs = 0.50-8.00 mg/mL). Antifungal potential was in moderate extent, and the highest activity was obtained for root methanol extract (minimum fungicidal concentrations (MFCs) = 4.00-14.00 mg/mL). Tested sub-minimum inhibitory concentrations (subMICs) of the extracts and isolated compounds inhibited selected Pseudomonas aeruginosa PAO1 virulence determinants. The most reduced growth of P. aeruginosa colony was in the presence of isolated oxypeucedanin. Ethanol (17.36-46.98%) and methanol (34.54-52.43%) root extracts showed higher anti-biofilm activity compared to streptomycin (49.40-88.36%) and ampicillin (56.46-92.16%).

  12. Noise analysis of a novel hybrid active-passive pixel sensor for medical X-ray imaging

    International Nuclear Information System (INIS)

    Safavian, N.; Izadi, M.H.; Sultana, A.; Wu, D.; Karim, K.S.; Nathan, A.; Rowlands, J.A.

    2009-01-01

    Passive pixel sensor (PPS) is one of the most widely used architectures in large area amorphous silicon (a-Si) flat panel imagers. It consists of a detector and a thin film transistor (TFT) acting as a readout switch. While the PPS is advantageous in terms of providing a simple and small architecture suitable for high-resolution imaging, it directly exposes the signal to the noise of data line and external readout electronics, causing significant increase in the minimum readable sensor input signal. In this work we present the operation and noise performance of a hybrid 3-TFT current programmed, current output active pixel sensor (APS) suitable for real-time X-ray imaging. The pixel circuit extends the application of a-Si TFT from conventional switching element to on-pixel amplifier for enhanced signal-to-noise ratio and higher imager dynamic range. The capability of operation in both passive and active modes as well as being able to compensate for inherent instabilities of the TFTs makes the architecture a good candidate for X-ray imaging modalities with a wide range of incoming X-ray intensities. Measurement and theoretical calculations reveal a value for input refferd noise below the 1000 electron noise limit for real-time fluoroscopy. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. ARC (NSC 188491 has identical activity to Sangivamycin (NSC 65346 including inhibition of both P-TEFb and PKC

    Directory of Open Access Journals (Sweden)

    Hollingshead Melinda G

    2009-02-01

    Full Text Available Abstract Background The nucleoside analog, ARC (NSC 188491 is a recently characterized transcriptional inhibitor that selectively kills cancer cells and has the ability to perturb angiogenesis in vitro. In this study, the mechanism of action of ARC was further investigated by comparing in vitro and in vivo activity with other anti-neoplastic purines. Methods Structure-based homology searches were used to identify those compounds with similarity to ARC. Comparator compounds were then evaluated alongside ARC in the context of viability, cell cycle and apoptosis assays to establish any similarities. Following this, biological overlap was explored in detail using gene-expression analysis and kinase inhibition assays. Results Results demonstrated that sangivamycin, an extensively characterized pro-apoptotic nucleoside isolated from Streptomyces, had identical activity to ARC in terms of 1 cytotoxicity assays, 2 ability to induce a G2/M block, 3 inhibitory effects on RNA/DNA/protein synthesis, 4 transcriptomic response to treatment, 5 inhibition of protein kinase C, 6 inhibition of positive transcription elongation factor b (P-TEFb, 7 inhibition of VEGF secretion, and 8 activity within hollow fiber assays. Extending ARC activity to PKC inhibition provides a molecular basis for ARC cancer selectivity and anti-angiogenic effects. Furthermore, functional overlap between ARC and sangivamycin suggests that development of ARC may benefit from a retrospective of previous sangivamycin clinical trials. However, ARC was found to be inactive in several xenograft models, likely a consequence of rapid serum clearance. Conclusion Overall, these data expand on the biological properties of ARC but suggest additional studies are required before it can be considered a clinical trials candidate.

  14. Consistent sensor, relay, and link selection in wireless sensor networks

    NARCIS (Netherlands)

    Arroyo Valles, M.D.R.; Simonetto, A.; Leus, G.J.T.

    2017-01-01

    In wireless sensor networks, where energy is scarce, it is inefficient to have all nodes active because they consume a non-negligible amount of battery. In this paper we consider the problem of jointly selecting sensors, relays and links in a wireless sensor network where the active sensors need

  15. Sensors an introductory course

    CERN Document Server

    Kalantar-zadeh, Kourosh

    2013-01-01

    Sensors: An Introductory Course provides an essential reference on the fundamentals of sensors. The book is designed to help readers in developing skills and the understanding required in order to implement a wide range of sensors that are commonly used in our daily lives. This book covers the basic concepts in the sensors field, including definitions and terminologies. The physical sensing effects are described, and devices which utilize these effects are presented. The most frequently used organic and inorganic sensors are introduced and the techniques for implementing them are discussed. This book: Provides a comprehensive representation of the most common sensors and can be used as a reference in relevant fields Presents learning materials in a concise and easy to understand manner Includes examples of how sensors are incorporated in real life measurements Contains detailed figures and schematics to assist in understanding the sensor performance Sensors: An Introductory Course is ideal for university stu...

  16. Comparison of Self-Report Versus Sensor-Based Methods for Measuring the Amount of Upper Limb Activity Outside the Clinic.

    Science.gov (United States)

    Waddell, Kimberly J; Lang, Catherine E

    2018-03-10

    To compare self-reported with sensor-measured upper limb (UL) performance in daily life for individuals with chronic (≥6mo) UL paresis poststroke. Secondary analysis of participants enrolled in a phase II randomized, parallel, dose-response UL movement trial. This analysis compared the accuracy and consistency between self-reported UL performance and sensor-measured UL performance at baseline and immediately post an 8-week intensive UL task-specific intervention. Outpatient rehabilitation. Community-dwelling individuals with chronic (≥6mo) UL paresis poststroke (N=64). Not applicable. Motor Activity Log amount of use scale and the sensor-derived use ratio from wrist-worn accelerometers. There was a high degree of variability between self-reported UL performance and the sensor-derived use ratio. Using sensor-based values as a reference, 3 distinct categories were identified: accurate reporters (reporting difference ±0.1), overreporters (difference >0.1), and underreporters (difference sensor-based assessment. Participants did not consistently or accurately self-report UL performance when compared with the sensor-derived use ratio. Although self-report and sensor-based assessments are moderately associated and appear similar conceptually, these results suggest self-reported UL performance is often not consistent with sensor-measured performance and the measures cannot be used interchangeably. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  17. Development of a Large-Format Science-Grade CMOS Active Pixel Sensor, for Extreme Ultra Violet Spectroscopy and Imaging in Space Science

    National Research Council Canada - National Science Library

    Waltham, N. R; Prydderch, M; Mapson-Menard, H; Morrissey, Q; Turchetta, R; Pool, P; Harris, A

    2005-01-01

    We describe our programme to develop a large-format science-grade CMOS active pixel sensor for future space science missions, and in particular an extreme ultra-violet spectrograph for solar physics...

  18. Evaluation of Cholinesterase Activities During in Vivo Intoxication Using an Electrochemical Sensor Strip – Correlation With Intoxication Symptoms

    Directory of Open Access Journals (Sweden)

    Jana Zdarova-Karasova

    2009-05-01

    Full Text Available Cholinesterase activity in blood of laboratory rats was monitored. Rats were intoxicated with paraoxon at dosis of 0 – 65 – 125 – 170 – 250 – 500 nmol. The 250 nmol dose was found to be the LD50. An electrochemical sensor was found useful to provide information about cholinesterase activity. The decrease of cholinesterase activity was correlated to intoxication symptoms and mortality level. It was found that the symptoms of intoxication are not observed while at least 50% of cholinesterase activity in blood remains. The minimal cholinesterase activity essential to survival is around 10%, when compared with the initial state. No changes in levels of low moleculary weight antioxidants were observed.

  19. Real-time investigation of human topoisomerase I reaction kinetics using an optical sensor: a fast method for drug screening and determination of active enzyme concentrations

    Science.gov (United States)

    Kristoffersen, Emil L.; Jørgensen, Line A.; Franch, Oskar; Etzerodt, Michael; Frøhlich, Rikke; Bjergbæk, Lotte; Stougaard, Magnus; Ho, Yi-Ping; Knudsen, Birgitta R.

    2015-05-01

    Human DNA topoisomerase I (hTopI) is a nuclear enzyme that catalyzes relaxation of super helical tension that arises in the genome during essential DNA metabolic processes. This is accomplished through a common reaction mechanism shared among the type IB topoisomerase enzymes, including eukaryotic and poxvirus topoisomerase I. The mechanism of hTopI is specifically targeted in cancer treatment using camptothecin derivatives. These drugs convert the hTopI activity into a cellular poison, and hence the cytotoxic effects of camptothecin derivatives correlate with the hTopI activity. Therefore, fast and reliable techniques for high throughput measurements of hTopI activity are of high clinical interest. Here we demonstrate potential applications of a fluorophore-quencher based DNA sensor designed for measurement of hTopI cleavage-ligation activities, which are the catalytic steps affected by camptothecin. The kinetic analysis of the hTopI reaction with the DNA sensor exhibits a characteristic burst profile. This is the result of a two-step ping-pong reaction mechanism, where a fast first reaction, the one creating the signal, is followed by a slower second reaction necessary for completion of the catalytic cycle. Hence, the burst profile holds information about two reactions in the enzymatic mechanism. Moreover, it allows the amount of active enzyme in the reaction to be determined. The presented results pave the way for future high throughput drug screening and the potential of measuring active hTopI concentrations in clinical samples for individualized treatment.Human DNA topoisomerase I (hTopI) is a nuclear enzyme that catalyzes relaxation of super helical tension that arises in the genome during essential DNA metabolic processes. This is accomplished through a common reaction mechanism shared among the type IB topoisomerase enzymes, including eukaryotic and poxvirus topoisomerase I. The mechanism of hTopI is specifically targeted in cancer treatment using

  20. Extended automated separation techniques in destructive neutron activation analysis; application to various biological materials, including human tissues and blood

    International Nuclear Information System (INIS)

    Tjioe, P.S.; Goeij, J.J.M. de; Houtman, J.P.W.

    1976-09-01

    Neutron activation analysis may be performed as a multi-element and low-level technique for many important trace elements in biological materials, provided that post-irradiation chemical separations are applied. This paper describes a chemical separation consisting of automated procedures for destruction, distillation, and anion-chromatography. The system developed enables the determination of 14 trace elements in biological materials, viz. antimony, arsenic, bromine, cadmium, chromium, cobalt, copper, gold, iron, mercury, molybdenum, nickel, selenium, and zinc. The aspects of sample preparation, neutron irradiation, gamma-spectrum evaluation, and blank-value contribution are also discussed