WorldWideScience

Sample records for based room correction

  1. Predicting Correct Body Posture based on Theory of Planned Behavior in Iranian Operating Room Nurses

    Directory of Open Access Journals (Sweden)

    BAHAREH ABEDI

    2015-06-01

    Full Text Available Due to the importance of correct posture for preventing musculoskeletal disorders, the purpose of this study was to evaluate Theory of Planned Behavior in Predicting correct Body Posture in operating room nurses.In this cross-sectional study, participants (n=100 were nurses from five hospitals located in northern Iran. Participants completed demographic data and theory of planned behavior construct Questionnaires. In addition, the researcher checked the Body Posture of nurses by Rapid Entire Body Assessment (REBA.The Meanage of nurses was 33.54 yr, (SD=6/51.Multivariate regression showed that attitudes and perceived behavioral control werepredictive of behavioral intention of nurses’readiness to assume correct posture (P<0.001, R2=0.31, nurses who had more positive attitude and more perceived behavioral control were more likely to have intentions towards correct body posture. Furthermore, only behavioral intention is predictive of readiness correct posture among nurses. Nurses who had more behavioral intentionfor correct body posture were more likely to intend to do.The attitudes and perceived behavioral control were predictive of behavioral intentions for correct body posture.Therefore, the design of intervention strategies based on the promotion of attitudes and perceived behavioral control was recommended to nurses.

  2. Applications of a plane wave based room correction system for low frequencies using multiple loudspeakers

    DEFF Research Database (Denmark)

    Celestinos, Adrian; Nielsen, Sofus Birkedal

    2008-01-01

    System (CABS) produces uniform sound field at low frequencies. This is performed by utilizing loudspeakers at the front wall and extra loudspeakers at the opposite wall, processed to remove the rear-wall reflection of a rectangular room. Effectiveness of CABS on different room scenarios has been...

  3. Web based emergency room PACS

    International Nuclear Information System (INIS)

    We wished to develop the web based Picture Archiving and Communication System in the emergency room for early decision making in emergency treatment planning at a full PACS Hospital. The program tools were Microsoft Visual Studio 6.0 - Visual C++ 6.0, and the Microsoft SQL 7.0 under the Microsoft Windows 2000 server operation system. The achievement of images was performed by an auto transport program installed in the ER and the radiology department. The average compression rates were 5:1 for CT and MR, and 20:1 for CR with JPEG 2000 lossy compression. All the images were stored on hard disk for 3 months. The patients' information was displayed for 2 weeks for reducing the security risk. For interdepartmental consultation, patient query by patient hospital number was available. Our Web based ER PACS could be useful system for early decision making for treatment planning in the emergency room because it reduces the risk factors for the security of the Web Paces by using a system independent from PACS in the hospital and minimizing the information patients

  4. 75 FR 5536 - Pipeline Safety: Control Room Management/Human Factors, Correction

    Science.gov (United States)

    2010-02-03

    ... Safety: Control Room Management/Human Factors, Correction AGENCY: Pipeline and Hazardous Materials Safety... Regulations to address human factors and other aspects of control room management for pipelines where... 63310) entitled ``Pipeline Safety: Control Room Management/Human Factors.'' This final rule...

  5. Dispersion based beam tilt correction

    CERN Document Server

    Guetg, Marc W; Prat, Eduard; Reiche, Sven

    2013-01-01

    In Free Electron Lasers (FEL), a transverse centroid misalignment of longitudinal slices in an electron bunch reduces the effective overlap between radiation field and electron bunch and therefore the FEL performance. The dominant sources of slice misalignments for FELs are the incoherent and coherent synchrotron radiation within bunch compressors as well as transverse wake fields in the accelerating cavities. This is of particular importance for over-compression which is required for one of the key operation modes for the SwissFEL planned at the Paul Scherrer Institute. The centroid shift is corrected using corrector magnets in dispersive sections, e.g. the bunch compressors. First and second order corrections are achieved by pairs of sextupole and quadrupole magnets in the horizontal plane while skew quadrupoles correct to first order in the vertical plane. Simulations and measurements at the SwissFEL Injector Test Facility are done to investigate the proposed correction scheme for SwissFEL. This paper pres...

  6. A Pen-Based System for the Psychiatric Emergency Room

    OpenAIRE

    Kennedy, Robert S.

    1995-01-01

    Translating paper based clinical assessment forms to computer based forms for a Psychiatric Emergency Room was facilitated by the use of a computer using Windows for Pen® system and a familiar database. Offering a smooth transition from paper to electronic forms was the primary goal for this busy metropolitan Psychiatric Emergency Room.

  7. LoRA: A Loudspeaker-Based Room Auralization System

    DEFF Research Database (Denmark)

    Favrot, Sylvain Emmanuel; Buchholz, Jörg

    2010-01-01

    In order to study basic human perception in reverberant environments, a novel loudspeaker-based room auralization (LoRA) system is proposed in this paper. The LoRA system efficiently combines modern room acoustic models with high-order Ambisonic auralization. An objective evaluation has been...... carried out demonstrating the applicability of the LoRA system. Room acoustic parameters (reverberation time, clarity, speech transmission index and inter-aural cross correlation coefficients) of room impulse responses were compared at the input and the simulated output of the LoRA system. Results show...

  8. A refined tip correction based on decambering

    DEFF Research Database (Denmark)

    Sørensen, Jens Nørkær; Dag, Kaya Onur; Ramos García, Néstor

    2016-01-01

    A new tip correction for use in performance codes based on the blade element momentum (BEM) or the lifting-line techniqueis presented. The correction modifies the circulation by taking into account the additional influence of the inductionof the vortices in the wake, using the so-called decamberi...

  9. Requirements for Control Room Computer-Based Procedures for use in Hybrid Control Rooms

    Energy Technology Data Exchange (ETDEWEB)

    Le Blanc, Katya Lee [Idaho National Lab. (INL), Idaho Falls, ID (United States); Oxstrand, Johanna Helene [Idaho National Lab. (INL), Idaho Falls, ID (United States); Joe, Jeffrey Clark [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-05-01

    Many plants in the U.S. are currently undergoing control room modernization. The main drivers for modernization are the aging and obsolescence of existing equipment, which typically results in a like-for-like replacement of analogue equipment with digital systems. However, the modernization efforts present an opportunity to employ advanced technology that would not only extend the life, but enhance the efficiency and cost competitiveness of nuclear power. Computer-based procedures (CBPs) are one example of near-term advanced technology that may provide enhanced efficiencies above and beyond like for like replacements of analog systems. Researchers in the LWRS program are investigating the benefits of advanced technologies such as CBPs, with the goal of assisting utilities in decision making during modernization projects. This report will describe the existing research on CBPs, discuss the unique issues related to using CBPs in hybrid control rooms (i.e., partially modernized analog control rooms), and define the requirements of CBPs for hybrid control rooms.

  10. Screen-based control rooms: a vision of the future

    International Nuclear Information System (INIS)

    So much progress has been made in developing digital operational and safety instrumentation and control systems, and screen-based visualization systems are now so advanced, that the screen-based control room will soon be a viable option for nuclear power plants. The possibilities are examined here. (author)

  11. [Design and Implementation of a Mobile Operating Room Information Management System Based on Electronic Medical Record].

    Science.gov (United States)

    Liu, Baozhen; Liu, Zhiguo; Wang, Xianwen

    2015-06-01

    A mobile operating room information management system with electronic medical record (EMR) is designed to improve work efficiency and to enhance the patient information sharing. In the operating room, this system acquires the information from various medical devices through the Client/Server (C/S) pattern, and automatically generates XML-based EMR. Outside the operating room, this system provides information access service by using the Browser/Server (B/S) pattern. Software test shows that this system can correctly collect medical information from equipment and clearly display the real-time waveform. By achieving surgery records with higher quality and sharing the information among mobile medical units, this system can effectively reduce doctors' workload and promote the information construction of the field hospital. PMID:26485982

  12. [Design and Implementation of a Mobile Operating Room Information Management System Based on Electronic Medical Record].

    Science.gov (United States)

    Liu, Baozhen; Liu, Zhiguo; Wang, Xianwen

    2015-06-01

    A mobile operating room information management system with electronic medical record (EMR) is designed to improve work efficiency and to enhance the patient information sharing. In the operating room, this system acquires the information from various medical devices through the Client/Server (C/S) pattern, and automatically generates XML-based EMR. Outside the operating room, this system provides information access service by using the Browser/Server (B/S) pattern. Software test shows that this system can correctly collect medical information from equipment and clearly display the real-time waveform. By achieving surgery records with higher quality and sharing the information among mobile medical units, this system can effectively reduce doctors' workload and promote the information construction of the field hospital.

  13. Exemplar-based human action pose correction.

    Science.gov (United States)

    Shen, Wei; Deng, Ke; Bai, Xiang; Leyvand, Tommer; Guo, Baining; Tu, Zhuowen

    2014-07-01

    The launch of Xbox Kinect has built a very successful computer vision product and made a big impact on the gaming industry. This sheds lights onto a wide variety of potential applications related to action recognition. The accurate estimation of human poses from the depth image is universally a critical step. However, existing pose estimation systems exhibit failures when facing severe occlusion. In this paper, we propose an exemplar-based method to learn to correct the initially estimated poses. We learn an inhomogeneous systematic bias by leveraging the exemplar information within a specific human action domain. Furthermore, as an extension, we learn a conditional model by incorporation of pose tags to further increase the accuracy of pose correction. In the experiments, significant improvements on both joint-based skeleton correction and tag prediction are observed over the contemporary approaches, including what is delivered by the current Kinect system. Our experiments for the facial landmark correction also illustrate that our algorithm can improve the accuracy of other detection/estimation systems.

  14. Game-based training environment for nuclear plant control room

    International Nuclear Information System (INIS)

    Nuclear power plant's safety is very important problem. In this very conscientious environment if operator has a little mistake, they may threaten with many people influence their safety. Therefore, operating training of control room is very important. However, the operator training is in limited space and time. Each operator must go to simulative control room do some training. If we can let each trainee having more time to do training and does not go to simulative control room. It may have some advantages for trainee. Moreover, in the traditional training ways, each operator may through the video, teaching manual or through the experienced instructor to learn the knowledge. This training way may let operator feel bored and stressful. So, in this paper aims, we hope utilizing virtual reality technology developing a game-based virtual training environment of control room. Finally, we will use presence questionnaire evaluating realism and feasibility of our virtual training environment. Expecting this initial concept of game-based virtual training environment can attract trainees having more learning motivation to do training in off-hour. (author)

  15. A Web-Based Operating Room Management Educational Tool.

    Science.gov (United States)

    Tsai, Mitchell H; Haddad, Daniel J; Friend, Alexander F; Bender, S Patrick; Davidson, Melissa L

    2016-08-01

    In 2010, our department instituted a nonclinical, administrative rotation in operating room management for anesthesiology residents. Subsequently, we mandated the rotation for all senior anesthesiology residents in 2013. In 2014, under the auspices of the American Society of Anesthesiologists, we developed a web-based module covering the basics of finance, accounting, and operating room management. A multiple-choice test was given to residents at the beginning and end of the rotation, and we compared the mean scores between residents who took the traditional course and residents who took the web-based module. We found no significant difference between the groups of residents, suggesting that the web-based module is as effective as traditional didactics. PMID:27258181

  16. A Web-Based Operating Room Management Educational Tool.

    Science.gov (United States)

    Tsai, Mitchell H; Haddad, Daniel J; Friend, Alexander F; Bender, S Patrick; Davidson, Melissa L

    2016-08-01

    In 2010, our department instituted a nonclinical, administrative rotation in operating room management for anesthesiology residents. Subsequently, we mandated the rotation for all senior anesthesiology residents in 2013. In 2014, under the auspices of the American Society of Anesthesiologists, we developed a web-based module covering the basics of finance, accounting, and operating room management. A multiple-choice test was given to residents at the beginning and end of the rotation, and we compared the mean scores between residents who took the traditional course and residents who took the web-based module. We found no significant difference between the groups of residents, suggesting that the web-based module is as effective as traditional didactics.

  17. Improving room acoustics at low frequencies with multiple loudspeakers and time based room correction

    DEFF Research Database (Denmark)

    Nielsen, Sofus Birkedal; Celestinos, Adrian

    2008-01-01

    frequencies, and appear not only at modal frequencies. The problem is an acoustical issue in time, and should therefore be analyzed in the time-domain, instead of the traditional steady state frequency domain. The construction of a finite-difference time-domain approximation program (FDTD) has lead...... to a simple and untraditional solution called CABS (Controlled Acoustical Bass System) that makes use of multiple loudspeakers. With the proper placement of low frequency loudspeakers, CABS can create a plane wave from the front wall which will be absorbed by additional low frequency loudspeakers at the back...

  18. Room temperature particle detectors based on indium phosphide

    Energy Technology Data Exchange (ETDEWEB)

    Yatskiv, R., E-mail: yatskiv@ufe.c [Institute of Photonics and Electronics, Academy of Sciences of the Czech Republic, Chaberska 57, 18251 Praha 8 (Czech Republic); Grym, J.; Zdansky, K. [Institute of Photonics and Electronics, Academy of Sciences of the Czech Republic, Chaberska 57, 18251 Praha 8 (Czech Republic); Pekarek, L. [Institute of Photonics and Electronics, Academy of Sciences of the Czech Republic, Chaberska 57, 18251 Praha 8 (Czech Republic); Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 18221 Praha 8 (Czech Republic)

    2010-01-01

    A study of electrical properties and detection performance of particle detectors based on bulk InP and semiconducting LPE layers operated at room temperature is presented. Bulk detectors were fabricated on semi-insulating InP crystals grown by liquid-encapsulated Czochralski (LEC) technique. High purity InP layers of both n- and p-type conductivity were used to fabricate detector structures with p-n junction. The detection performance of particle detectors was measured by pulse-height spectra with alpha particles emitted from {sup 241}Am source at room temperature. Better noise properties were achieved for detectors with p-n junctions due to better quality contacts on p-type layers.

  19. Room temperature particle detectors based on indium phosphide

    Science.gov (United States)

    Yatskiv, R.; Grym, J.; Zdansky, K.; Pekarek, L.

    2010-01-01

    A study of electrical properties and detection performance of particle detectors based on bulk InP and semiconducting LPE layers operated at room temperature is presented. Bulk detectors were fabricated on semi-insulating InP crystals grown by liquid-encapsulated Czochralski (LEC) technique. High purity InP layers of both n- and p-type conductivity were used to fabricate detector structures with p-n junction. The detection performance of particle detectors was measured by pulse-height spectra with alpha particles emitted from 241Am source at room temperature. Better noise properties were achieved for detectors with p-n junctions due to better quality contacts on p-type layers.

  20. Room temperature particle detectors based on indium phosphide

    International Nuclear Information System (INIS)

    A study of electrical properties and detection performance of particle detectors based on bulk InP and semiconducting LPE layers operated at room temperature is presented. Bulk detectors were fabricated on semi-insulating InP crystals grown by liquid-encapsulated Czochralski (LEC) technique. High purity InP layers of both n- and p-type conductivity were used to fabricate detector structures with p-n junction. The detection performance of particle detectors was measured by pulse-height spectra with alpha particles emitted from 241Am source at room temperature. Better noise properties were achieved for detectors with p-n junctions due to better quality contacts on p-type layers.

  1. Remote control of magnetostriction-based nanocontacts at room temperature

    Science.gov (United States)

    Jammalamadaka, S. Narayana; Kuntz, Sebastian; Berg, Oliver; Kittler, Wolfram; Kannan, U. Mohanan; Chelvane, J. Arout; Sürgers, Christoph

    2015-09-01

    The remote control of the electrical conductance through nanosized junctions at room temperature will play an important role in future nano-electromechanical systems and electronic devices. This can be achieved by exploiting the magnetostriction effects of ferromagnetic materials. Here we report on the electrical conductance of magnetic nanocontacts obtained from wires of the giant magnetostrictive compound Tb0.3Dy0.7Fe1.95 as an active element in a mechanically controlled break-junction device. The nanocontacts are reproducibly switched at room temperature between “open” (zero conductance) and “closed” (nonzero conductance) states by variation of a magnetic field applied perpendicularly to the long wire axis. Conductance measurements in a magnetic field oriented parallel to the long wire axis exhibit a different behaviour where the conductance switches between both states only in a limited field range close to the coercive field. Investigating the conductance in the regime of electron tunneling by mechanical or magnetostrictive control of the electrode separation enables an estimation of the magnetostriction. The present results pave the way to utilize the material in devices based on nano-electromechanical systems operating at room temperature.

  2. A loudspeaker-based room auralization system for auditory research

    DEFF Research Database (Denmark)

    Favrot, Sylvain Emmanuel

    systematically study the signal processing of realistic sounds by normal-hearing and hearing-impaired listeners, a flexible, reproducible and fully controllable auditory environment is needed. A loudspeaker-based room auralization (LoRA) system was developed in this thesis to provide virtual auditory...... investigated the perception of distance in VAEs generated by the LoRA system. These results showed that the distance of far field sources are similarly perceived in these VAEs as in real environments. For close sources (<1 m), a comprehensive study about the near field compensated HOA method was presented and...

  3. Room temperature ferromagnetism in a phthalocyanine based carbon material

    Energy Technology Data Exchange (ETDEWEB)

    Honda, Z., E-mail: honda@fms.saitama-u.ac.jp; Sato, K.; Sakai, M.; Fukuda, T.; Kamata, N. [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Hagiwara, M.; Kida, T. [KYOKUGEN (Center for Quantum Science and Technology under Extreme Conditions), Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)

    2014-02-07

    We report on a simple method to fabricate a magnetic carbon material that contains nitrogen-coordinated transition metals and has a large magnetic moment. Highly chlorinated iron phthalocyanine was used as building blocks and potassium as a coupling reagent to uniformly disperse nitrogen-coordinated iron atoms on the phthalocyanine based carbon material. The iron phthalocyanine based carbon material exhibits ferromagnetic properties at room temperature and the ferromagnetic phase transition occurs at T{sub c} = 490 ± 10 K. Transmission electron microscopy observation, X-ray diffraction analysis, and the temperature dependence of magnetization suggest that the phthalocyanine molecules form three-dimensional random networks in the iron phthalocyanine based carbon material.

  4. Room Categorization Based on a Hierarchical Representation of Space

    Directory of Open Access Journals (Sweden)

    Peter Uršič

    2013-02-01

    Full Text Available For successful operation in real‐world environments, a mobile robot requires an effective spatial model. The model should be compact, should possess large expressive power and should scale well with respect to the number of modelled categories. In this paper we propose a new compositional hierarchical representation of space that is based on learning statistically significant observations, in terms of the frequency of occurrence of various shapes in the environment. We have focused on a two‐dimensional space, since many robots perceive their surroundings in two dimensions with the use of a laser range finder or sonar. We also propose a new low‐level image descriptor, by which we demonstrate the performance of our representation in the context of a room categorization problem. Using only the lower layers of the hierarchy, we obtain state‐of‐the‐art categorization results in two different experimental scenarios. We also present a large, freely available, dataset, which is intended for room categorization experiments based on data obtained with a laser range finder.

  5. Pulse filtering and correction for CZT detectors using simple digital algorithms based on the wavelet transform

    International Nuclear Information System (INIS)

    The authors report an approach to double gaussian filtering used in classical works as dual parameter pulse processing. This technique has been implemented by creating a bank of gaussian-like digital filters based on wavelet transforms. A simple method to correct for the charge loss inherent to room temperature semiconductor gamma detectors has been developed. This method is based on multi-resolution signal analysis. Results are reported from tests of these algorithms on commercial CZT detectors and two trapped hole charge correction levels are compared. Finally, the advantages and limitations of this new approach to detector pulse processing are discussed

  6. Room-temperature terahertz detection based on CVD graphene transistor

    Institute of Scientific and Technical Information of China (English)

    杨昕昕; 孙建东; 秦华; 吕利; 苏丽娜; 闫博; 李欣幸; 张志鹏; 方靖岳

    2015-01-01

    We report the fabrication and characterization of a single-layer graphene field-effect terahertz detector, which is cou-pled with dipole-like antennas based on the self-mixing detector model. The graphene is grown by chemical vapor deposi-tion and then transferred onto an SiO2/Si substrate. We demonstrate room-temperature detection at 237 GHz. The detector could offer a voltage responsivity of 0.1 V/W and a noise equivalent power of 207 nW/Hz1/2. Our modeling indicates that the observed photovoltage in the p-type gated channel can be well fit by the self-mixing theory. A different photoresponse other than self-mixing may apply for the n-type gated channel.

  7. Loudspeaker-based room auralization in auditory perception research

    DEFF Research Database (Denmark)

    Buchholz, Jörg; Favrot, Sylvain Emmanuel

    2010-01-01

    , and aided-impaired auditory system in realistic environments and (ii) a framework to evaluate the effect of different room modeling and auralisation methods on auditory perception. The applicability of such environment is demonstrated using different objective room acoustic measures. Different experimental...... results are presented, including measures of distance perception and the effect of early reflections on speech intelligibility....

  8. Correction.

    Science.gov (United States)

    2015-11-01

    In the article by Heuslein et al, which published online ahead of print on September 3, 2015 (DOI: 10.1161/ATVBAHA.115.305775), a correction was needed. Brett R. Blackman was added as the penultimate author of the article. The article has been corrected for publication in the November 2015 issue. PMID:26490278

  9. Room Temperature ionic liquids based on asymmetric ammonium salts

    OpenAIRE

    Shaheen, Sobia

    2013-01-01

    Ionic liquids, ILs, in principle, are salts composed of weakly coordinating ions which are liquids at low temperature (˂100 0C). Room temperature ionic liquids, RTILs are those salts which are liquid even at room temperature. Due to the unique properties, such as large liquid range, negligible vapour pressure, solubility of wide range of materials and potential to be recycled and reused, ILs have become a popular class of solvents and catalysts.This study reports the synthesis of a library of...

  10. Straight line feature based image distortion correction

    Institute of Scientific and Technical Information of China (English)

    Zhang Haofeng; Zhao Chunxia; Lu Jianfeng; Tang Zhenmin; Yang Jingyu

    2008-01-01

    An image distortion correction method is proposed, which uses the straight line features. Many parallel lines of different direction from different images were extracted, and then were used to optimize the distortion parameters by nonlinear least square. The thought of step by step was added when the optimization method working. 3D world coordi-nation is not need to know, and the method is easy to implement. The experiment result shows its high accuracy.

  11. Brain Based Instruction in Correctional Settings: Strategies for Teachers.

    Science.gov (United States)

    Becktold, Toni Hill

    2001-01-01

    Brain-based learning strategies (learner choice, movement, small groups) may be inappropriate in corrections for security reasons. Problems encountered in correctional education (attention deficit disorder, learned helplessness) complicate the use of these strategies. Incorporating brain-based instruction in these settings requires creativity and…

  12. High energy sodium based room temperature flow batteries

    Science.gov (United States)

    Shamie, Jack

    As novel energy sources such as solar, wind and tidal energies are explored it becomes necessary to build energy storage facilities to load level the intermittent nature of these energy sources. Energy storage is achieved by converting electrical energy into another form of energy. Batteries have many properties that are attractive for energy storage including high energy and power. Among many different types of batteries, redox flow batteries (RFBs) offer many advantages. Unlike conventional batteries, RFBs store energy in a liquid medium rather than solid active materials. This method of storage allows for the separation of energy and power unlike conventional batteries. Additionally flow batteries may have long lifetimes because there is no expansion or contraction of electrodes. A major disadvantage of RFB's is its lower energy density when compared to traditional batteries. In this Thesis, a novel hybrid Na-based redox flow battery (HNFB) is explored, which utilizes a room temperature molten sodium based anode, a sodium ion conducting solid electrolyte and liquid catholytes. The sodium electrode leads to high voltages and energy and allows for the possibility of multi-electron transfer per molecule. Vanadium acetylacetonate (acac) and TEMPO have been investigated for their use as catholytes. In the vanadium system, 2 electrons transfers per vanadium atom were found leading to a doubling of capacity. In addition, degradation of the charged state was found to be reversible within the voltage range of the cell. Contamination by water leads to the formation of vanadyl acetylacetonate. Although it is believed that vanadyl complex need to be taken to low voltages to be reduced back to vanadium acac, a new mechanism is shown that begins at higher voltages (2.1V). Vanadyl complexes react with excess ligand and protons to reform the vanadium complex. During this reaction, water is reformed leading to the continuous cycle in which vanadyl is formed and then reduced back

  13. Correction.

    Science.gov (United States)

    2016-02-01

    In the article by Guessous et al (Guessous I, Pruijm M, Ponte B, Ackermann D, Ehret G, Ansermot N, Vuistiner P, Staessen J, Gu Y, Paccaud F, Mohaupt M, Vogt B, Pechère-Bertschi A, Martin PY, Burnier M, Eap CB, Bochud M. Associations of ambulatory blood pressure with urinary caffeine and caffeine metabolite excretions. Hypertension. 2015;65:691–696. doi: 10.1161/HYPERTENSIONAHA.114.04512), which published online ahead of print December 8, 2014, and appeared in the March 2015 issue of the journal, a correction was needed.One of the author surnames was misspelled. Antoinette Pechère-Berstchi has been corrected to read Antoinette Pechère-Bertschi.The authors apologize for this error. PMID:26763012

  14. Paper-pen peer-correction versus wiki-based peer-correction

    Directory of Open Access Journals (Sweden)

    Froldova Vladimira

    2016-01-01

    Full Text Available This study reports on the comparison of the students’ achievement and their attitudes towards the use of paper-pen peer-correction and wiki-based peer-correction within English language lessons and CLIL Social Science lessons at the higher secondary school in Prague. Questionnaires and semi-structured interviews were utilized to gather information. The data suggests that students made considerable use of wikis and showed higher degrees of motivation in wiki-based peer-correction during English language lessons than in CLIL Social Science lessons. In both cases wikis not only contributed to developing students’ writing skills, but also helped students recognize the importance of collaboration.

  15. Remote control of magnetostriction-based nanocontacts at room temperature

    OpenAIRE

    S. Narayana Jammalamadaka; Sebastian Kuntz; Oliver Berg; Wolfram Kittler; U. Mohanan Kannan; Arout Chelvane, J.; Christoph Sürgers

    2015-01-01

    The remote control of the electrical conductance through nanosized junctions at room temperature will play an important role in future nano-electromechanical systems and electronic devices. This can be achieved by exploiting the magnetostriction effects of ferromagnetic materials. Here we report on the electrical conductance of magnetic nanocontacts obtained from wires of the giant magnetostrictive compound Tb 0.3 Dy 0.7 Fe 1.95 as an active element in a mechanically controlled break-junction...

  16. Correction

    CERN Multimedia

    2002-01-01

    The photo on the second page of the Bulletin n°48/2002, from 25 November 2002, illustrating the article «Spanish Visit to CERN» was published with a wrong caption. We would like to apologise for this mistake and so publish it again with the correct caption.   The Spanish delegation, accompanied by Spanish scientists at CERN, also visited the LHC superconducting magnet test hall (photo). From left to right: Felix Rodriguez Mateos of CERN LHC Division, Josep Piqué i Camps, Spanish Minister of Science and Technology, César Dopazo, Director-General of CIEMAT (Spanish Research Centre for Energy, Environment and Technology), Juan Antonio Rubio, ETT Division Leader at CERN, Manuel Aguilar-Benitez, Spanish Delegate to Council, Manuel Delfino, IT Division Leader at CERN, and Gonzalo León, Secretary-General of Scientific Policy to the Minister.

  17. Listeners' expectation of room acoustical parameters based on visual cues

    Science.gov (United States)

    Valente, Daniel L.

    Despite many studies investigating auditory spatial impressions in rooms, few have addressed the impact of simultaneous visual cues on localization and the perception of spaciousness. The current research presents an immersive audio-visual study, in which participants are instructed to make spatial congruency and quantity judgments in dynamic cross-modal environments. The results of these psychophysical tests suggest the importance of consilient audio-visual presentation to the legibility of an auditory scene. Several studies have looked into audio-visual interaction in room perception in recent years, but these studies rely on static images, speech signals, or photographs alone to represent the visual scene. Building on these studies, the aim is to propose a testing method that uses monochromatic compositing (blue-screen technique) to position a studio recording of a musical performance in a number of virtual acoustical environments and ask subjects to assess these environments. In the first experiment of the study, video footage was taken from five rooms varying in physical size from a small studio to a small performance hall. Participants were asked to perceptually align two distinct acoustical parameters---early-to-late reverberant energy ratio and reverberation time---of two solo musical performances in five contrasting visual environments according to their expectations of how the room should sound given its visual appearance. In the second experiment in the study, video footage shot from four different listening positions within a general-purpose space was coupled with sounds derived from measured binaural impulse responses (IRs). The relationship between the presented image, sound, and virtual receiver position was examined. It was found that many visual cues caused different perceived events of the acoustic environment. This included the visual attributes of the space in which the performance was located as well as the visual attributes of the performer

  18. Quality Assurance for kV and MV In-room Imaging and Localization for Off- and Online Setup Error Correction

    OpenAIRE

    Balter, James M.; Antonuk, Larry E.

    2008-01-01

    In-room radiography is not a new concept for image guided radiation therapy (IGRT). The rapid advances of technology, however, have made this positioning method convenient, and thus radiograph-based positioning has propagated widely. The paradigms for quality assurance of radiograph-based positioning include imager performance, systems integration, infrastructure, procedure documentation and testing, and support for positioning strategy implementation.

  19. Suboptimal quantum-error-correcting procedure based on semidefinite programming

    OpenAIRE

    Yamamoto, Naoki; Hara, Shinji; Tsumura, Koji

    2006-01-01

    In this paper, we consider a simplified error-correcting problem: for a fixed encoding process, to find a cascade connected quantum channel such that the worst fidelity between the input and the output becomes maximum. With the use of the one-to-one parametrization of quantum channels, a procedure finding a suboptimal error-correcting channel based on a semidefinite programming is proposed. The effectiveness of our method is verified by an example of the bit-flip channel decoding.

  20. Adaptive bad pixel correction algorithm for IRFPA based on PCNN

    Science.gov (United States)

    Leng, Hanbing; Zhou, Zuofeng; Cao, Jianzhong; Yi, Bo; Yan, Aqi; Zhang, Jian

    2013-10-01

    Bad pixels and response non-uniformity are the primary obstacles when IRFPA is used in different thermal imaging systems. The bad pixels of IRFPA include fixed bad pixels and random bad pixels. The former is caused by material or manufacture defect and their positions are always fixed, the latter is caused by temperature drift and their positions are always changing. Traditional radiometric calibration-based bad pixel detection and compensation algorithm is only valid to the fixed bad pixels. Scene-based bad pixel correction algorithm is the effective way to eliminate these two kinds of bad pixels. Currently, the most used scene-based bad pixel correction algorithm is based on adaptive median filter (AMF). In this algorithm, bad pixels are regarded as image noise and then be replaced by filtered value. However, missed correction and false correction often happens when AMF is used to handle complex infrared scenes. To solve this problem, a new adaptive bad pixel correction algorithm based on pulse coupled neural networks (PCNN) is proposed. Potential bad pixels are detected by PCNN in the first step, then image sequences are used periodically to confirm the real bad pixels and exclude the false one, finally bad pixels are replaced by the filtered result. With the real infrared images obtained from a camera, the experiment results show the effectiveness of the proposed algorithm.

  1. Graphene-based room-temperature implementation of a modified Deutsch-Jozsa quantum algorithm.

    Science.gov (United States)

    Dragoman, Daniela; Dragoman, Mircea

    2015-12-01

    We present an implementation of a one-qubit and two-qubit modified Deutsch-Jozsa quantum algorithm based on graphene ballistic devices working at room temperature. The modified Deutsch-Jozsa algorithm decides whether a function, equivalent to the effect of an energy potential distribution on the wave function of ballistic charge carriers, is constant or not, without measuring the output wave function. The function need not be Boolean. Simulations confirm that the algorithm works properly, opening the way toward quantum computing at room temperature based on the same clean-room technologies as those used for fabrication of very-large-scale integrated circuits. PMID:26541203

  2. Static beacons based indoor positioning method for improving room-level accuracy

    OpenAIRE

    Miekk-oja, Ville

    2015-01-01

    Demand for indoor positioning applications has been growing lately. Indoor positioning is used for example in hospitals for patient tracking, and in airports for finding correct gates. Requirements in indoor positioning have become more strict with demands for a higher accuracy. This thesis presents a method for improving the room-level accuracy of a positioning system by using static beacons. As a static beacon, Bluetooth low energy modules will be used to test how much they can improve...

  3. Selfishness- and Selflessness-based models of pedestrian room evacuation

    Science.gov (United States)

    Song, Xiao; Ma, Liang; Ma, Yaofei; Yang, Chen; Ji, Hang

    2016-04-01

    Some pedestrian evacuation studies have employed game strategy to deal with moving conflicts involving two or three pedestrians. However, most of these have simply presented game strategies for pedestrians without analyzing the reasons why they choose to defect or cooperate. We believe that selfish and selfless behaviors are two main factors that should be considered in evacuation. In addition to these behaviors, human emotions such as sympathy and behaviors such as vying were also taken into account to investigate their impacts on pedestrians' strategies. Moreover, an essential objective factor, the building design factor of door width was tested and analyzed. Experimental results showed that the sense of self leads to more defectors and a longer evacuation time. However, sympathy does some good, leading to more cooperators and a shorter evacuation time. Moreover, the exit door width is an essential factor of the evacuation efficiency. When the width was less than 6 cells in a rectangular room with a size greater than 50 × 50, the evacuation time greatly decreased when the width increased. However, this effect was less obvious when the width increased.

  4. Room-temperature single-photon sources based on nanocrystal fluorescence in photonic/plasmonic nanostructures

    Science.gov (United States)

    Lukishova, S. G.; Winkler, J. M.; Bissell, L. J.; Mihaylova, D.; Liapis, Andreas C.; Shi, Z.; Goldberg, D.; Menon, V. M.; Boyd, R. W.; Chen, G.; Prasad, P.

    2014-10-01

    Results are presented here towards robust room-temperature SPSs based on fluorescence in nanocrystals: colloidal quantum dots, color-center diamonds and doped with trivalent rare-earth ions (TR3+). We used cholesteric chiral photonic bandgap and Bragg-reflector microcavities for single emitter fluorescence enhancement. We also developed plasmonic bowtie nanoantennas and 2D-Si-photonic bandgap microcavities. The paper also provides short outlines of other technologies for room-temperature single-photon sources.

  5. CT-based attenuation and scatter correction compared with uniform attenuation correction in brain perfusion SPECT imaging for dementia

    Science.gov (United States)

    Gillen, Rebecca; Firbank, Michael J.; Lloyd, Jim; O'Brien, John T.

    2015-09-01

    This study investigated if the appearance and diagnostic accuracy of HMPAO brain perfusion SPECT images could be improved by using CT-based attenuation and scatter correction compared with the uniform attenuation correction method. A cohort of subjects who were clinically categorized as Alzheimer’s Disease (n=38 ), Dementia with Lewy Bodies (n=29 ) or healthy normal controls (n=30 ), underwent SPECT imaging with Tc-99m HMPAO and a separate CT scan. The SPECT images were processed using: (a) correction map derived from the subject’s CT scan or (b) the Chang uniform approximation for correction or (c) no attenuation correction. Images were visually inspected. The ratios between key regions of interest known to be affected or spared in each condition were calculated for each correction method, and the differences between these ratios were evaluated. The images produced using the different corrections were noted to be visually different. However, ROI analysis found similar statistically significant differences between control and dementia groups and between AD and DLB groups regardless of the correction map used. We did not identify an improvement in diagnostic accuracy in images which were corrected using CT-based attenuation and scatter correction, compared with those corrected using a uniform correction map.

  6. AC dipole based optics measurement and correction at RHIC

    CERN Document Server

    Shen, X; Bai, M; White, S; Robert-Domolaize, G; Luo, Y; Marusic, A; Tomas, R

    2013-01-01

    Independent component analysis (ICA) was applied to the AC dipole based optics measurement at RHIC to extract beta functions as well as phase advances at each BPM. Existence of excessive beta-beat was observed in both rings of RHIC at polarized proton store energy. A unique global optics correction scheme was then developed and tested successfully during the RHIC polarized proton run in 2013. The feasibility of using horizontal closed orbit bump at sextupole for arc beta-beat correction was also demonstrated.

  7. Multiple Base Substitution Corrections in DNA Sequence Evolution

    Science.gov (United States)

    Kowalczuk, M.; Mackiewicz, P.; Szczepanik, D.; Nowicka, A.; Dudkiewicz, M.; Dudek, M. R.; Cebrat, S.

    We discuss the Jukes and Cantor's one-parameter model and Kimura's two-parameter model unability to describe evolution of asymmetric DNA molecules. The standard distance measure between two DNA sequences, which is the number of substitutions per site, should include the effect of multiple base substitutions separately for each type of the base. Otherwise, the respective tables of substitutions cannot reconstruct the asymmetric DNA molecule with respect to the composition. Basing on Kimura's neutral theory, we have derived a linear law for the correlation of the mean survival time of nucleotides under constant mutation pressure and their fraction in the genome. According to the law, the corrections to Kimura's theory have been discussed to describe evolution of genomes with asymmetric nucleotide composition. We consider the particular case of the strongly asymmetric Borrelia burgdorferi genome and we discuss in detail the corrections, which should be introduced into the distance measure between two DNA sequences to include multiple base substitutions.

  8. Heterodyne detection with mismatch correction base on array detector

    Science.gov (United States)

    Hongzhou, Dong; Guoqiang, Li; Ruofu, Yang; Chunping, Yang; Mingwu, Ao

    2016-07-01

    Based on an array detector, a new heterodyne detection system, which can correct the mismatches of amplitude and phase between signal and local oscillation (LO) beams, is presented in this paper. In the light of the fact that, for a heterodyne signal, there is a certain phase difference between the adjacent two samples of analog-to-digital converter (ADC), we propose to correct the spatial phase mismatch by use of the time-domain phase difference. The corrections can be realized by shifting the output sequences acquired from the detector elements in the array, and the steps of the shifting depend on the quantity of spatial phase mismatch. Numerical calculations of heterodyne efficiency are conducted to confirm the excellent performance of our system. Being different from previous works, our system needs not extra optical devices, so it provides probably an effective means to ease the problem resulted from the mismatches.

  9. Heterodyne detection with mismatch correction based on array detector

    Science.gov (United States)

    Dong, Hongzhou; Li, Guoqiang; Yang, Ruofu; Yang, Chunping; Ao, Mingwu

    2016-07-01

    Based on an array detector, a new heterodyne detection system, which can correct the mismatches of amplitude and phase between signal and local oscillation (LO) beams, is presented in this paper. In the light of the fact that, for a heterodyne signal, there is a certain phase difference between the adjacent two samples of analog-to-digital converter (ADC), we propose to correct the spatial phase mismatch by use of the time-domain phase difference. The corrections can be realized by shifting the output sequences acquired from the detector elements in the array, and the steps of the shifting depend on the quantity of spatial phase mismatch. Numerical calculations of heterodyne efficiency are conducted to confirm the excellent performance of our system. Being different from previous works, our system needs not extra optical devices, so it provides probably an effective means to ease the problem resulted from the mismatches.

  10. Ising Spin-Based Error Correcting Private-Key Cryptosystems

    Institute of Scientific and Technical Information of China (English)

    ZHENG Dong; ZHENG Yan-fei; FAN Wu-ying

    2006-01-01

    Ising spin system has been shown to provide a new class of error-correction code and can be used to construct public-key cryptosystems by making use of statistical mechanics. The relation between Ising spin systems and private-key cryptosystems are investigated. Two private-key systems are based on two predetermined randomly constructed sparse matrices and rely on exploiting physical properties of the Mackay-Neal (MN) low-density parity-check (LDPC) error-correcting codes are proposed. One is error correcting private-key system, which is powerful to combat ciphertext errors in communications and computer systems. The other is a private-key system with authentication.

  11. MR-based Motion Correction for PET Imaging

    Science.gov (United States)

    Ouyang, Jinsong; Li, Quanzheng; Fakhri, Georges El

    2012-01-01

    PET image quality is limited by patient motion. Emission data are blurred due to cardiac and/or respiratory motion. Although spatial resolution is 4 mm for standard clinical whole-body PET scanners, the effective resolution can be a low as 1 cm due to motion. Additionally, the deformation of attenuation medium causes image artifacts. Previously, gating is used to “freeze” the motion, but leads to significantly increased noise level. Simultaneous PET-MR modality offers a new way to perform PET motion correction. MR can be used to measure 3D motion fields, which can then be incorporated into the iterative PET reconstruction to obtain motion corrected PET images. In this report, we present MR imaging techniques to acquire dynamic images, a non-rigid image registration algorithm to extract motion fields from acquired MR images, and a PET reconstruction algorithm with motion correction. We also present results from both phantom and in-vivo animal PET-MR studies. We demonstrate that MR-based PET motion correction using simultaneous PET-MR improves image quality and lesion detectability compared to gating and to no motion correction. PMID:23178089

  12. Applications of knowledge-based systems in NPP control rooms

    International Nuclear Information System (INIS)

    The proper functioning of the nuclear power plant operator as an information processor and decision maker is crucial for performance reliability. The application of knowledge-based systems offers new possibilities for supporting the operator and reducing the complexity of the system representation. This is particularly important under difficult conditions where his performance might otherwise deteriorate. Such applications include improved alarm analysis, operations tracking and monitoring, and a flexible handling of the operator-system dialogue. The paper will characterise the range of applications as well as report on the development of a specific system. This uses several knowledge-based systems to support the operator by making the required operation less knowledge intensive. (author)

  13. Room Categorization Based on a Hierarchical Representation of Space

    OpenAIRE

    Peter Uršič; Domen Tabernik; Marko Boben; Danijel Skočaj; Aleš Leonardis; Matej Kristan

    2013-01-01

    For successful operation in real‐world environments, a mobile robot requires an effective spatial model. The model should be compact, should possess large expressive power and should scale well with respect to the number of modelled categories. In this paper we propose a new compositional hierarchical representation of space that is based on learning statistically significant observations, in terms of the frequency of occurrence of various shapes in the environment. We have focused on a two‐d...

  14. Condition-based Human Reliability Assessment for digitalized control room

    Energy Technology Data Exchange (ETDEWEB)

    Kang, H. G.; Jang, S. C.; Eom, H. S.; Ha, J. J

    2005-04-01

    In safety-critical systems, the generation failure of an actuation signal is caused by the concurrent failures of the automated systems and an operator action. These two sources of safety signals are complicatedly correlated. The failures of sensors or automated systems will cause a lack of necessary information for a human operator and result in error-forcing contexts such as the loss of corresponding alarms and indications. In the conventional analysis, the Human Error Probabilities (HEP) are estimated based on the assumption of 'normal condition of indications and alarms'. In order to construct a more realistic signal-generation failure model, we have to consider more complicated conditions in a more realistic manner. In this study, we performed two kinds of investigation for addressing this issue. We performed the analytic calculations for estimating the effect of sensors failures on the system unavailability and plant risk. For the single-parameter safety signals, the analysis result reveals that the quantification of the HEP should be performed by focusing on the 'no alarm from the automatic system and corresponding indications unavailable' situation. This study also proposes a Condition-Based Human Reliability Assessment (CBHRA) method in order to address these complicated conditions in a practical way. We apply the CBHRA method to the manual actuation of the safety features such as a reactor trip and auxiliary feedwater actuation in Korean Standard Nuclear Power Plants. In the case of conventional single HEP method, it is very hard to consider the multiple HE conditions. The merit of CBHRA is clearly shown in the application to the AFAS generation where no dominating HE condition exits. In this case, even if the HE conditions are carefully investigated, the single HEP method cannot accommodate the multiple conditions in a fault tree. On the other hand, the application result of the reactor trip in SLOCA shows that if there is a

  15. Optimization-based mesh correction with volume and convexity constraints

    Science.gov (United States)

    D'Elia, Marta; Ridzal, Denis; Peterson, Kara J.; Bochev, Pavel; Shashkov, Mikhail

    2016-05-01

    We consider the problem of finding a mesh such that 1) it is the closest, with respect to a suitable metric, to a given source mesh having the same connectivity, and 2) the volumes of its cells match a set of prescribed positive values that are not necessarily equal to the cell volumes in the source mesh. This volume correction problem arises in important simulation contexts, such as satisfying a discrete geometric conservation law and solving transport equations by incremental remapping or similar semi-Lagrangian transport schemes. In this paper we formulate volume correction as a constrained optimization problem in which the distance to the source mesh defines an optimization objective, while the prescribed cell volumes, mesh validity and/or cell convexity specify the constraints. We solve this problem numerically using a sequential quadratic programming (SQP) method whose performance scales with the mesh size. To achieve scalable performance we develop a specialized multigrid-based preconditioner for optimality systems that arise in the application of the SQP method to the volume correction problem. Numerical examples illustrate the importance of volume correction, and showcase the accuracy, robustness and scalability of our approach.

  16. Development of a plastic rotary heat exchanger for room-based ventilation in existing apartments

    DEFF Research Database (Denmark)

    Smith, Kevin Michael; Svendsen, Svend

    2015-01-01

    The existing building stock will likely undergo widespread energy renovations to meet future emissions targets. Single-room ventilation may enable the process due to its simple installation, low fan power, and potential for local heat recovery. A short plastic rotary heat exchanger is developed...... for single-room ventilation based on thermal design theory. Performance is predicted from correlations of dimensionless groups for regenerative heat exchangers, and this guides the selection of a polycarbonate honeycomb with small circular channels. Experiments quantify flows and determine temperature...

  17. Activity-based costing in the operating room at Valley View Hospital.

    Science.gov (United States)

    Baker, J J; Boyd, G F

    1997-01-01

    This article presents an example of how one hospital reports the results of activity-based costing (ABC). It examines the composition and supporting assumptions of an ABC report for a particular procedure in the operating room (OR). It describes management uses of the information generated. It comments upon how the continuous quality improvement (CQI) is synchronized with the ABC reporting. PMID:9327354

  18. Room-temperature base-free copper-catalyzed trifluoromethylation of organotrifluoroborates to trifluoromethylarenes

    KAUST Repository

    Huang, Yuanyuan

    2012-12-01

    An efficient room temperature copper-catalyzed trifluoromethylation of organotrifluoroborates under the base free condition using an electrophilic trifluoromethylating reagent is demonstrated. The corresponding trifluoromethylarenes were obtained in good to excellent yields and the reaction tolerates a wide range of functional groups. © 2012 Elsevier Ltd. All rights reserved.

  19. Activity-based costing in the operating room at Valley View Hospital.

    Science.gov (United States)

    Baker, J J; Boyd, G F

    1997-01-01

    This article presents an example of how one hospital reports the results of activity-based costing (ABC). It examines the composition and supporting assumptions of an ABC report for a particular procedure in the operating room (OR). It describes management uses of the information generated. It comments upon how the continuous quality improvement (CQI) is synchronized with the ABC reporting.

  20. Correction of Misclassifications Using a Proximity-Based Estimation Method

    Science.gov (United States)

    Niemistö, Antti; Shmulevich, Ilya; Lukin, Vladimir V.; Dolia, Alexander N.; Yli-Harja, Olli

    2004-12-01

    An estimation method for correcting misclassifications in signal and image processing is presented. The method is based on the use of context-based (temporal or spatial) information in a sliding-window fashion. The classes can be purely nominal, that is, an ordering of the classes is not required. The method employs nonlinear operations based on class proximities defined by a proximity matrix. Two case studies are presented. In the first, the proposed method is applied to one-dimensional signals for processing data that are obtained by a musical key-finding algorithm. In the second, the estimation method is applied to two-dimensional signals for correction of misclassifications in images. In the first case study, the proximity matrix employed by the estimation method follows directly from music perception studies, whereas in the second case study, the optimal proximity matrix is obtained with genetic algorithms as the learning rule in a training-based optimization framework. Simulation results are presented in both case studies and the degree of improvement in classification accuracy that is obtained by the proposed method is assessed statistically using Kappa analysis.

  1. Correction of Misclassifications Using a Proximity-Based Estimation Method

    Directory of Open Access Journals (Sweden)

    Shmulevich Ilya

    2004-01-01

    Full Text Available An estimation method for correcting misclassifications in signal and image processing is presented. The method is based on the use of context-based (temporal or spatial information in a sliding-window fashion. The classes can be purely nominal, that is, an ordering of the classes is not required. The method employs nonlinear operations based on class proximities defined by a proximity matrix. Two case studies are presented. In the first, the proposed method is applied to one-dimensional signals for processing data that are obtained by a musical key-finding algorithm. In the second, the estimation method is applied to two-dimensional signals for correction of misclassifications in images. In the first case study, the proximity matrix employed by the estimation method follows directly from music perception studies, whereas in the second case study, the optimal proximity matrix is obtained with genetic algorithms as the learning rule in a training-based optimization framework. Simulation results are presented in both case studies and the degree of improvement in classification accuracy that is obtained by the proposed method is assessed statistically using Kappa analysis.

  2. Tls Field Data Based Intensity Correction for Forest Environments

    Science.gov (United States)

    Heinzel, J.; Huber, M. O.

    2016-06-01

    Terrestrial laser scanning (TLS) is increasingly used for forestry applications. Besides the three dimensional point coordinates, the 'intensity' of the reflected signal plays an important role in forestry and vegetation studies. The benefit of the signal intensity is caused by the wavelength of the laser that is within the near infrared (NIR) for most scanners. The NIR is highly indicative for various vegetation characteristics. However, the intensity as recorded by most terrestrial scanners is distorted by both external and scanner specific factors. Since details about system internal alteration of the signal are often unknown to the user, model driven approaches are impractical. On the other hand, existing data driven calibration procedures require laborious acquisition of separate reference datasets or areas of homogenous reflection characteristics from the field data. In order to fill this gap, the present study introduces an approach to correct unwanted intensity variations directly from the point cloud of the field data. The focus is on the variation over range and sensor specific distortions. Instead of an absolute calibration of the values, a relative correction within the dataset is sufficient for most forestry applications. Finally, a method similar to time series detrending is presented with the only pre-condition of a relative equal distribution of forest objects and materials over range. Our test data covers 50 terrestrial scans captured with a FARO Focus 3D S120 scanner using a laser wavelength of 905 nm. Practical tests demonstrate that our correction method removes range and scanner based alterations of the intensity.

  3. Ground-Based Correction of Remote-Sensing Spectral Imagery

    Science.gov (United States)

    Alder-Golden, Steven M.; Rochford, Peter; Matthew, Michael; Berk, Alexander

    2007-01-01

    Software has been developed for an improved method of correcting for the atmospheric optical effects (primarily, effects of aerosols and water vapor) in spectral images of the surface of the Earth acquired by airborne and spaceborne remote-sensing instruments. In this method, the variables needed for the corrections are extracted from the readings of a radiometer located on the ground in the vicinity of the scene of interest. The software includes algorithms that analyze measurement data acquired from a shadow-band radiometer. These algorithms are based on a prior radiation transport software model, called MODTRAN, that has been developed through several versions up to what are now known as MODTRAN4 and MODTRAN5 . These components have been integrated with a user-friendly Interactive Data Language (IDL) front end and an advanced version of MODTRAN4. Software tools for handling general data formats, performing a Langley-type calibration, and generating an output file of retrieved atmospheric parameters for use in another atmospheric-correction computer program known as FLAASH have also been incorporated into the present soft-ware. Concomitantly with the soft-ware described thus far, there has been developed a version of FLAASH that utilizes the retrieved atmospheric parameters to process spectral image data.

  4. In vitro mechanical properties comparsion of four room temperature curing denture base resin:

    Institute of Scientific and Technical Information of China (English)

    LI Zhian; XIA Xuetong; Xiao Qun

    2001-01-01

    @@ The room temperature curing denture base resin has low mechanical properties,so it was limited in clinical application. It had previously disscused that reinfored maehinical properties with metal fiber, glass fiber,plastic fiber and by adding the fracture resistance substances in powderThe aim of this study was to determined the mechanical properities of four roomtemperature curing denture base resin which had been modified performance withhigh boil point methacrylate.

  5. Time based room correction system for low frequencies using multiple loudspeakers

    DEFF Research Database (Denmark)

    Nielsen, Sofus Birkedal; Celestinos, Adrian

    2007-01-01

    -domain by the construction of a finite-difference time-domain approximation program (FDTD) has lead to a novel and simple solution also working in the time-domain called Controlled Acoustically Bass System (CABS). Working in the time-domain CABS includes additional cancelling loudspeakers at the back wall in order to remove...... from scratch for further development of CABS....

  6. Warped document image correction method based on heterogeneous registration strategies

    Science.gov (United States)

    Tong, Lijing; Zhan, Guoliang; Peng, Quanyao; Li, Yang; Li, Yifan

    2013-03-01

    With the popularity of digital camera and the application requirement of digitalized document images, using digital cameras to digitalize document images has become an irresistible trend. However, the warping of the document surface impacts on the quality of the Optical Character Recognition (OCR) system seriously. To improve the warped document image's vision quality and the OCR rate, this paper proposed a warped document image correction method based on heterogeneous registration strategies. This method mosaics two warped images of the same document from different viewpoints. Firstly, two feature points are selected from one image. Then the two feature points are registered in the other image base on heterogeneous registration strategies. At last, image mosaics are done for the two images, and the best mosaiced image is selected by OCR recognition results. As a result, for the best mosaiced image, the distortions are mostly removed and the OCR results are improved markedly. Experimental results show that the proposed method can resolve the issue of warped document image correction more effectively.

  7. EPICS based control system of pulse bend correction coil

    International Nuclear Information System (INIS)

    The pulse-bend magnet in J-PARC 3-50BT has the residual magnetic field, slightly after it has sent protons to MR. Due to this effect, we can not supply protons to the MLF, during three 25Hz-cycles. A correction coil and its custom made power-supply were introduced in order to cancel out the residual magnetic field. We have constructed an EPICS-based control systems for this correction coil power supply. The control system have four components: (1) a PLC controller with a Linux CPU and I/O modules, (2) a commercial function generator, (3) a custom made power-supply to drive coil current, and (4) a timing module to provide proper trigger signals. A pattern waveform, delivered from a function generator, is used to drives the customized power supply. We have examined basic functionalities of the control system during beam studies in May and in June 2014, and confirmed its availabilities, namely status monitoring and operation controls. However, we found some problems in interlock signals of the power-supply. We will improve the system toward the next operation from this autumn. (author)

  8. ITM-Based FSI-Models for Rooms with Absorptive Boundaries

    OpenAIRE

    Buchschmid, Martin

    2012-01-01

    A method for room acoustical simulations has been developed in order to compute the sound field in acoustic cavities with compound absorbers, mounted at the walls. To reduce the number of degrees of freedom and therefore the numerical effort, a model reduction method, based on a Component Mode Synthesis (CMS), is applied. Macrostructures are assembled out of single substructures applying shape functions at the interfaces. These substructures contain acoustic components like porous absorbers o...

  9. Coding design for error correcting output codes based on perceptron

    Science.gov (United States)

    Zhou, Jin-Deng; Wang, Xiao-Dan; Zhou, Hong-Jian; Cui, Yong-Hua; Jing, Sun

    2012-05-01

    It is known that error-correcting output codes (ECOC) is a common way to model multiclass classification problems, in which the research of encoding based on data is attracting more and more attention. We propose a method for learning ECOC with the help of a single-layered perception neural network. To achieve this goal, the code elements of ECOC are mapped to the weights of network for the given decoding strategy, and an object function with the constrained weights is used as a cost function of network. After the training, we can obtain a coding matrix including lots of subgroups of class. Experimental results on artificial data and University of California Irvine with logistic linear classifier and support vector machine as the binary learner show that our scheme provides better performance of classification with shorter length of coding matrix than other state-of-the-art encoding strategies.

  10. Evolutionary modeling-based approach for model errors correction

    Science.gov (United States)

    Wan, S. Q.; He, W. P.; Wang, L.; Jiang, W.; Zhang, W.

    2012-08-01

    The inverse problem of using the information of historical data to estimate model errors is one of the science frontier research topics. In this study, we investigate such a problem using the classic Lorenz (1963) equation as a prediction model and the Lorenz equation with a periodic evolutionary function as an accurate representation of reality to generate "observational data." On the basis of the intelligent features of evolutionary modeling (EM), including self-organization, self-adaptive and self-learning, the dynamic information contained in the historical data can be identified and extracted by computer automatically. Thereby, a new approach is proposed to estimate model errors based on EM in the present paper. Numerical tests demonstrate the ability of the new approach to correct model structural errors. In fact, it can actualize the combination of the statistics and dynamics to certain extent.

  11. Multirobot FastSLAM Algorithm Based on Landmark Consistency Correction

    Directory of Open Access Journals (Sweden)

    Shi-Ming Chen

    2014-01-01

    Full Text Available Considering the influence of uncertain map information on multirobot SLAM problem, a multirobot FastSLAM algorithm based on landmark consistency correction is proposed. Firstly, electromagnetism-like mechanism is introduced to the resampling procedure in single-robot FastSLAM, where we assume that each sampling particle is looked at as a charged electron and attraction-repulsion mechanism in electromagnetism field is used to simulate interactive force between the particles to improve the distribution of particles. Secondly, when multiple robots observe the same landmarks, every robot is regarded as one node and Kalman-Consensus Filter is proposed to update landmark information, which further improves the accuracy of localization and mapping. Finally, the simulation results show that the algorithm is suitable and effective.

  12. Evolutionary modeling-based approach for model errors correction

    Directory of Open Access Journals (Sweden)

    S. Q. Wan

    2012-08-01

    Full Text Available The inverse problem of using the information of historical data to estimate model errors is one of the science frontier research topics. In this study, we investigate such a problem using the classic Lorenz (1963 equation as a prediction model and the Lorenz equation with a periodic evolutionary function as an accurate representation of reality to generate "observational data."

    On the basis of the intelligent features of evolutionary modeling (EM, including self-organization, self-adaptive and self-learning, the dynamic information contained in the historical data can be identified and extracted by computer automatically. Thereby, a new approach is proposed to estimate model errors based on EM in the present paper. Numerical tests demonstrate the ability of the new approach to correct model structural errors. In fact, it can actualize the combination of the statistics and dynamics to certain extent.

  13. A highly reversible room-temperature lithium metal battery based on crosslinked hairy nanoparticles.

    KAUST Repository

    Choudhury, Snehashis

    2015-12-04

    Rough electrodeposition, uncontrolled parasitic side-reactions with electrolytes and dendrite-induced short-circuits have hindered development of advanced energy storage technologies based on metallic lithium, sodium and aluminium electrodes. Solid polymer electrolytes and nanoparticle-polymer composites have shown promise as candidates to suppress lithium dendrite growth, but the challenge of simultaneously maintaining high mechanical strength and high ionic conductivity at room temperature has so far been unmet in these materials. Here we report a facile and scalable method of fabricating tough, freestanding membranes that combine the best attributes of solid polymers, nanocomposites and gel-polymer electrolytes. Hairy nanoparticles are employed as multifunctional nodes for polymer crosslinking, which produces mechanically robust membranes that are exceptionally effective in inhibiting dendrite growth in a lithium metal battery. The membranes are also reported to enable stable cycling of lithium batteries paired with conventional intercalating cathodes. Our findings appear to provide an important step towards room-temperature dendrite-free batteries.

  14. Room-Temperature NH3 Gas Sensor Based on Hydrothermally Grown ZnO Nanorods

    Institute of Scientific and Technical Information of China (English)

    WEI Ang; WANG Zhao; PAN Liu-Hua; LI Wei-Wei; XIONG Li; DONG Xiao-Chen; HUANG Wei

    2011-01-01

    @@ A NH3 gas sensor based on a ZnO nanorod array is fabricated by hydrothermal decomposition on a Au electrode.The as-grown ZnO nanorods have uniform diameter distribution and good crystal structure,shown by scanning electron microscopy,x-ray diffraction,high resolution transmission electron microscopy and photoluminescence emission characterizations.The gas sensing results show that the ZnO nanorod-based device responds well to ammonia gas at room temperature(sensitivity S is about 8).

  15. Does evidence-based health care have room for the self?

    Science.gov (United States)

    Thomas, S Joshua

    2016-08-01

    Evidence-based health care (EBHC) has consistently been attacked by opponents for being perniciously reductive. Although these attacks are overwhelmingly framed as critiques of evidence-based medicine, they standardly target the research wing of EBHC upon which evidence-based medicine is dependent, and increasingly extend to adjacent health care disciplines, such as nursing. One of the most persistent forms this line of attack has taken is the allegation that EBHC, with its emphasis on the hierarchy of evidence, grounded in the use of randomized controlled trials, and the clinical guidelines developed on their basis, fails to recognize the patient as the complex self she is, treating her instead as merely a quantifiable, medical-scientific object. By reducing the patient to certain quantifiable dimensions, the patient as self is allegedly 'erased'. In short, the complaint is that an evidence-based approach to health care has no room for the self. Contrary to this persistently held view, it is argued here that EBHC does have room for the self. Review of these critiques suggests they can be categorized into two groups: soft critiques and strong critiques. Soft critiques tend to take a more measured tone grounded in empirical concerns about the dangers of an evidence-based approach to health care, whereas strong critiques tend to make sweeping claims grounded in theoretical commitments to anti-foundationalist philosophical frameworks. While both soft and strong critiques ultimately fail to make the case that EBHC has no room for the self, the empirical concerns of soft critiques nevertheless present a challenge EBHC advocates would do well to take seriously and address.

  16. Accuracy Improvement Capability of Advanced Projectile Based on Course Correction Fuze Concept

    Directory of Open Access Journals (Sweden)

    Ahmed Elsaadany

    2014-01-01

    Full Text Available Improvement in terminal accuracy is an important objective for future artillery projectiles. Generally it is often associated with range extension. Various concepts and modifications are proposed to correct the range and drift of artillery projectile like course correction fuze. The course correction fuze concepts could provide an attractive and cost-effective solution for munitions accuracy improvement. In this paper, the trajectory correction has been obtained using two kinds of course correction modules, one is devoted to range correction (drag ring brake and the second is devoted to drift correction (canard based-correction fuze. The course correction modules have been characterized by aerodynamic computations and flight dynamic investigations in order to analyze the effects on deflection of the projectile aerodynamic parameters. The simulation results show that the impact accuracy of a conventional projectile using these course correction modules can be improved. The drag ring brake is found to be highly capable for range correction. The deploying of the drag brake in early stage of trajectory results in large range correction. The correction occasion time can be predefined depending on required correction of range. On the other hand, the canard based-correction fuze is found to have a higher effect on the projectile drift by modifying its roll rate. In addition, the canard extension induces a high-frequency incidence angle as canards reciprocate at the roll motion.

  17. Control room design and human factors using a virtual reality based tool for design, test and training

    International Nuclear Information System (INIS)

    This report describes a user-centred approach to control room design adopted by IFE for the nuclear industry. The novelty of this approach is the development of a Control Room Philosophy, and the use of Virtual Reality (VR) technology as a tool in the design process, integrated with a specially developed Design Documentation System (DDS) and a process display prototyping tool PICASSO-3. The control room philosophy identifies all functional aspects of a control centre, to define the baseline principles and guidelines for the design. The use of VR technology enables end-users of the control room design (e.g. control room operators) to specify their preferred design of the new control room, and to replace the need for a physical mock-up to test and evaluate the proposed design. The DDS, integrated with the VR design tool, guides the control room operators, through a structured approach, to document the proposed design in a complete design specification. The VR tool, specially developed by IFE, is called the VR based Design, Test and Training tool (VR DTandT). It is not only intended to visualise the design, but also to test and evaluate the design. When the design is implemented, the same model is re-used as a VR based training simulator for operators. A special feature in the VR DTandT tool is that the verification and validation (VandV) tests, concerning human factors, are according to the regulative standards for nuclear control rooms

  18. Beam-Based Nonlinear Optics Corrections in Colliders

    CERN Document Server

    Pilat, Fulvia Caterina; Malitsky, Nikolay; Ptitsyn, Vadim

    2005-01-01

    A method has been developed to measure and correct operationally the non-linear effects of the final focusing magnets in colliders, which gives access to the effects of multi-pole errors by applying closed orbit bumps, and analyzing the resulting tune and orbit shifts. This technique has been tested and used during 3 years of RHIC (the Relativistic Heavy Ion Collider at BNL) operations. I will discuss here the theoretical basis of the method, the experimental set-up, the correction results, the present understanding of the machine model, the potential and limitations of the method itself as compared with other non linear correction techniques.

  19. Ge-Based Spin-Photodiodes for Room-Temperature Integrated Detection of Photon Helicity

    KAUST Repository

    Rinaldi, Christian

    2012-05-02

    Spin-photodiodes based on Fe/MgO/Ge(001) heterostructures are reported. These devices perform the room-temperature integrated electrical detection of the spin polarization of a photocurrent generated by circularly polarized photons with a wavelength of 1300 nm, for light pulses with intensity I 0 down to 200 μW. A forward and reverse-biased average photocurrent variation of 5.9% is measured for the complete reversal of the incident light helicity. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Resistor array infrared nonuniformity correction based on sparse grid

    Science.gov (United States)

    He, Xudong; Qiu, Jiang; Zhang, Qiao; Du, Huijie; Zhao, Hongming

    2013-10-01

    Resistor array plays a vital role in emulation of the IR control and guide system. However, its serious nonuniformity confines the range of its application. Therefore, in order to obtain an available IR image, nonuniformity correction (NUC) is necessary. The traditional method is sparse grid and flood which only take the array's nonuniformity into account. In this paper we present an improved sparse grid method which considers the whole system which affects the array's nonuniformity by dividing the NUC process into different gray levels. In each gray level, we can take two points or several points to calculate the nonuniformity of every block which is divided before correction. After that, we can have several characteristic curves which will be operated with curve fitting. By this means, we will correct the nonuniformity. At last, through the experiment of a number of images, we find the residual nonuniformity associated with random noise is about 0.2% after the correction.

  1. Room temperature deformation of in-situ grown quasicrystals embedded in Al-based cast alloy

    Directory of Open Access Journals (Sweden)

    Boštjan Markoli

    2013-12-01

    Full Text Available An Al-based cast alloy containing Mn, Be and Cu has been chosen to investigate the room temperature deformation behavior of QC particles embedded in Al-matrix. Using LOM, SEM (equipped with EDS, conventional TEM with SAED and controlled tensile and compression tests, the deformation response of AlMn2Be2Cu2 cast alloy at room temperature has been examined. Alloy consisted of Al-based matrix, primary particles and eutectic icosahedral quasicrystalline (QC i-phase and traces of Θ-Al2Cu and Al10Mn3. Tensile and compression specimens were used for evaluation of mechanical response and behavior of QC i-phase articles embedded in Al-cast alloy. It has been established that embedded QC i-phase particles undergo plastic deformation along with the Al-based matrix even under severe deformation and have the response resembling that of the metallic materials by formation of typical cup-and-cone feature prior to failure. So, we can conclude that QC i-phase has the ability to undergo plastic deformation along with the Al-matrix to greater extent contrary to e.g. intermetallics such as Θ-Al2Cu for instance.

  2. Room Volume Estimation Based on Ambiguity of Short-Term Interaural Phase Differences Using Humanoid Robot Head

    Directory of Open Access Journals (Sweden)

    Ryuichi Shimoyama

    2016-07-01

    Full Text Available Humans can recognize approximate room size using only binaural audition. However, sound reverberation is not negligible in most environments. The reverberation causes temporal fluctuations in the short-term interaural phase differences (IPDs of sound pressure. This study proposes a novel method for a binaural humanoid robot head to estimate room volume. The method is based on the statistical properties of the short-term IPDs of sound pressure. The humanoid robot turns its head toward a sound source, recognizes the sound source, and then estimates the ego-centric distance by its stereovision. By interpolating the relations between room volume, average standard deviation, and ego-centric distance experimentally obtained for various rooms in a prepared database, the room volume was estimated by the binaural audition of the robot from the average standard deviation of the short-term IPDs at the estimated distance.

  3. Human factor engineering based design and modernization of control rooms with new I and C systems

    International Nuclear Information System (INIS)

    Instrumentation and Control (I and C) systems of the latest nuclear power plants are based on the use of digital technology, distributed control systems and the integration of information in data networks (Distributed Control and Instrumentation Systems). This has a repercussion on Control Rooms (CRs), where the operations and monitoring interfaces correspond to these systems. These technologies are also used in modernizing I and C systems in currently operative nuclear power plants. The new interfaces provide additional capabilities for operation and supervision, as well as a high degree of flexibility, versatility and reliability. An example of this is the implementation of solutions such as compact stations, high level supervision screens, overview displays, computerized procedures, new operational support systems or intelligent alarms processing systems in the modernized Man-Machine Interface (MMI). These changes in the MMI are accompanied by newly added Software (SW) controls and new solutions in automation. Tecnatom has been leading various projects in this area for several years, both in Asian countries and in the United States, using in all cases international standards from which Tecnatom own methodologies have been developed and optimized. The experience acquired in applying this methodology to the design of new control rooms is to a large extent applicable also to the modernization of current control rooms. An adequate design of the interface between the operator and the systems will facilitate safe operation, contribute to the prompt identification of problems and help in the distribution of tasks and communications between the different members of the operating shift. Based on Tecnatom experience in the field, this article presents the methodological approach used as well as the most relevant aspects of this kind of project. (authors)

  4. A Short Study To Evaluate Effectiveness Of Class Room Teaching Versus Community Based Learning Among Medical Students.

    OpenAIRE

    Dr. L. Kannan; Dr. Praveena. P

    2015-01-01

    Back ground Class room teaching was previously pronounced as Didactic lecture most commonly performed in teaching and learning methods to cover a vast portion of the syllabus in medical curriculum1. There is a need of community based approach in understanding the concepts and practice which is a lacuna in the syllabus that has to be addressed in the curriculum 2. Hence the study is done to evaluate the effectiveness of Class room teaching Didactic lecture versus Community based learning amon...

  5. Scene-based nonuniformity correction based on bilateral filter with reduced ghosting

    Science.gov (United States)

    Li, Zhaolong; Shen, Tongsheng; Lou, Shuli

    2016-07-01

    In order to correct the nonuniformity noise of the IR imaging system, a nonuniformity correction deghosting algorithm based on high-brightness region detection was proposed. Firstly, the bilateral filter was used to filter the image. The high-brightness regions in the result image were detected, and the correction factors corresponding to the regions were reduced. And then, the positions were detected which are high-brightness pixels in former frame but are not in current frame, and the correction factors corresponding to the regions were enlarged. Thus, the wrong update of the correction factor caused by high-brightness region of both the current frame and the previous frame was reduced. The correction method was validated using a real image sequence. The experimental results showed that the suppression effect of the proposed algorithm on the 'ghost' effect caused by the high-brightness region is better than the other two algorithms named SLTH-NUC and BFTH-NUC, respectively. Moreover, the proposed algorithm can also suppress the 'ghost' effect caused by the sharp edge of the scene.

  6. Magnetoresistance effect in rubrene-based spin valves at room temperature.

    Science.gov (United States)

    Zhang, Xianmin; Ma, Qinli; Suzuki, Kazuya; Sugihara, Atsushi; Qin, Gaowu; Miyazaki, Terunobu; Mizukami, Shigemi

    2015-03-01

    We fabricate spin-valve devices with an Fe3O4/AlO/rubrene/Co stacking structure. Their magnetoresistance (MR) effects at room temperature and low temperatures are systemically investigated based on the measurement of MR curves, current-voltage response, etc. A large MR ratio of approximately 6% is achieved at room temperature, which is one of the highest MR ratios reported to date in organic spin valves. With decreasing measurement temperatures, we observe that the MR ratios increase because of decrease in spin scattering, and the width of the MR curves becomes larger owing to increase in the coercivity of the electrodes at low temperature. A nonlinear current-voltage dependence is clearly observed in these organic spin valves. From the measurement of MR curve for the spin valves with different rubrene layer thickness, we observe that the MR ratios monotonously decrease with increasing rubrene-layer thickness. We discuss the spin-dependent transport mechanisms in these devices based on our experimental results and the present theoretical analysis. Moreover, we note that the devices exhibit smaller MR ratios after annealing compared to their counterparts without annealing. On the basis of atomic force microscopy analysis of the organic films and device resistances, we deduce that the increase of interface spin scattering induced by large surface roughness after annealing most probably leads to reduction in the MR ratios. PMID:25668508

  7. Correction of oral contrast artifacts in CT-based attenuation correction of PET images using an automated segmentation algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Ahmadian, Alireza; Ay, Mohammad R.; Sarkar, Saeed [Medical Sciences/University of Tehran, Research Center for Science and Technology in Medicine, Tehran (Iran); Medical Sciences/University of Tehran, Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran (Iran); Bidgoli, Javad H. [Medical Sciences/University of Tehran, Research Center for Science and Technology in Medicine, Tehran (Iran); East Tehran Azad University, Department of Electrical and Computer Engineering, Tehran (Iran); Zaidi, Habib [Geneva University Hospital, Division of Nuclear Medicine, Geneva (Switzerland)

    2008-10-15

    Oral contrast is usually administered in most X-ray computed tomography (CT) examinations of the abdomen and the pelvis as it allows more accurate identification of the bowel and facilitates the interpretation of abdominal and pelvic CT studies. However, the misclassification of contrast medium with high-density bone in CT-based attenuation correction (CTAC) is known to generate artifacts in the attenuation map ({mu}map), thus resulting in overcorrection for attenuation of positron emission tomography (PET) images. In this study, we developed an automated algorithm for segmentation and classification of regions containing oral contrast medium to correct for artifacts in CT-attenuation-corrected PET images using the segmented contrast correction (SCC) algorithm. The proposed algorithm consists of two steps: first, high CT number object segmentation using combined region- and boundary-based segmentation and second, object classification to bone and contrast agent using a knowledge-based nonlinear fuzzy classifier. Thereafter, the CT numbers of pixels belonging to the region classified as contrast medium are substituted with their equivalent effective bone CT numbers using the SCC algorithm. The generated CT images are then down-sampled followed by Gaussian smoothing to match the resolution of PET images. A piecewise calibration curve was then used to convert CT pixel values to linear attenuation coefficients at 511 keV. The visual assessment of segmented regions performed by an experienced radiologist confirmed the accuracy of the segmentation and classification algorithms for delineation of contrast-enhanced regions in clinical CT images. The quantitative analysis of generated {mu}maps of 21 clinical CT colonoscopy datasets showed an overestimation ranging between 24.4% and 37.3% in the 3D-classified regions depending on their volume and the concentration of contrast medium. Two PET/CT studies known to be problematic demonstrated the applicability of the technique

  8. Combining Trigram-based and Feature-based Methods for Context-Sensitive Spelling Correction

    CERN Document Server

    Golding, A R; Golding, Andrew R.; Schabes, Yves

    1996-01-01

    This paper addresses the problem of correcting spelling errors that result in valid, though unintended words (such as ``peace'' and ``piece'', or ``quiet'' and ``quite'') and also the problem of correcting particular word usage errors (such as ``amount'' and ``number'', or ``among'' and ``between''). Such corrections require contextual information and are not handled by conventional spelling programs such as Unix `spell'. First, we introduce a method called Trigrams that uses part-of-speech trigrams to encode the context. This method uses a small number of parameters compared to previous methods based on word trigrams. However, it is effectively unable to distinguish among words that have the same part of speech. For this case, an alternative feature-based method called Bayes performs better; but Bayes is less effective than Trigrams when the distinction among words depends on syntactic constraints. A hybrid method called Tribayes is then introduced that combines the best of the previous two methods. The impr...

  9. Indium oxide octahedrons based on sol–gel process enhance room temperature gas sensing performance

    International Nuclear Information System (INIS)

    Highlights: • In2O3 octahedron films are prepared based on sol–gel technique for the first time. • The preparation possesses merits of low temperature, catalyst-free and large production. • It was found that the spin-coating process in film fabrication was key to achieve the octahedrons. • The In2O3 octahedrons could significantly enhance room temperature NO2 gas sensing performance. - Abstract: Indium oxide octahedrons were prepared on glass substrates through a mild route based on sol–gel technique. The preparation possesses characteristics including low temperature, catalyst-free and large production, which is much distinguished from the chemical-vapor-deposition based methods that usually applied to prepare indium oxide octahedrons. Detailed characterization revealed that the indium oxide octahedrons were single crystalline, with {1 1 1} crystal facets exposed. It was found that the spin-coating technique was key for achieving the indium oxide crystals with octahedron morphology. The probable formation mechanism of the indium oxide octahedrons was proposed based on the experiment results. Room temperature NO2 gas sensing measurements exhibited that the indium oxide octahedrons could significantly enhance the sensing performance in comparison with the plate-like indium oxide particles that prepared from the dip-coated gel films, which was attributed to the abundant sharp edges and tips as well as the special {1 1 1} crystal facets exposed that the former possessed. Such a simple wet-chemical based method to prepare indium oxide octahedrons with large-scale production is promising to provide the advanced materials that can be applied in wide fields like gas sensing, solar energy conversion, field emission, and so on

  10. High Power, Room Temperature Terahertz Emitters Based on Dopant Transitions in 6H-Silicon Carbide

    Institute of Scientific and Technical Information of China (English)

    James Kolodzey; Guang-Chi Xuan; Peng-Cheng Lv; Nathan Sustersic; Xin Ma

    2014-01-01

    Electrically pumped high power terahertz (THz) emitters that operated above room temperature in a pulse mode were fabricated from nitrogen-doped n-type 6H-SiC. The emission spectra had peaks centered on 5 THz and 12 THz (20 meV and 50 meV) that were attributed to radiative transitions of excitons bound to nitrogen donor impurities. Due to the relatively deep binding energies of the nitrogen donors, above 100 meV, and the high thermal conductivity of the SiC substrates, the THz output power and operating temperature were significantly higher than previous dopant based emitters. With peak applied currents of a few amperes, and a top surface area of 1 mm2, the device emitted up to 0.5 mW at liquid nitrogen temperature (77 K), and tens of microwatts up to 333 K. This result is the highest temperature of THz emission reported from impurity-based emitters.

  11. Supporting Online Video-Based Correction for Language Learning through Markup-Based Video Editing.

    Science.gov (United States)

    Hada, Yoshiaki; Ogata, Hiroaki; Yano, Yoneo

    This paper focuses on an online video based correction system for language learning. The prototype system using the proposed model supports learning between a native English teacher and a non-native learner using a videoconference system. It extends the videoconference system so that it can record the conversation of a learning scene. If a teacher…

  12. Immobilization and Bioelectrochemistry of Hemoglobin Based on Carrageenan and Room Temperature Ionic Liquid Composite Film

    Institute of Scientific and Technical Information of China (English)

    盛春; 张洋; 王璐; 贾能勤

    2012-01-01

    A novel biopolymer/room-temperature ionic liquid composite film based on carrageenan, room temperature ionic liquid (IL) [1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4)] was explored for immobilization of hemoglobin (Hb) and construction of biosensor. Direct electrochemistry and electrocatalytic behaviors of Hb entrapped in the IL-carrageenan composite film on the surface of glassy carbon electrode (GCE) were investigated. UV-vis spectroscopy demonstrated that Hb in the IL-carrageenan composite film could retain its native secondary structure. A pair of well-defined redox peaks of Hb was obtained at the Hb-IL-carrageenan composite film modified electrode through direct electron transfer between the protein and the underlying electrode. The heterogeneous electron transfer rate constant (ks) was 2.02 s 1, indicating great facilitation of the electron transfer between Hb and IL-carrageenan composite film modified electrode. The modified electrode showed excellent electrocatalytic activity toward reduction of hydrogen peroxide with a linear range of 5.0 × 10-6 to 1.5 ×10-4 mol/L and the detection limit was 2.12 ×10 7 mol/L (S/N= 3). The apparent Michaelis-Menten constant KM^app for hydrogen peroxide was estimated to be 0.02 mmol/L, indicating that the biosensor possessed high affinity to hydrogen peroxide. In addition, the proposed biosensor showed good reproducibility and stability.

  13. Improved batch correction in untargeted MS-based metabolomics

    NARCIS (Netherlands)

    Wehrens, Ron; Hageman, Jos A.; Eeuwijk, van Fred; Kooke, Rik; Flood, Pádraic J.; Wijnker, Erik; Keurentjes, Joost J.B.; Lommen, Arjen; Eekelen, van Henriëtte D.L.M.; Hall, Robert D.; Mumm, Roland; Vos, de Ric C.H.

    2016-01-01

    Introduction: Batch effects in large untargeted metabolomics experiments are almost unavoidable, especially when sensitive detection techniques like mass spectrometry (MS) are employed. In order to obtain peak intensities that are comparable across all batches, corrections need to be performed. S

  14. Correcting CIV-Based Virial Black Hole Masses

    CERN Document Server

    Coatman, Liam; Banerji, Manda; Richards, Gordon T; Hennawi, Joseph F; Prochaska, J Xavier

    2016-01-01

    The CIV broad emission line is visible in optical spectra to redshifts exceeding z~5. CIV has long been known to exhibit significant displacements to the blue and these `blueshifts' almost certainly signal the presence of strong outflows. As a consequence, single-epoch virial black hole (BH) mass estimates derived from CIV velocity-widths are known to be systematically biased compared to masses from the hydrogen Balmer lines. Using a large sample of 230 high-luminosity (log $L_{\\rm Bol}$ = 45.5-48 erg/s), redshift 1.55000 km/s. Using the monotonically increasing relationship between the CIV blueshift and the mass ratio BH(CIV)/BH(H$\\alpha$) we derive an empirical correction to all CIV BH-masses. The scatter between the corrected CIV masses and the Balmer masses is 0.24 dex at low CIV blueshifts (~0 km/s) and just 0.10 dex at high blueshifts (~3000 km/s), compared to 0.40 dex before the correction. The correction depends only on the CIV line properties - i.e. full-width at half maximum and blueshift - and can ...

  15. Diamond based light-emitting diode for visible single-photon emission at room temperature

    Science.gov (United States)

    Lohrmann, A.; Pezzagna, S.; Dobrinets, I.; Spinicelli, P.; Jacques, V.; Roch, J.-F.; Meijer, J.; Zaitsev, A. M.

    2011-12-01

    Diamond-based p-i-n light-emitting diodes capable of single-photon emission in the visible spectral region at room temperature are discussed. The diodes were fabricated on a high quality single crystal diamond grown by chemical vapor deposition. Implantation of boron and phosphorus ions followed by annealing at a temperature of 1600 °C has been used for doping p-type and n-type areas, respectively. Electrical characterization of the devices demonstrates clear diode behavior. Spectra of electroluminescence generated in the i-area reveal sole emission from the neutral nitrogen-vacancy (NV) defects. Photon antibunching implies single-photon character of this emission when generated by individual NV defects.

  16. Safe in the city: developing an effective video-based intervention for STD clinic waiting rooms.

    Science.gov (United States)

    Myint-U, Athi; Bull, Sheana; Greenwood, Gregory L; Patterson, Jocelyn; Rietmeijer, Cornelis A; Vrungos, Shelley; Warner, Lee; Moss, Jesse; O'Donnell, Lydia N

    2010-05-01

    There is a strong need for inexpensive, easily administered HIV and STD prevention interventions that are highly replicable and appealing to diverse clinic audiences. This article describes the four-step iterative and collaborative process used by the Safe City Study Group to design and develop a brief video-based intervention: Safe in the City. Step 1 involves identification of an appropriate intervention medium, a theoretical framework, and key messages; Step 2, collaboration with a film company to integrate the framework and key messages into an entertaining product; Step 3, facilitation of a multistep participatory process involving input from members of the priority audience (clinic patients), clinic staff, and community reviewers; and Step 4, pilot-testing to determine structural barriers to patients' viewing the video in clinic waiting rooms. Safe in the City has been demonstrated to reduce incident STDs among clinic patients in three cities in the United States.

  17. A Cucurbit[7]uril Based Molecular Shuttle Encoded by Visible Room-Temperature Phosphorescence.

    Science.gov (United States)

    Gong, Yifan; Chen, Hui; Ma, Xiang; Tian, He

    2016-06-17

    A visible room-temperature phosphorescence (RTP) signal, generated by complexation of cururbit[7]uril (CB[7]) and bromo-substituted isoquinoline in aqueous solution, is employed to address the shuttling of a pH-controlling molecular shuttle fabricated by CB[7] and a phosphor 6-bromoisoquinoline derivative IQC[5]. The CB[7] host shuttles along the axial guest under acidic conditions, accompanied by a weak RTP emission signal, while deprotonation of the guest IQC[5] makes the CB[7] wheel locate on the phosphor group, leading to intense RTP emission. The switching RTP emission of the molecular shuttle, via pH adjusting, can be visibly identified by the naked eye. This is the first CB-based molecular shuttle with an RTP signal as the output address of its shuttling and conformation. PMID:26548653

  18. Ultrafast and sensitive room temperature NH3 gas sensors based on chemically reduced graphene oxide

    Science.gov (United States)

    Hu, Nantao; Yang, Zhi; Wang, Yanyan; Zhang, Liling; Wang, Ying; Huang, Xiaolu; Wei, Hao; Wei, Liangmin; Zhang, Yafei

    2014-01-01

    Ultrafast and sensitive room temperature NH3 gas sensors based on chemically reduced graphene oxide (rGO) are demonstrated in this work. rGO, which was prepared via the reduction of graphene oxide by pyrrole, exhibited excellent responsive sensitivity and selectivity to ammonia (NH3) gas. The high sensing performance of these rGO sensors with resistance change as high as 2.4% and response time as fast as 1.4 s was realized when the concentration of NH3 gas was as low as 1 ppb. Furthermore, the rGO sensors could rapidly recover to their initial states with IR illumination. The devices also showed excellent repeatability and selectivity to NH3. These rGO sensors, with low cost, low power, and easy fabrication, as well as scalable properties, showed great potential for ultrasensitive detection of NH3 gas in a wide variety of fields.

  19. Enhanced and selective ammonia sensing of reduced graphene oxide based chemo resistive sensor at room temperature

    Science.gov (United States)

    Kumar, Ramesh; Kaur, Amarjeet

    2016-05-01

    The reduced graphene oxide thin films were fabricated by using the spin coating method. The reduced graphene oxide samples were characterised by Raman studies to obtain corresponding D and G bands at 1360 and 1590 cm-1 respectively. Fourier transform infra-red (FTIR) spectra consists of peak corresponds to sp2 hybridisation of carbon atoms at 1560 cm-1. The reduced graphene oxide based chemoresistive sensor exhibited a p-type semiconductor behaviour in ambient conditions and showed good sensitivity to different concentration of ammonia from 25 ppm to 500 ppm and excellent selectivity at room temperature. The sensor displays selectivity to several hazardous vapours such as methanol, ethanol, acetone and hydrazine hydrate. The sensor demonstrated a sensitivity of 9.8 at 25 ppm concentration of ammonia with response time of 163 seconds.

  20. Fission-Product Separation Based on Room-Temperature Ionic Liquids. Final Report

    International Nuclear Information System (INIS)

    During previous DOE sponsored research (DE-FG07-01ER63286), a process was developed for removing Cs+ and Sr2+ from simulated aqueous tank waste by extraction of these ions into a hydrophobic room-temperature ionic liquid solvent, tri-n-butylmethylammonium bis((trifluoromethyl)sulfonyl)imide, containing the ionophores, calix(4)arene-bis(tert-octylbenzo-crown-6) and dicyclohexano-18-crown-6. The coordinated Cs+ and Sr2+ could be removed from the ionic liquid extraction solvent by an electrochemical reduction process carried out at mercury electrodes. In this follow-up project, the effects of residual moisture and oxygen on this processing scheme were assessed. It was determined that the electrochemical reduction of ionophore-bound Cs+ at Hg electrodes is surprisingly tolerant of small amounts of water, but greatly affected by oxygen. However, sparging of the ionic liquid with dry N2 lowers the residual water and oxygen content of the extraction solvent to the level where the reduction of Cs+ at Hg is possible. Thus, the entire treatment cycle for the removal of Cs+ from tank waste using this approach can be carried out in an open cell, provided that the cell is continuously sparged with dry N2. (Due to a reduction in the funds designated for the project, it was not possible to investigate the effects of moisture and oxygen on the Sr2+ removal process.) Additional research carried out under this project led to the discovery and characterization of a new low-melting urea-based melt that can be used as an electrochemical solvent. This melt is less expensive to prepare than most of the well-know room-temperature ionic liquid solvents, has a better electrochemical window than existing urea-based melts, and has potential applications for the processing of nuclear waste. This melt is made by combining urea with the N,N-dialkylimidazolium salt, 1-ethyl-3-methylimidazolium chloride.

  1. A theoretical approach to room acoustic simulations based on a radiative transfer model

    DEFF Research Database (Denmark)

    Ruiz-Navarro, Juan-Miguel; Jacobsen, Finn; Escolano, José;

    2010-01-01

    by incorporating a propagation medium that absorbs and scatters radiation, handling both diffuse and non-diffuse reflections on boundaries and objects in the room. The main scope of this model is to provide a proper foundation for a wide number of room acoustic simulation models, in order to establish and unify...... their principles. It is shown that this room acoustic modeling technique establishes the basis of two recently proposed algorithms, the acoustic diffusion equation and the room acoustic rendering equation. Both methods are derived in detail using an analytical approximation and a simplified integral equation...

  2. Reasons for Faith-Based Correctional Program Participation: An Examination of Motive Types

    Science.gov (United States)

    Kwon, Okyun; Camp, Scott D.; Daggett, Dawn M.; Klein-Saffran, Jody

    2010-01-01

    Although faith-based correctional programming has become increasingly popular in recent years, offenders' motivation to participate and the impact on prison adjustment have received little attention. Analyzing interview data of 83 participants of the Federal Bureau of Prison's faith-based correctional program, this study explored the different…

  3. 19 CFR 142.50 - Line Release data base corrections or changes.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Line Release data base corrections or changes. 142...; DEPARTMENT OF THE TREASURY (CONTINUED) ENTRY PROCESS Line Release § 142.50 Line Release data base corrections... numbers or bond information on a Line Release Data Loading Sheet as soon as possible. Notification...

  4. A fuel cell operating between room temperature and 250 C based on a new phosphoric acid based composite electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Rong [Department of Chemistry, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Xu, Xiaoxiang; Irvine, John T.S. [School of Chemistry, University of St Andrews, St Andrews, Fife KY16 9ST (United Kingdom); Tao, Shanwen [Department of Chemistry, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); School of Chemistry, University of St Andrews, St Andrews, Fife KY16 9ST (United Kingdom)

    2010-10-15

    A phosphoric acid based composite material with core-shell microstructure has been developed to be used as a new electrolyte for fuel cells. A fuel cell based on this electrolyte can operate at room temperature indicating leaching of H{sub 3}PO{sub 4} with liquid water is insignificant at room temperature. This will help to improve the thermal cyclability of phosphoric acid based electrolyte to make it easier for practical use. The conductivity of this H{sub 3}PO{sub 4}-based electrolyte is stable at 250 C with addition of the hydrophilic inorganic compound BPO{sub 4} forming a core-shell microstructure which makes it possible to run a PAFC at a temperature above 200 C. The core-shell microstructure retains after the fuel cell measurements. A power density of 350 mW/cm{sup 2} for a H{sub 2}/O{sub 2} fuel cell has been achieved at 200 C. The increase in operating temperature does not have significant benefit to the performance of a H{sub 2}/O{sub 2} fuel cell. For the first time, a composite electrolyte material for phosphoric acid fuel cells which can operate in a wide range of temperature has been evaluated but certainly further investigation is required. (author)

  5. Explaining the Relation between Nutrition and Room Temperature Based on Iranian Medicine

    Science.gov (United States)

    Moradi, Hossein

    2016-01-01

    Background: Nutrition is one of the most effective components of human’s health and nutritional practices have an important role in a healthy nutrition. Iranian traditional medicine, which is one of the holistic medical schools, has special approaches related to effective environmental factors in healthy nutrition. Identifying these special approaches is helpful to the medical community. The aim of this study was to examine the relation between nutrition and room temperature during different seasons based on Iranian traditional medicine. To that end, its precise scientific aspects and the approach of the traditional medicine practitioners was analyzed to provide a new pattern in nutrition with respect to the weather Methods: Traditional medicine literature including Ibn-e Sina’s Qanoon, Zakhirey-e Kharazm shahi, Kāmil al-Sinaā al Tibbiya al-Maliki, mofarreh al-gholoob, Hefz o sehe Naseri, were studied. Differences and similarities were reviewed and summarized. In order to analyze the data, scientific resources of modern medicine such as Krause’s food and nutrition principles were applied. Results: According to traditional medicine’s approaches and the new scientific findings, there are significant differences between the type of regime, quality, and quantity of meals during different seasons of a year and in different room temperatures. Considering the above-mentioned differences, it plays an important role in a healthy nutrition. Conclusion: Adhering to a good regime and vigilance on a healthy nutrition would provide a new pattern regime and ultimately lead to healthy people. Therefore, it is important to focus on this topic to promote a healthy society.

  6. Improving Accuracy and Simplifying Training in Fingerprinting-Based Indoor Location Algorithms at Room Level

    Directory of Open Access Journals (Sweden)

    Mario Muñoz-Organero

    2016-01-01

    Full Text Available Fingerprinting-based algorithms are popular in indoor location systems based on mobile devices. Comparing the RSSI (Received Signal Strength Indicator from different radio wave transmitters, such as Wi-Fi access points, with prerecorded fingerprints from located points (using different artificial intelligence algorithms, fingerprinting-based systems can locate unknown points with a few meters resolution. However, training the system with already located fingerprints tends to be an expensive task both in time and in resources, especially if large areas are to be considered. Moreover, the decision algorithms tend to be of high memory and CPU consuming in such cases and so does the required time for obtaining the estimated location for a new fingerprint. In this paper, we study, propose, and validate a way to select the locations for the training fingerprints which reduces the amount of required points while improving the accuracy of the algorithms when locating points at room level resolution. We present a comparison of different artificial intelligence decision algorithms and select those with better results. We do a comparison with other systems in the literature and draw conclusions about the improvements obtained in our proposal. Moreover, some techniques such as filtering nonstable access points for improving accuracy are introduced, studied, and validated.

  7. Thermal properties in phase change wallboard room based on air conditioning cold storage

    Institute of Scientific and Technical Information of China (English)

    陈其针; 刘鑫; 牛润萍; 王琳

    2009-01-01

    By comparing the thermal performance parameters of an ordinary wall room with a phase change wall (PCW) room,the effect of phase change wallboard on the fluctuation of temperature in air-conditioning room in summer was studied. And PCW room and an ordinary wall room,which are cooled by air-conditioner,were built up. Differential scanning calorimetry (DSC) was used to test the temperature field and heat flow fluctuation in these rooms. Through analyzing the data tested,it is found that the mean temperature of PCW is lower than that of ordinary wall room by 1-2 ℃,and PCW can lower the heat flow by 4.6 W/m2. Combining phase change material to building envelope can lower the indoor temperature,make the room thermal comfortable,and cut down the turn-on-and-off frequency of air-conditioner,the primary investment and operating costs. It alleviates urgent need of the electric power. Building envelope which contains phase change wallboard can improve the indoor thermal environment,and decrease energy consumption in buildings. Phase change wallboard can make impressive effect on energy efficiency of buildings.

  8. Correcting scan-to-scan response variability for a radiochromic film-based reference dosimetry system

    International Nuclear Information System (INIS)

    Purpose: In radiochromic film dosimetry systems, measurements are usually obtained from film images acquired on a CCD-based flatbed scanner. The authors investigated factors affecting scan-to-scan response variability leading to increased dose measurement uncertainty. Methods: The authors used flatbed document scanners to repetitively scan EBT3 radiochromic films exposed to doses 0–1000 cGy, together with three neutral density filters and three blue optical filters. Scanning was performed under two conditions: scanner lid closed and scanner lid opened/closed between scans. The authors also placed a scanner in a cold room at 9 °C and later in a room at 22 °C and scanned EBT3 films to explore temperature effects. Finally, the authors investigated the effect of altering the distance between the film and the scanner’s light source. Results: Using a measurement protocol to isolate the contribution of the CCD and electronic circuitry of the scanners, the authors found that the standard deviation of response measurements for the EBT3 film model was about 0.17% for one scanner and 0.09% for the second. When the lid of the first scanner was opened and closed between scans, the average scan-to-scan difference of responses increased from 0.12% to 0.27%. Increasing the sample temperature during scanning changed the RGB response values by about −0.17, −0.14, and −0.05%/°C, respectively. Reducing the film-to-light source distance increased the RBG response values about 1.1, 1.3, and 1.4%/mm, respectively. The authors observed that films and film samples were often not flat with some areas up to 8 mm away from the scanner’s glass window. Conclusions: In the absence of measures to deal with the response irregularities, each factor the authors investigated could lead to dose uncertainty >2%. Those factors related to the film-to-light source distance could be particularly impactful since the authors observed many instances where the curl of film samples had the

  9. Unique Room Temperature Light Emitting Diode Based on 2D Hybrid Organic-Inorganic Low Dimensional Perovskite Semiconductor

    CERN Document Server

    Vassilakopoulou, Anastasia; Koutselas, Ioannis

    2016-01-01

    Room temperature single layer light emitting diode(LED), based on a two dimensional hybrid organic-inorganic semiconductor(HOIS), is demonstrated. This simple, low cost excitonic LED operates at low voltages. Such an excitonic device is presented for the first time as functioning at room temperature. The newly introduced class of perovskite LEDs, until now based on 3D perovksite HOIS, is now broadened with the implementation of the 2D HOIS. Novel functionalities can be realized since it is now possible to access the hybrid's 2D semiconductor advantageous properties, such as the increased excitonic peak wavelength tunability, excitonic binding energy and oscillator strength.

  10. Ion transport and structural dynamics in homologous ammonium and phosphonium-based room temperature ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Philip J., E-mail: pgrif@seas.upenn.edu [Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Holt, Adam P. [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States); Tsunashima, Katsuhiko [Department of Materials Science, National Institute of Technology, Wakayama College, 77 Noshima, Nada-cho, Gobo, Wakayama 644-0023 (Japan); Sangoro, Joshua R. [Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Kremer, Friedrich [Institute of Experimental Physics I, University of Leipzig, Linnestr. 5, 04103 Leipzig (Germany); Sokolov, Alexei P. [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States); Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996 (United States); Chemical Sciences Division, Oak Ridge National Lab, Oak Ridge, Tennessee 37830 (United States)

    2015-02-28

    Charge transport and structural dynamics in a homologous pair of ammonium and phosphonium based room temperature ionic liquids (ILs) have been characterized over a wide temperature range using broadband dielectric spectroscopy and quasi-elastic light scattering spectroscopy. We have found that the ionic conductivity of the phosphonium based IL is significantly enhanced relative to the ammonium homolog, and this increase is primarily a result of a lower glass transition temperature and higher ion mobility. Additionally, these ILs exhibit pronounced secondary relaxations which are strongly influenced by the atomic identity of the cation charge center. While the secondary relaxation in the phosphonium IL has the expected Arrhenius temperature dependence characteristic of local beta relaxations, the corresponding relaxation process in the ammonium IL was found to exhibit a mildly non-Arrhenius temperature dependence in the measured temperature range—indicative of molecular cooperativity. These differences in both local and long-range molecular dynamics are a direct reflection of the subtly different inter-ionic interactions and mesoscale structures found in these homologous ILs.

  11. Hypoxia Room

    Data.gov (United States)

    Federal Laboratory Consortium — The Hypoxia Room is a 8x8x8 ft. clear vinyl plastic and aluminum frame construction enclosure located within USAREIM laboratory 028. The Hypoxia Room (manufactured...

  12. Field of view extension and truncation correction for MR-based human attenuation correction in simultaneous MR/PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Blumhagen, Jan O., E-mail: janole.blumhagen@siemens.com; Ladebeck, Ralf; Fenchel, Matthias [Magnetic Resonance, Siemens AG Healthcare Sector, Erlangen 91052 (Germany); Braun, Harald; Quick, Harald H. [Institute of Medical Physics, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen 91052 (Germany); Faul, David [Siemens Medical Solutions, New York, New York 10015 (United States); Scheffler, Klaus [MRC Department, Max Planck Institute for Biological Cybernetics, Tübingen 72076, Germany and Department of Biomedical Magnetic Resonance, University Hospital Tübingen, Tübingen 72076 (Germany)

    2014-02-15

    Purpose: In quantitative PET imaging, it is critical to accurately measure and compensate for the attenuation of the photons absorbed in the tissue. While in PET/CT the linear attenuation coefficients can be easily determined from a low-dose CT-based transmission scan, in whole-body MR/PET the computation of the linear attenuation coefficients is based on the MR data. However, a constraint of the MR-based attenuation correction (AC) is the MR-inherent field-of-view (FoV) limitation due to static magnetic field (B{sub 0}) inhomogeneities and gradient nonlinearities. Therefore, the MR-based human AC map may be truncated or geometrically distorted toward the edges of the FoV and, consequently, the PET reconstruction with MR-based AC may be biased. This is especially of impact laterally where the patient arms rest beside the body and are not fully considered. Methods: A method is proposed to extend the MR FoV by determining an optimal readout gradient field which locally compensates B{sub 0} inhomogeneities and gradient nonlinearities. This technique was used to reduce truncation in AC maps of 12 patients, and the impact on the PET quantification was analyzed and compared to truncated data without applying the FoV extension and additionally to an established approach of PET-based FoV extension. Results: The truncation artifacts in the MR-based AC maps were successfully reduced in all patients, and the mean body volume was thereby increased by 5.4%. In some cases large patient-dependent changes in SUV of up to 30% were observed in individual lesions when compared to the standard truncated attenuation map. Conclusions: The proposed technique successfully extends the MR FoV in MR-based attenuation correction and shows an improvement of PET quantification in whole-body MR/PET hybrid imaging. In comparison to the PET-based completion of the truncated body contour, the proposed method is also applicable to specialized PET tracers with little uptake in the arms and might

  13. Low frequency sound field control in rectangular listening rooms using CABS (Controlled Acoustic Bass System) will also reduce sound transmission to neighbor rooms

    DEFF Research Database (Denmark)

    Nielsen, Sofus Birkedal; Celestinos, Adrian

    2011-01-01

    Sound reproduction is often taking place in small and medium sized rectangular rooms. As rectangular rooms have 3 pairs of parallel walls the reflections at especially low frequencies will cause up to 30 dB spatial variations of the sound pressure level in the room. This will take place not only at...... resonance frequencies, but more or less at all frequencies. A time based room correction system named CABS (Controlled Acoustic Bass System) has been developed and is able to create a homogeneous sound field in the whole room at low frequencies by proper placement of multiple loudspeakers. A normal setup...

  14. Room temperature synthesis of Ni-based alloy nanoparticles by radiolysis.

    Energy Technology Data Exchange (ETDEWEB)

    Nenoff, Tina Maria; Berry, Donald T.; Lu, Ping; Leung, Kevin; Provencio, Paula Polyak; Stumpf, Roland Rudolph; Huang, Jian Yu; Zhang, Zhenyuan

    2009-09-01

    Room temperature radiolysis, density functional theory, and various nanoscale characterization methods were used to synthesize and fully describe Ni-based alloy nanoparticles (NPs) that were synthesized at room temperature. These complementary methods provide a strong basis in understanding and describing metastable phase regimes of alloy NPs whose reaction formation is determined by kinetic rather than thermodynamic reaction processes. Four series of NPs, (Ag-Ni, Pd-Ni, Co-Ni, and W-Ni) were analyzed and characterized by a variety of methods, including UV-vis, TEM/HRTEM, HAADF-STEM and EFTEM mapping. In the first focus of research, AgNi and PdNi were studied. Different ratios of Ag{sub x}- Ni{sub 1-x} alloy NPs and Pd{sub 0.5}- Ni{sub 0.5} alloy NP were prepared using a high dose rate from gamma irradiation. Images from high-angle annular dark-field (HAADF) show that the Ag-Ni NPs are not core-shell structure but are homogeneous alloys in composition. Energy filtered transmission electron microscopy (EFTEM) maps show the homogeneity of the metals in each alloy NP. Of particular interest are the normally immiscible Ag-Ni NPs. All evidence confirmed that homogeneous Ag-Ni and Pd-Ni alloy NPs presented here were successfully synthesized by high dose rate radiolytic methodology. A mechanism is provided to explain the homogeneous formation of the alloy NPs. Furthermore, studies of Pd-Ni NPs by in situ TEM (with heated stage) shows the ability to sinter these NPs at temperatures below 800 C. In the second set of work, CoNi and WNi superalloy NPs were attempted at 50/50 concentration ratios using high dose rates from gamma irradiation. Preliminary results on synthesis and characterization have been completed and are presented. As with the earlier alloy NPs, no evidence of core-shell NP formation occurs. Microscopy results seem to indicate alloying occurred with the CoNi alloys. However, there appears to be incomplete reduction of the Na{sub 2}WO{sub 4} to form the W

  15. Room-temperature magnetic properties of SiC based nanowires synthesized via microwave heating method

    Science.gov (United States)

    Liu, Song; Wang, Jigang

    2016-07-01

    Two kinds of ferromagnetic SiC based nanowires with and without Ni catalyst were successfully synthesized by employing microwave heating method. The comprehensive characterizations and vibrating sample magnetometer (VSM) have been applied to investigate the micro-structures and magnetic properties of as-grown nanowires. For the nanowires synthesized without using Ni catalyst, the diameters and lengths are in the range of 20-60 nm and dozens of micrometers, respectively. Particularly, the results of transmission electron microscopy (TEM) show that the nanowires consist of SiC core and SiOx shell. The SiC/SiOx coaxial nanowires exhibit room-temperature ferromagnetism with saturation magnetization (Ms) of 0.2 emu/g. As to the nanowires obtained using Ni catalyst, the scanning electron microscopy (SEM) results indicate that the Ni catalyzed nanowires have a nano-particle attached on the tip and a uniform diameter of approximately 50 nm. The vapor-liquid-solid (VLS) growth mechanism can be used to explain the formation of the Ni catalyzed nanowires. The detection result of VSM indicates that the Ni catalyzed nanowires possess the paramagnetism and the ferromagnetism, simultaneously. The enhancement of the ferromagnetism, compared with the SiC/SiOx coaxial nanowires, could be attributed to the Ni2Si and NiSi phases.

  16. Prediction of silicon-based room temperature quantum spin Hall insulator via orbital mixing

    Science.gov (United States)

    Fu, Huixia; Ren, Jun; Chen, Lan; Si, Chen; Qiu, Jinglan; Li, Wenbin; Zhang, Jin; Sun, Jiatao; Li, Hui; Wu, Kehui; Duan, Wenhui; Meng, Sheng

    2016-03-01

    The search for realistic materials capable of supporting the room temperature quantum spin Hall (QSH) effect remains a challenge, especially when compatibility with the current electronics industry is required. We report a theoretical prediction to identify halogenated silicon films as excellent candidates, which demonstrate high stability, flexibility, and tunable spin-orbit coupling (SOC) gaps up to ∼0.5 eV under minimal strain below 3%. The extraordinary SOC strength is mainly contributed by the p-orbital of heavy halogen atoms hybridized with the p x,y -orbitals of Si scaffold, and thus can be easily manipulated by strain (being ∼100 times more effective than in silicene) or substrate. Not only the instability problem of silicene for real applications is solved, but also it provides a new strategy to drastically enhance SOC of light-element scaffolds by orbital hybridization. The silicon-based QSH insulator is most promising for developing next-generation, low-power consumption nanoelectronics and spintronics at ambient conditions.

  17. [Correction method for infrared spectral emissivity measurement system based on integrating sphere reflectometer].

    Science.gov (United States)

    Zhang, Yu-Feng; Dai, Jing-Min; Zhang, Yu; Pan, Wei-Dong; Zhang, Lei

    2013-08-01

    In view of the influence of non-ideal reference standard on spectral emissivity measurement, by analyzing the principle of infrared emissivity measurement system based on integrating sphere reflectometer, a calibration method suitable for measuring spectral emissivity system using the reflection measurement was proposed. By fitting a spectral reflectance curve of the reference standard sample to the given reflectance data, the correction coefficient of measurement system was computed. Then the output voltage curve of reference standard sample was corrected by this coefficient. The system error caused by the imperfection of reference standard was eliminated. The correction method was applied to the spectral emissivity measurement system based on integrating sphere reflectometer. The results measured by the corrected system and the results measured by energy comparison measurement were compared to verify the feasibility and effectivity of this correction method in improving the accuracy of spectral emissivity measurement.

  18. [Correction method for infrared spectral emissivity measurement system based on integrating sphere reflectometer].

    Science.gov (United States)

    Zhang, Yu-Feng; Dai, Jing-Min; Zhang, Yu; Pan, Wei-Dong; Zhang, Lei

    2013-08-01

    In view of the influence of non-ideal reference standard on spectral emissivity measurement, by analyzing the principle of infrared emissivity measurement system based on integrating sphere reflectometer, a calibration method suitable for measuring spectral emissivity system using the reflection measurement was proposed. By fitting a spectral reflectance curve of the reference standard sample to the given reflectance data, the correction coefficient of measurement system was computed. Then the output voltage curve of reference standard sample was corrected by this coefficient. The system error caused by the imperfection of reference standard was eliminated. The correction method was applied to the spectral emissivity measurement system based on integrating sphere reflectometer. The results measured by the corrected system and the results measured by energy comparison measurement were compared to verify the feasibility and effectivity of this correction method in improving the accuracy of spectral emissivity measurement. PMID:24159891

  19. Design and modernization of control rooms according to new I and C systems based on HFE principles

    Energy Technology Data Exchange (ETDEWEB)

    Rejas, Luis; Larraz, Javier, E-mail: lrejas@tecnatom.e, E-mail: jlarraz@tecnatom.e [Tecnatom S.A., San Sebastian de los Reyes, Madrid (Spain). New Control Room Design Dept.; Ortega, Fernando, E-mail: fortega@tecnatom.e [Tecnatom S.A., San Sebastian de los Reyes, Madrid (Spain). Control Room and Simulation Dept.

    2011-07-01

    The use of new digital I and C systems in the design of new nuclear power plants, as well as the modernization of existing facilities, implies relevant changes in the control room design. New I and C systems provide new features that affect the control room operating concept. Therefore, a detailed analysis is required to take into consideration all the operating and human factors aspects. Based on Tecnatom experience in the field, this article presents the methodological approach used as well as the most relevant aspects of this kind of project. (author)

  20. GLAS/ICESat L1B Global Waveform-based Range Corrections Data V033

    Data.gov (United States)

    National Aeronautics and Space Administration — The level 1B waveform parameterization data will contain waveform-based range corrections and surface characteristics at the full 40 per second resolution. Data...

  1. Active low frequency sound field control in a listening room using CABS (Controlled Acoustic Bass System) will also reduce the sound transmitted to neighbour rooms

    DEFF Research Database (Denmark)

    Nielsen, Sofus Birkedal; Celestinos, Adrian

    2012-01-01

    is possible at modal frequencies. For that reason the modal frequencies in the source room will also have big impact on the transmission to neighbour rooms. These low frequency resonance frequencies are very audible in the source room but also in neighbour rooms as a booming bass. CABS (Controlled Acoustic...... Bass System) is a time based room correction system for reproduced sound using loudspeakers. The system can remove room modes at low frequencies, by active cancelling the reflection from at the rear wall to a normal stereo setup. Measurements in a source room using CABS and in two neighbour rooms have...... shown a reduction in sound transmission of up to 10 dB at resonance frequencies and a reduction at broadband noise of 3 – 5 dB at frequencies up to 100 Hz. The ideas and understanding of the CABS system will also be given....

  2. Virtual Seminar Room

    DEFF Research Database (Denmark)

    Forchhammer, Søren Otto; Fosgerau, Anders; Hansen, Peter Søren Kirk;

    1999-01-01

    The initial design considerations and research goals for an ATM network based virtual seminar room with 5 sites are presented.......The initial design considerations and research goals for an ATM network based virtual seminar room with 5 sites are presented....

  3. Room Acoustics

    Science.gov (United States)

    Kuttruff, Heinrich; Mommertz, Eckard

    The traditional task of room acoustics is to create or formulate conditions which ensure the best possible propagation of sound in a room from a sound source to a listener. Thus, objects of room acoustics are in particular assembly halls of all kinds, such as auditoria and lecture halls, conference rooms, theaters, concert halls or churches. Already at this point, it has to be pointed out that these conditions essentially depend on the question if speech or music should be transmitted; in the first case, the criterion for transmission quality is good speech intelligibility, in the other case, however, the success of room-acoustical efforts depends on other factors that cannot be quantified that easily, not least it also depends on the hearing habits of the listeners. In any case, absolutely "good acoustics" of a room do not exist.

  4. Room temperature phosphorimetric determination of bromate in flour based on energy transfer.

    Science.gov (United States)

    Menendez-Miranda, Mario; Fernandez-Argüelles, Maria T; Costa-Fernandez, Jose M; Pereiro, Rosario; Sanz-Medel, Alfredo

    2013-11-15

    Determination of bromate ions in contaminated flour samples by using a room temperature phosphorescence (RTP) optosensor is described. The optosensor is based on the non-radiative energy transfer from α-bromonaphthalene (a phosphorescent molecule insensitive to the presence of the analyte) acting as donor, to an energy acceptor bromate-sensitive molecule (trifluoperazine hydrochloride). The RTP emission of the selected donor greatly overlaps with the absorption spectrum of the acceptor, resulting in a decrease of the measured signal as the concentration of bromate ions increases. A simple and general procedure is proposed to carry out the incorporation of both the donor and acceptor molecules in an appropriate solid material (sensing phase) through the co-immobilization of the species in a sol-gel inorganic matrix. The optimum amounts of the sol-gel precursors, including silica precursors, type of catalysis, and concentrations of donor and acceptor molecules, have been evaluated in order to obtain the best analytical features of the proposed optosensor for bromate determination. The highly stable developed sensing phase shows a selective and reversible response towards bromate even in presence of dissolved oxygen (a well-known quencher of the RTP). The calibration graphs were linear up to 200 mg L(-1), with a detection limit for bromate dissolved in aqueous medium of 0.2 mg L(-1). Sample throughput of the proposed optosensor was about 18 measurements h(-1). Application of the developed sensing phase was successfully proved for the detection of bromate ions in commercial flours, obtaining good recoveries. PMID:24148398

  5. A novel NO2 gas sensor based on Hall effect operating at room temperature

    Science.gov (United States)

    Lin, J. Y.; Xie, W. M.; He, X. L.; Wang, H. C.

    2016-09-01

    Tungsten trioxide nanoparticles were obtained by a simple thermal oxidation approach. The structural and morphological properties of these nanoparticles are investigated using XRD, SEM and TEM. A WO3 thick film was deposited on the four Au electrodes to be a WO3 Hall effect sensor. The sensor was tested between magnetic field in a plastic test chamber. Room-temperature nitrogen dioxide sensing characteristics of Hall effect sensor were studied for various concentration levels of nitrogen dioxide at dry air and humidity conditions. A typical room-temperature response of 3.27 was achieved at 40 ppm of NO2 with a response and recovery times of 36 and 45 s, respectively. NO2 gas sensing mechanism of Hall effect sensor was also studied. The room-temperature operation, with the low deposition cost of the sensor, suggests suitability for developing a low-power cost-effective nitrogen dioxide sensor.

  6. Choosing the correct radiologic test. Case-based teaching files

    International Nuclear Information System (INIS)

    Presents a stimulating guide to the appropriate choice of radiologic exam in more than 400 clinical scenarios in all medical subspecialties. Based on the American College of Radiology's Appropriateness Criteria. Features an interactive quiz format. Includes correlative images of pathologies illustrating the diagnostic power of the best exam in each scenario. Serves as an ideal tool for self-study and evaluation of students' knowledge. With the rapid growth in the cost of imaging and political and market pressures to contain health care costs, physicians are being encouraged to order only appropriate radiologic exams and to rationalize their choices. The American College of Radiology (ACR) Appropriateness Criteria have emerged as a widely accepted standard by which the appropriate use of radiologic exams is judged. This book is designed to enable physicians and trainees to learn the ACR recommendations in a clinically relevant and intellectually stimulating way. More than 400 clinical scenarios are organized into ten modules based on organ systems. Each scenario is addressed by means of an interactive quiz in which the reader is invited to select the best option from a number of imaging modalities. Each choice is given a numerical rating of appropriateness, with accompanying comments when necessary. Correlative images of pathologies are included to enhance the reader's appreciation of the diagnostic power of the modality in question. This book is ideal as a tool both for self-study and for quantitative evaluation of students' knowledge.

  7. Choosing the correct radiologic test. Case-based teaching files

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Susanna I.; Thrall, James H. [Harvard Medical School, Boston, MA (United States). Dept. of Radiology

    2013-07-01

    Presents a stimulating guide to the appropriate choice of radiologic exam in more than 400 clinical scenarios in all medical subspecialties. Based on the American College of Radiology's Appropriateness Criteria. Features an interactive quiz format. Includes correlative images of pathologies illustrating the diagnostic power of the best exam in each scenario. Serves as an ideal tool for self-study and evaluation of students' knowledge. With the rapid growth in the cost of imaging and political and market pressures to contain health care costs, physicians are being encouraged to order only appropriate radiologic exams and to rationalize their choices. The American College of Radiology (ACR) Appropriateness Criteria have emerged as a widely accepted standard by which the appropriate use of radiologic exams is judged. This book is designed to enable physicians and trainees to learn the ACR recommendations in a clinically relevant and intellectually stimulating way. More than 400 clinical scenarios are organized into ten modules based on organ systems. Each scenario is addressed by means of an interactive quiz in which the reader is invited to select the best option from a number of imaging modalities. Each choice is given a numerical rating of appropriateness, with accompanying comments when necessary. Correlative images of pathologies are included to enhance the reader's appreciation of the diagnostic power of the modality in question. This book is ideal as a tool both for self-study and for quantitative evaluation of students' knowledge.

  8. Room-temperature fabrication of light-emitting thin films based on amorphous oxide semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Junghwan, E-mail: JH.KIM@lucid.msl.titech.ac.jp; Miyokawa, Norihiko; Ide, Keisuke [Materials and Structures Laboratory, Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama (Japan); Toda, Yoshitake [Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox SE-6, 4259 Nagatsuta, Midori-ku, Yokohama (Japan); Hiramatsu, Hidenori; Hosono, Hideo; Kamiya, Toshio [Materials and Structures Laboratory, Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama (Japan); Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox SE-6, 4259 Nagatsuta, Midori-ku, Yokohama (Japan)

    2016-01-15

    We propose a light-emitting thin film using an amorphous oxide semiconductor (AOS) because AOS has low defect density even fabricated at room temperature. Eu-doped amorphous In-Ga-Zn-O thin films fabricated at room temperature emitted intense red emission at 614 nm. It is achieved by precise control of oxygen pressure so as to suppress oxygen-deficiency/excess-related defects and free carriers. An electronic structure model is proposed, suggesting that non-radiative process is enhanced mainly by defects near the excited states. AOS would be a promising host for a thin film phosphor applicable to flexible displays as well as to light-emitting transistors.

  9. On isocentre adjustment and quality control in linear accelerator based radiosurgery with circular collimators and room lasers

    Science.gov (United States)

    Treuer, H.; Hoevels, M.; Luyken, K.; Gierich, A.; Kocher, M.; Müller, R.-P.; Sturm, V.

    2000-08-01

    We have developed a densitometric method for measuring the isocentric accuracy and the accuracy of marking the isocentre position for linear accelerator based radiosurgery with circular collimators and room lasers. Isocentric shots are used to determine the accuracy of marking the isocentre position with room lasers and star shots are used to determine the wobble of the gantry and table rotation movement, the effect of gantry sag, the stereotactic collimator alignment, and the minimal distance between gantry and table rotation axes. Since the method is based on densitometric measurements, beam spot stability is implicitly tested. The method developed is also suitable for quality assurance and has proved to be useful in optimizing isocentric accuracy. The method is simple to perform and only requires a film box and film scanner for instrumentation. Thus, the method has the potential to become widely available and may therefore be useful in standardizing the description of linear accelerator based radiosurgical systems.

  10. Pixel-Based CTI Corrections for HST/STIS CCD Data

    Science.gov (United States)

    Biretta, John A.; Lockwood, Sean A.; Debes, John H.

    2016-01-01

    The Space Telescope Imaging Spectrograph (STIS) team at STScI has created stand-alone automated software to apply Charge Transfer Inefficiency (CTI) corrections to STIS CCD data. CTI results from radiation damage to the CCD detector during its many years in the space environment on-board the Hubble Space Telescope (HST). The software will remove trails and other image artifacts caused by CTI, and will help correct target fluxes and positions to their proper values. The software script (stis_cti v1.0) uses a pixel-based correction algorithm, and will correct both images and spectra. It automatically generates CTI corrected dark reference files, applies CTI corrections to the science data, and outputs the usual CALSTIS products with CTI corrections applied. Currently only the most common observation modes are supported -- full-frame, non-binned data, taken with the default CCD amplifier; future enhancements may include sub-array data. It is available free to the community for download and use. Further information can be found at www.stsci.edu/hst/stis/software/analyzing/scripts/pixel_based_CTI.

  11. Automated motion correction based on target tracking for dynamic nuclear medicine studies

    Science.gov (United States)

    Cao, Xinhua; Tetrault, Tracy; Fahey, Fred; Treves, Ted

    2008-03-01

    Nuclear medicine dynamic studies of kidneys, bladder and stomach are important diagnostic tools. Accurate generation of time-activity curves from regions of interest (ROIs) requires that the patient remains motionless for the duration of the study. This is not always possible since some dynamic studies may last from several minutes to one hour. Several motion correction solutions have been explored. Motion correction using external point sources is inconvenient and not accurate especially when motion results from breathing, organ motion or feeding rather than from body motion alone. Centroid-based motion correction assumes that activity distribution is only inside the single organ (without background) and uniform, but this approach is impractical in most clinical studies. In this paper, we present a novel technique of motion correction that first tracks the organ of interest in a dynamic series then aligns the organ. The implementation algorithm for target tracking-based motion correction consists of image preprocessing, target detection, target positioning, motion estimation and prediction, tracking (new search region generation) and target alignment. The targeted organ is tracked from the first frame to the last one in the dynamic series to generate a moving trajectory of the organ. Motion correction is implemented by aligning the organ ROIs in the image series to the location of the organ in the first image. The proposed method of motion correction has been applied to several dynamic nuclear medicine studies including radionuclide cystography, dynamic renal scintigraphy, diuretic renography and gastric emptying scintigraphy.

  12. Correcting for catchment area nonresidency in studies based on tumor-registry data

    International Nuclear Information System (INIS)

    We discuss the effect of catchment area nonresidency on estimates of cancer incidence from a tumor-registry-based cohort study and demonstrate that a relatively simple correction is possible in the context of Poisson regression analysis if individual residency histories or the probabilities of residency are known. A comparison of a complete data maximum likelihood analysis with several Poisson regression analyses demonstrates the adequacy of the simple correction in a large simulated data set. We compare analyses of stomach-cancer incidence from the Radiation Effects Research Foundation tumor registry with and without the correction. We also discuss some implications of including cases identified only on the basis of death certificates. (author)

  13. Simulation-driven design by knowledge-based response correction techniques

    CERN Document Server

    Koziel, Slawomir

    2016-01-01

    Focused on efficient simulation-driven multi-fidelity optimization techniques, this monograph on simulation-driven optimization covers simulations utilizing physics-based low-fidelity models, often based on coarse-discretization simulations or other types of simplified physics representations, such as analytical models. The methods presented in the book exploit as much as possible any knowledge about the system or device of interest embedded in the low-fidelity model with the purpose of reducing the computational overhead of the design process. Most of the techniques described in the book are of response correction type and can be split into parametric (usually based on analytical formulas) and non-parametric, i.e., not based on analytical formulas. The latter, while more complex in implementation, tend to be more efficient. The book presents a general formulation of response correction techniques as well as a number of specific methods, including those based on correcting the low-fidelity model response (out...

  14. Development of CBCT-based prostate setup correction strategies and impact of rectal distension

    OpenAIRE

    Boydev, Christine; Taleb-Ahmed, Abdelmalik; Derraz, Foued; Peyrodie, Laurent; Thiran, Jean-Philippe; Pasquier, David

    2015-01-01

    Background Cone-beam computed tomography (CBCT) image-guided radiotherapy (IGRT) systems are widely used tools to verify and correct the target position before each fraction, allowing to maximize treatment accuracy and precision. In this study, we evaluate automatic three-dimensional intensity-based rigid registration (RR) methods for prostate setup correction using CBCT scans and study the impact of rectal distension on registration quality. Methods We retrospectively analyzed 115 CBCT scans...

  15. Atmospheric correction of remote sensing imagery based on the surface spectrum's vector space

    Institute of Scientific and Technical Information of China (English)

    CHEN Chun; LIU ChengYu; ZHANG ShuQing

    2012-01-01

    Due to the atmosphere effect,the qualities of images decrease conspicuously,practically in the visible bands,in the processing of earth observation by the satellite-borne sensors.Thus,removing the atmosphere effects has become a key step to improve the qualities of images and to retrieve the actual reflectivity of surface features.An atmospheric correction approach,called ACVSS (Atmospheric Correction based Vector Space of Spectrum),is proposed here based on the vector space of the features'spectrum.The reflectance image of each band is retrieved first according to the radiative transfer equation,then the spectrum's vector space is constructed using the infrared bands,and finally the residual errors of the reflectance images in the visible bands are corrected based on the pixel position in the spectrum's vector space.The proposed methodology is verified through atmospheric correction on Landsat-7 ETM+ imagery.The experimental results show that our method is more accurate and the corrected image is more distinct,compared with those offered by current popular atmospheric correction software.

  16. Operator’s cognitive, communicative and operative activities based workload measurement of advanced main control room

    International Nuclear Information System (INIS)

    Highlights: • An advanced MMIS in the advanced MCR requires new roles and tasks of operators. • A new workload evaluation framework is needed for a new MMIS environment. • This work suggests a new workload measurement approach (COCOA) for an advanced MCR. • COCOA enables 3-dimensional measurement of cognition, communication and operation. • COCOA workload evaluation of the reference plant through simulation was performed. - Abstract: An advanced man–machine interface system (MMIS) with a computer-based procedure system and high-tech control/alarm system is installed in the advanced main control room (MCR) of a nuclear power plant. Accordingly, though the task of the operators has been changed a great deal, owing to a lack of appropriate guidelines on the role allocation or communication method of the operators, operators should follow the operating strategies of conventional MCR and the problem of an unbalanced workload for each operator can be raised. Thus, it is necessary to enhance the operation capability and improve the plant safety by developing guidelines on the role definition and communication of operators in an advanced MCR. To resolve this problem, however, a method for measuring the workload according to the work execution of the operators is needed, but an applicable method is not available. In this research, we propose a COgnitive, Communicative and Operational Activities measurement approach (COCOA) to measure and evaluate the workload of operators in an advanced MCR. This paper presents the taxonomy for additional operation activities of the operators to use the computerized procedures and soft control added to an advanced MCR, which enables an integrated measurement of the operator workload in various dimensions of cognition, communication, and operation. To check the applicability of COCOA, we evaluated the operator workload of an advanced MCR of a reference power plant through simulation training experiments. As a result, the amount

  17. Design of a beam shaping assembly and preliminary modelling of a treatment room for accelerator-based BNCT at CNEA

    International Nuclear Information System (INIS)

    This work reports on the characterisation of a neutron beam shaping assembly (BSA) prototype and on the preliminary modelling of a treatment room for BNCT within the framework of a research programme for the development and construction of an accelerator-based BNCT irradiation facility in Buenos Aires, Argentina. The BSA prototype constructed has been characterised by means of MCNP simulations as well as a set of experimental measurements performed at the Tandar accelerator at the National Atomic Energy Commission of Argentina. - Highlights: ► Characterisation of a neutron beam shaping assembly for accelerator-based BNCT. ► Measurements: total and epi-cadmium neutron fluxes and beam homogeneity. ► Calculations: Monte Carlo simulations with the MCNP code. ► Measured and calculated figure-of-merit parameters in agreement with those of IAEA. ► Initial MCNP dose calculations for a treatment room to define future design actions.

  18. Event-based knowledge elicitation of operating room management decision-making using scenarios adapted from information systems data

    OpenAIRE

    Epstein Richard H; Wachtel Ruth E; Dexter Franklin

    2011-01-01

    Abstract Background No systematic process has previously been described for a needs assessment that identifies the operating room (OR) management decisions made by the anesthesiologists and nurse managers at a facility that do not maximize the efficiency of use of OR time. We evaluated whether event-based knowledge elicitation can be used practically for rapid assessment of OR management decision-making at facilities, whether scenarios can be adapted automatically from information systems dat...

  19. Solution processed CuPc based nanowires for room temperature Cl2 gas sensing applications

    Science.gov (United States)

    Saini, Rajan; Mahajan, Aman; Bedi, R. K.; Aswal, D. K.

    2013-06-01

    Self assembled nanowires (NWs) of Cu (II) 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-Phthalocyanine (CuPcOC4) molecule have been grown on glass substrate by solvent vapours annealing approach. The density and dimensions of NWs is found to be dependent on the concentration of solution and time of exposure. The possible formation mechanism of these structures is π-π interaction between phthalocyanine molecules. The improved conductivity of these NWs can be due to 1D co-facial arrangement of molecules in NWs. Nws are found to be selective for Cl2 gas at room temperature. The room temperature Cl2 sensing characteristics of NWs have been discussed in this paper.

  20. Room-temperature fabrication of light-emitting thin films based on amorphous oxide semiconductor

    Directory of Open Access Journals (Sweden)

    Junghwan Kim

    2016-01-01

    Full Text Available We propose a light-emitting thin film using an amorphous oxide semiconductor (AOS because AOS has low defect density even fabricated at room temperature. Eu-doped amorphous In-Ga-Zn-O thin films fabricated at room temperature emitted intense red emission at 614 nm. It is achieved by precise control of oxygen pressure so as to suppress oxygen-deficiency/excess-related defects and free carriers. An electronic structure model is proposed, suggesting that non-radiative process is enhanced mainly by defects near the excited states. AOS would be a promising host for a thin film phosphor applicable to flexible displays as well as to light-emitting transistors.

  1. Correction of distribution density of deep sea manganese nodules based on their occurrence type

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jung-Seock; Kong, Gee-Soo [Korea Institute of Geoscience and Mineral Resources, Taejeon(Korea)

    2001-06-01

    This study aims to improve the method for more exact estimation of the distribution density and amount of seabed manganese modules in the Korean districts of northeastern Pacific, which are registered at International Seabed Authority(ISA). As the result of the study, correction formulas are obtained, and the grade of correction shows great differences depending upon the type of nodule occurrence. Four types of nodule occurrence are recognized based on the combination of shape, size and distribution density. The abundance of nodules are calculated from the area ratios of grabbing nodules and the correlation modules of sample abundances, and finally are obtained the correction formulas multiplying the corrective coefficients (experimental values between the recoveries and the covered ratios) to the bottom abundances. (author). 7 refs., 6 tabs., 6 figs.

  2. Implementation and Application of PSF-Based EPI Distortion Correction to High Field Animal Imaging

    Directory of Open Access Journals (Sweden)

    Dominik Paul

    2009-01-01

    Full Text Available The purpose of this work is to demonstrate the functionality and performance of a PSF-based geometric distortion correction for high-field functional animal EPI. The EPI method was extended to measure the PSF and a postprocessing chain was implemented in Matlab for offline distortion correction. The correction procedure was applied to phantom and in vivo imaging of mice and rats at 9.4T using different SE-EPI and DWI-EPI protocols. Results show the significant improvement in image quality for single- and multishot EPI. Using a reduced FOV in the PSF encoding direction clearly reduced the acquisition time for PSF data by an acceleration factor of 2 or 4, without affecting the correction quality.

  3. Monte Carlo-based Noise Compensation in Coil Intensity Corrected Endorectal MRI

    CERN Document Server

    Lui, Dorothy; Haider, Masoom; Wong, Alexander

    2015-01-01

    Background: Prostate cancer is one of the most common forms of cancer found in males making early diagnosis important. Magnetic resonance imaging (MRI) has been useful in visualizing and localizing tumor candidates and with the use of endorectal coils (ERC), the signal-to-noise ratio (SNR) can be improved. The coils introduce intensity inhomogeneities and the surface coil intensity correction built into MRI scanners is used to reduce these inhomogeneities. However, the correction typically performed at the MRI scanner level leads to noise amplification and noise level variations. Methods: In this study, we introduce a new Monte Carlo-based noise compensation approach for coil intensity corrected endorectal MRI which allows for effective noise compensation and preservation of details within the prostate. The approach accounts for the ERC SNR profile via a spatially-adaptive noise model for correcting non-stationary noise variations. Such a method is useful particularly for improving the image quality of coil i...

  4. A new approach for beam hardening correction based on the local spectrum distributions

    Energy Technology Data Exchange (ETDEWEB)

    Rasoulpour, Naser; Kamali-Asl, Alireza, E-mail: a_kamali@sbu.ac.ir; Hemmati, Hamidreza

    2015-09-11

    Energy dependence of material absorption and polychromatic nature of x-ray beams in the Computed Tomography (CT) causes a phenomenon which called “beam hardening”. The purpose of this study is to provide a novel approach for Beam Hardening (BH) correction. This approach is based on the linear attenuation coefficients of Local Spectrum Distributions (LSDs) in the various depths of a phantom. The proposed method includes two steps. Firstly, the hardened spectra in various depths of the phantom (or LSDs) are estimated based on the Expectation Maximization (EM) algorithm for arbitrary thickness interval of known materials in the phantom. The performance of LSD estimation technique is evaluated by applying random Gaussian noise to transmission data. Then, the linear attenuation coefficients with regarding to the mean energy of LSDs are obtained. Secondly, a correction function based on the calculated attenuation coefficients is derived in order to correct polychromatic raw data. Since a correction function has been used for the conversion of the polychromatic data to the monochromatic data, the effect of BH in proposed reconstruction must be reduced in comparison with polychromatic reconstruction. The proposed approach has been assessed in the phantoms which involve less than two materials, but the correction function has been extended for using in the constructed phantoms with more than two materials. The relative mean energy difference in the LSDs estimations based on the noise-free transmission data was less than 1.5%. Also, it shows an acceptable value when a random Gaussian noise is applied to the transmission data. The amount of cupping artifact in the proposed reconstruction method has been effectively reduced and proposed reconstruction profile is uniform more than polychromatic reconstruction profile. - Highlights: • A novel Beam Hardening (BH) correction approach was described. • A new concept named Local Spectrum Distributions (LSDs) was used to BH

  5. A new approach for beam hardening correction based on the local spectrum distributions

    International Nuclear Information System (INIS)

    Energy dependence of material absorption and polychromatic nature of x-ray beams in the Computed Tomography (CT) causes a phenomenon which called “beam hardening”. The purpose of this study is to provide a novel approach for Beam Hardening (BH) correction. This approach is based on the linear attenuation coefficients of Local Spectrum Distributions (LSDs) in the various depths of a phantom. The proposed method includes two steps. Firstly, the hardened spectra in various depths of the phantom (or LSDs) are estimated based on the Expectation Maximization (EM) algorithm for arbitrary thickness interval of known materials in the phantom. The performance of LSD estimation technique is evaluated by applying random Gaussian noise to transmission data. Then, the linear attenuation coefficients with regarding to the mean energy of LSDs are obtained. Secondly, a correction function based on the calculated attenuation coefficients is derived in order to correct polychromatic raw data. Since a correction function has been used for the conversion of the polychromatic data to the monochromatic data, the effect of BH in proposed reconstruction must be reduced in comparison with polychromatic reconstruction. The proposed approach has been assessed in the phantoms which involve less than two materials, but the correction function has been extended for using in the constructed phantoms with more than two materials. The relative mean energy difference in the LSDs estimations based on the noise-free transmission data was less than 1.5%. Also, it shows an acceptable value when a random Gaussian noise is applied to the transmission data. The amount of cupping artifact in the proposed reconstruction method has been effectively reduced and proposed reconstruction profile is uniform more than polychromatic reconstruction profile. - Highlights: • A novel Beam Hardening (BH) correction approach was described. • A new concept named Local Spectrum Distributions (LSDs) was used to BH

  6. Evaluation of Bias Correction Method for Satellite-Based Rainfall Data

    Directory of Open Access Journals (Sweden)

    Haris Akram Bhatti

    2016-06-01

    Full Text Available With the advances in remote sensing technology, satellite-based rainfall estimates are gaining attraction in the field of hydrology, particularly in rainfall-runoff modeling. Since estimates are affected by errors correction is required. In this study, we tested the high resolution National Oceanic and Atmospheric Administration’s (NOAA Climate Prediction Centre (CPC morphing technique (CMORPH satellite rainfall product (CMORPH in the Gilgel Abbey catchment, Ethiopia. CMORPH data at 8 km-30 min resolution is aggregated to daily to match in-situ observations for the period 2003–2010. Study objectives are to assess bias of the satellite estimates, to identify optimum window size for application of bias correction and to test effectiveness of bias correction. Bias correction factors are calculated for moving window (MW sizes and for sequential windows (SW’s of 3, 5, 7, 9, …, 31 days with the aim to assess error distribution between the in-situ observations and CMORPH estimates. We tested forward, central and backward window (FW, CW and BW schemes to assess the effect of time integration on accumulated rainfall. Accuracy of cumulative rainfall depth is assessed by Root Mean Squared Error (RMSE. To systematically correct all CMORPH estimates, station based bias factors are spatially interpolated to yield a bias factor map. Reliability of interpolation is assessed by cross validation. The uncorrected CMORPH rainfall images are multiplied by the interpolated bias map to result in bias corrected CMORPH estimates. Findings are evaluated by RMSE, correlation coefficient (r and standard deviation (SD. Results showed existence of bias in the CMORPH rainfall. It is found that the 7 days SW approach performs best for bias correction of CMORPH rainfall. The outcome of this study showed the efficiency of our bias correction approach.

  7. Evaluation of in vitro antibacterial effect of room curing polymethylmethacrylate material adding nano-silver base inorganic antibacterial agents

    International Nuclear Information System (INIS)

    Objective: To investigate the antibacterial effect of room curing polymethylmethacrylate (PMMA) material adding nano-silver base inorganic antibacterial agent and to detect the changes of its mechanical property. Methods: Nano-silver base inorganic antibacterial agent was added to the room curing PMMA material in the range of 0.5% -3.0% at an interval of 0.5% by ball milling specimen. Antibacterial rates of the specimens were detected by film method. Bending strength, impact strength, and wear resistance of the specimens were respectively detected on electronic universal testing machine, impact test machine and friction and wear test machine. Results: The antibacterial rates of Streptococcus mutans and Candida albicans were more than 50% when antibiotics content was 1.0% . The antibacterial rates of Streptococcus mutans and Candida albicans were more than 90% when the antibiotics content was 2.5% . The three mechanical properties were increased compared with control group when the antibacterial agents were in the range of 1.0% -1.5% . Then the three mechanical properties were decreased with the increasing of antimicrobial concentration. When the antibiotics content was 2.0% , the wear resistance had significant difference compared with control group (P<0.05); when the antibiotics content was 2.5% , the bending strength and impact strength had significant difference compared with control group (P<0.05). Conclusion: The antibacterial effect of room curing PMMA adding nano-silver base inorganic antibacterial agent is ideal. The antibacterial rate is increased gradually with the increasing content of antibacterial agents. There is no significant effect on the mechanical properties of room curing PMMA material, but the antibacterial effects are satisfied when the content of antibacterial agents is 2.0% . (authors)

  8. Room Temperature Co-Precipitation Synthesis of Magnetite Nanoparticles in a Large pH Window with Different Bases

    Directory of Open Access Journals (Sweden)

    Maria Cristina Mascolo

    2013-11-01

    Full Text Available Magnetite nanoparticles (Fe3O4 represent the most promising materials in medical applications. To favor high-drug or enzyme loading on the nanoparticles, they are incorporated into mesoporous materials to form a hybrid support with the consequent reduction of magnetization saturation. The direct synthesis of mesoporous structures appears to be of interest. To this end, magnetite nanoparticles have been synthesized using a one pot co-precipitation reaction at room temperature in the presence of different bases, such as NaOH, KOH or (C2H54NOH. Magnetite shows characteristics of superparamagnetism at room temperature and a saturation magnetization (Ms value depending on both the crystal size and the degree of agglomeration of individual nanoparticles. Such agglomeration appears to be responsible for the formation of mesoporous structures, which are affected by the pH, the nature of alkali, the slow or fast addition of alkaline solution and the drying modality of synthesized powders.

  9. MRI-Based Computed Tomography Metal Artifact Correction Method for Improving Proton Range Calculation Accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Park, Peter C. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Schreibmann, Eduard; Roper, Justin; Elder, Eric; Crocker, Ian [Department of Radiation Oncology, Winship Cancer Institute of Emory University, Atlanta, Georgia (United States); Fox, Tim [Varian Medical Systems, Palo Alto, California (United States); Zhu, X. Ronald [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Dong, Lei [Scripps Proton Therapy Center, San Diego, California (United States); Dhabaan, Anees, E-mail: anees.dhabaan@emory.edu [Department of Radiation Oncology, Winship Cancer Institute of Emory University, Atlanta, Georgia (United States)

    2015-03-15

    Purpose: Computed tomography (CT) artifacts can severely degrade dose calculation accuracy in proton therapy. Prompted by the recently increased popularity of magnetic resonance imaging (MRI) in the radiation therapy clinic, we developed an MRI-based CT artifact correction method for improving the accuracy of proton range calculations. Methods and Materials: The proposed method replaces corrupted CT data by mapping CT Hounsfield units (HU number) from a nearby artifact-free slice, using a coregistered MRI. MRI and CT volumetric images were registered with use of 3-dimensional (3D) deformable image registration (DIR). The registration was fine-tuned on a slice-by-slice basis by using 2D DIR. Based on the intensity of paired MRI pixel values and HU from an artifact-free slice, we performed a comprehensive analysis to predict the correct HU for the corrupted region. For a proof-of-concept validation, metal artifacts were simulated on a reference data set. Proton range was calculated using reference, artifactual, and corrected images to quantify the reduction in proton range error. The correction method was applied to 4 unique clinical cases. Results: The correction method resulted in substantial artifact reduction, both quantitatively and qualitatively. On respective simulated brain and head and neck CT images, the mean error was reduced from 495 and 370 HU to 108 and 92 HU after correction. Correspondingly, the absolute mean proton range errors of 2.4 cm and 1.7 cm were reduced to less than 2 mm in both cases. Conclusions: Our MRI-based CT artifact correction method can improve CT image quality and proton range calculation accuracy for patients with severe CT artifacts.

  10. Temporal high-pass non-uniformity correction algorithm based on grayscale mapping and hardware implementation

    Science.gov (United States)

    Jin, Minglei; Jin, Weiqi; Li, Yiyang; Li, Shuo

    2015-08-01

    In this paper, we propose a novel scene-based non-uniformity correction algorithm for infrared image processing-temporal high-pass non-uniformity correction algorithm based on grayscale mapping (THP and GM). The main sources of non-uniformity are: (1) detector fabrication inaccuracies; (2) non-linearity and variations in the read-out electronics and (3) optical path effects. The non-uniformity will be reduced by non-uniformity correction (NUC) algorithms. The NUC algorithms are often divided into calibration-based non-uniformity correction (CBNUC) algorithms and scene-based non-uniformity correction (SBNUC) algorithms. As non-uniformity drifts temporally, CBNUC algorithms must be repeated by inserting a uniform radiation source which SBNUC algorithms do not need into the view, so the SBNUC algorithm becomes an essential part of infrared imaging system. The SBNUC algorithms' poor robustness often leads two defects: artifacts and over-correction, meanwhile due to complicated calculation process and large storage consumption, hardware implementation of the SBNUC algorithms is difficult, especially in Field Programmable Gate Array (FPGA) platform. The THP and GM algorithm proposed in this paper can eliminate the non-uniformity without causing defects. The hardware implementation of the algorithm only based on FPGA has two advantages: (1) low resources consumption, and (2) small hardware delay: less than 20 lines, it can be transplanted to a variety of infrared detectors equipped with FPGA image processing module, it can reduce the stripe non-uniformity and the ripple non-uniformity.

  11. Spectroscopic evidence for 5f bands at room temperature in uranium-based heavy fermions

    International Nuclear Information System (INIS)

    We present data on the alloy system UPd/sub 3-x/Pt/sub x/ and show that in the double hexagonal phase (x 2.4) as well, except that the low-binding energy feature is locked in at E/sub F/ and shows evidence of energy dispersion at room temperature/endash/consistent with well-defined bands. Conversely, we show that even in well-behaved narrow band systems (USn3 there is evidence for satellite formation. 44 refs., 8 figs

  12. Room temperature NO2 sensor based on highly ordered porphyrin nanotubes.

    Science.gov (United States)

    Song, Feifei; Ma, Pan; Chen, Changlong; Jia, Jingna; Wang, Yucheng; Zhu, Peihua

    2016-07-15

    Highly ordered nanotubes of 5, 10, 15, 20-tetrakis(4-aminophenyl)porphyrin zinc (ZnTAP) are fabricated by using nanoporous anodized aluminum oxide (AAO) membrane as the template. Electronic absorption spectra, fluorescence spectra, transmission electron microscope (TEM), scanning electronic microscopy (SEM), low-angle X-ray diffraction (XRD) techniques are adopted to characterize these nanotubes. The highly ordered nanotubes of ZnTAP show good conductivity and present an efficient gas sensor platform for the ultrasensitive detection of NO2 under room temperature. The proposed sensor shows high sensitivity, reproducibility and fast response/recovery behavior, and provides a promising avenue for improving the sensing performance. PMID:27100904

  13. Preparation and characterization of room-temperature ferromagnetism GaMnN based on ion implantation

    Institute of Scientific and Technical Information of China (English)

    WANG; Jiqing(王基庆); CHEN; Pingping; (陈平平); LI; Zhifeng; (李志锋); GUO; Xuguang; (郭旭光); H.; Makino; T.; Yao; CHEN; Hong; (陈弘); HUANG; Qi; (黄绮); ZHOU; Junming; (周均铭); LU; Wei; (陆卫)

    2003-01-01

    This paper reports the fabrication of GaMnN ferromagnetic semiconductor on GaN substrate by high-dose Mn ion implantation. Both the structural and optical properties for Mn+-implanted GaN material were studied by X-ray diffraction, Raman scattering and photoluminescence. The results reveal that the implanted manganese incorporates on Ga site and GaMnN ternary phase is formed in the substrate. The magnetic behavior has been characterized by superconducting quantum interference device. The material shows room-temperature ferromagnetism. The temperature-dependent magnetization indicates different mechanism for ferromagnetism in Mn+-implanted GaN.

  14. Research on electrocardiogram baseline wandering correction based on wavelet transform, QRS barycenter fitting, and regional method.

    Science.gov (United States)

    Song, Jinzhong; Yan, Hong; Li, Yanjun; Mu, Kaiyu

    2010-09-01

    Baseline wandering in electrocardiogram (ECG) is one of the biggest interferences in visualization and computerized detection of waveforms (especially ST-segment) based on threshold decision. A new method based on wavelet transform, QRS barycenter fitting and regional method was proposed in this paper. Firstly, wavelet transform as a coarse correction was used to remove the baseline wandering, whose frequency bands were non-overlapping with that of ST-segment. Secondly, QRS barycenter fitting was applied as a detailed correction. The third, the regional method was used to transfer baseline to zero. Finally, the method in this paper was proved to perform better than filtering and function fitting methods in baseline wandering correction after the long-term ST database (LTST) verification. In addition, the proposed method is simple and easy to carry out, and in current use. PMID:20882381

  15. Enhancement of NH3 Gas Sensitivity at Room Temperature by Carbon Nanotube-Based Sensor Coated with Co Nanoparticles

    Directory of Open Access Journals (Sweden)

    Lich Quang Nguyen

    2013-01-01

    Full Text Available Multi-walled carbon nanotube (MWCNT film has been fabricated onto Pt-patterned alumina substrates using the chemical vapor deposition method for NH3 gas sensing applications. The MWCNT-based sensor is sensitive to NH3 gas at room temperature. Nanoclusters of Co catalysts have been sputtered on the surface of the MWCNT film to enhance gas sensitivity with respect to unfunctionalized CNT films. The gas sensitivity of Co-functionalized MWCNT-based gas sensors is thus significantly improved. The sensor exhibits good repeatability and high selectivity towards NH3, compared with alcohol and LPG.

  16. Scatter correction method for cone-beam CT based on interlacing-slit scan

    Science.gov (United States)

    Huang, Kui-Dong; Zhang, Hua; Shi, Yi-Kai; Zhang, Liang; Xu, Zhe

    2014-09-01

    Cone-beam computed tomography (CBCT) has the notable features of high efficiency and high precision, and is widely used in areas such as medical imaging and industrial non-destructive testing. However, the presence of the ray scatter reduces the quality of CT images. By referencing the slit collimation approach, a scatter correction method for CBCT based on the interlacing-slit scan is proposed. Firstly, according to the characteristics of CBCT imaging, a scatter suppression plate with interlacing slits is designed and fabricated. Then the imaging of the scatter suppression plate is analyzed, and a scatter correction calculation method for CBCT based on the image fusion is proposed, which can splice out a complete set of scatter suppression projection images according to the interlacing-slit projection images of the left and the right imaging regions in the scatter suppression plate, and simultaneously complete the scatter correction within the flat panel detector (FPD). Finally, the overall process of scatter suppression and correction is provided. The experimental results show that this method can significantly improve the clarity of the slice images and achieve a good scatter correction.

  17. Shielding design of a treatment room for an accelerator-based epithermal neutron irradiation facility for BNCT

    International Nuclear Information System (INIS)

    Protecting the facility personnel and the general public from radiation exposure is a primary safety concern of an accelerator-based epithermal neutron irradiation facility. This work makes an attempt at answering the questions open-quotes How much?close quotes and open-quotes What kind?close quotes of shielding will meet the occupational limits of such a facility. Shielding effectiveness is compared for ordinary and barytes concretes in combination with and without borated polyethylene. A calculational model was developed of a treatment room, patient open-quotes scatterer,close quotes and the epithermal neutron beam. The Monte Carlo code, MCNP, was used to compute the total effective dose equivalent rates at specific points of interest outside of the treatment room. A conservative occupational effective dose rate limit of 0.01 mSv h-1 was the guideline for this study. Conservative Monte Carlo calculations show that constructing the treatment room walls with 1.5 m of ordinary concrete, 1.2 m of barytes concrete, 1.0 m of ordinary concrete preceded by 10 cm of 5% boron-polyethylene, or 0.8 m of barytes concrete preceded by 10 cm of 5% boron-polyethylene will adequately protect facility personnel. 20 refs., 8 figs., 2 tabs

  18. Elements of the employee selection process: interviewing operating room staff.

    Science.gov (United States)

    Coleman, J

    1996-07-01

    Selecting the right staff for employment in an operating room (OR) is critical to the success of any OR manager. Legal considerations limit the ability to gather certain information. However, by applying the correct skills and techniques, the manager can develop an information base that will lead to better decisions when selecting employees who can contribute to an efficiently run department.

  19. Use of sampling based correction for non-radioactivity X-ray energy calibration

    Institute of Scientific and Technical Information of China (English)

    CHENG Cheng; WEI Yong-Bo; JIANG Da-Zhen

    2005-01-01

    As the requirement of non-radioactivity measurement has increased in recent years, various energy calibration methods applied in portable X-ray fluorescence (XRF) spectrometers have been developed. In this paper, a sampling based correction energy calibration has been discussed. In this method both history information and current state of the instrument are considered and relative high precision and reliability can be obtained.

  20. A novel energy mapping approach for CT-based attenuation correction in PET

    NARCIS (Netherlands)

    Teimourian, B.; Ay, M. R.; Zafarghandi, M. Shamsaie; Ghafarian, P.; Ghadiri, H.; Zaidi, H.

    2012-01-01

    Purpose: Dual-energy CT (DECT) is arguably the most accurate energy mapping technique in CT-based attenuation correction (CTAC) implemented on hybrid PET/CT systems. However, this approach is not attractive for clinical use owing to increased patient dose. The authors propose a novel energy mapping

  1. Temperature gain correction for CsI(Tl) detection systems based on digital pulse shape analysis

    International Nuclear Information System (INIS)

    In this paper we propose a pulse shape based method for monitoring the interior temperature of a CsI(Tl) crystal in order to correct the temperature dependence in the energy calibration of the corresponding detector system. The gain dependence on temperature of the CsI(Tl) detector was measured using both, a photomultiplier tube (PMT) and an avalanche photodiode (APD) readout photosensor. The analysis shows that the gain shifts due to temperature variations can be corrected to a precision of better than 1% with both the PMT and the APD, well below the CsI(Tl) intrinsic energy resolution for ~1 MeV γ-rays

  2. A new adaptive nonuniformity correction algorithm for infrared line scanner based on neural networks

    Institute of Scientific and Technical Information of China (English)

    Jing Sui; Liquan Dong; Weiqi Jin; Yayuan Zhang

    2007-01-01

    The striping pattern nonuniformity of the infrared line scanner (IRLS) severely limits the system performance. An adaptive nonuniformity correction (NUC) algorithm for IRLS using neural network is proposed.It uses a one-dimensional median filter to generate ideal output of network and can complete NUC by a single frame with a high correction level. Applications to both simulated and real infrared images show that the algorithm can obtain a satisfactory result with low complexity, no need of scene diversity or global motion between consecutive frames. It has the potential to realize real-time hardware-based applications.

  3. The generation algorithm of arbitrary polygon animation based on dynamic correction

    Directory of Open Access Journals (Sweden)

    Hou Ya Wei

    2016-01-01

    Full Text Available This paper, based on the key-frame polygon sequence, proposes a method that makes use of dynamic correction to develop continuous animation. Firstly we use quadratic Bezier curve to interpolate the corresponding sides vector of polygon sequence consecutive frame and realize the continuity of animation sequences. And then, according to Bezier curve characteristic, we conduct dynamic regulation to interpolation parameters and implement the changing smoothness. Meanwhile, we take use of Lagrange Multiplier Method to correct the polygon and close it. Finally, we provide the concrete algorithm flow and present numerical experiment results. The experiment results show that the algorithm acquires excellent effect.

  4. Gas sensor based on photoconductive electrospun titania nanofibres operating at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Zampetti, E., E-mail: emiliano.zampetti@artov.imm.cnr.it; Macagnano, A.; Bearzotti, A. [Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi (CNR IMM) (Italy)

    2013-04-15

    An important drawback of semiconductor gas sensors is their operating temperature that needs the use of heaters. To overcome this problem a prototyping sensor using titania nanofibres (with an average diameter of 50 nm) as sensitive membrane were fabricated by electrospinning directly on the transducer of the sensor. Exploiting the effect of titania photoconductivity, resistance variations upon gas interaction under continuous irradiation of ultra violet light were measured at room temperature. The resistive sensor response was evaluated towards ammonia, nitrogen dioxide and humidity. The sensor exhibited a higher response to ammonia than to nitrogen dioxide, especially for concentrations larger than 100 ppb. For 200 ppb of ammonia and nitrogen dioxide, the responses were {approx}2.8 and 1.5 %, respectively.

  5. New room temperature multiferroics on the base of single-phase nanostructured perovskites

    OpenAIRE

    Glinchuk, Maya D.; Eliseev, Eugene A.; Morozovska, Anna N.

    2014-01-01

    The theoretical description of the nanostructured Pb(Fe1/2Ta1/2)x(Zr1/2Ti1/2)1-xO3 (PFTx-PZT(1-x)) and Pb(Fe1/2Nb1/2)x(Zr1/2Ti1/2)1-xO3 (PFNx-PZT(1-x)) intriguing ferromagnetic, ferroelectric and magnetoelectric properties at temperatures higher than 100 K are absent to date. The goal of this work is to propose the theoretical description of the physical nature and the mechanisms of the aforementioned properties, including room temperature ferromagnetism, phase diagram dependence on the compo...

  6. Cross-interference correction and simultaneous multi-gas analysis based on infrared absorption

    Institute of Scientific and Technical Information of China (English)

    Sun You-Wen; Zeng Yi; Liu Wen-Qing; Xie Pin-Hua; Chan Ka-Lok; Li Xian-Xin; Wang Shi-Mei; Huang Shu-Hua

    2012-01-01

    In this paper,we present simultaneous multiple pollutant gases (CO2,CO,and NO) measurements by using the non-dispersive infrared (NDIR) technique.A cross-correlation correction method is proposed and used to correct the cross-interferences among the target gases.The calculation of calibration curves is based on least-square fittings with third-order polynomials,and the interference functions are approximated by linear curves.The pure absorbance of each gas is obtained by solving three simultaneous equations using the fitted interference functions.Through the interference correction,the signal created at each filter channel only depends on the absorption of the intended gas.Gas mixture samples with different concentrations of CO2,CO,and NO are pumped into the sample cell for analysis.The results show that the measurement error of each gas is less than 4.5%.

  7. Cross-interference correction and simultaneous multi-gas analysis based on infrared absorption

    International Nuclear Information System (INIS)

    In this paper, we present simultaneous multiple pollutant gases (CO2, CO, and NO) measurements by using the non-dispersive infrared (NDIR) technique. A cross-correlation correction method is proposed and used to correct the cross-interferences among the target gases. The calculation of calibration curves is based on least-square fittings with third-order polynomials, and the interference functions are approximated by linear curves. The pure absorbance of each gas is obtained by solving three simultaneous equations using the fitted interference functions. Through the interference correction, the signal created at each filter channel only depends on the absorption of the intended gas. Gas mixture samples with different concentrations of CO2, CO, and NO are pumped into the sample cell for analysis. The results show that the measurement error of each gas is less than 4.5%

  8. Laser assisted and hermetic room temperature bonding based on direct bonding technology

    Science.gov (United States)

    Haneveld, Jeroen; Tijssen, Peter; Oonk, Johannes; Olde Riekerink, Mark; Tigelaar, Hildebrand; van't Oever, Ronny; Blom, Marko

    2014-03-01

    A novel method for laser assisted room temperature bonding of two substrates is presented. The method enables the packaging of delicate (bio)structures and/or finished (MEMS) devices, as there is no need for a high temperature annealing process. This also allows the bonding of two substrates with non-matching thermal expansion coefficients. The basis of the presented technology is the ability to create a direct pre-bond between two substrates. These can be two glass substrates, of which one has a thin film metal coating (e.g. Cr. Ti, Ta, Au…), or a silicon-glass combination. After (aligned) pre-bonding of the two wafers, a laser (e.g. a Nd:YAG laser) is used to form a permanent bond line on the bond interface, using the metal layer as a light absorber (or the silicon, in the case of a glass-silicon combination). The permanent bond line width is in the order of 10-50μm. The use of a laser to form the permanent bond ensures a hermetic sealing of the total package; a distinctive advantage over other, more conventional methods of room temperature bonding (e.g. adhesive bonding). He-leak testing showed leak rates in the order of 10-9 mbar l/s. This meets the failure criteria of the MIL-STD-883H standard of 5x10-8 mbar l/s. An added functionality of the proposed method is the possibility to create electrical circuitry on the bond interface, using the laser to modify the metal interlayer, rendering it electrically non-conductive. Biocompatible packages are also possible, by choosing the appropriate interlayer material. This would allow for the fabrication of implantable packages.

  9. Iterative Dense Correspondence Correction Through Bundle Adjustment Feedback-Based Error Detection

    Energy Technology Data Exchange (ETDEWEB)

    Hess-Flores, M A; Duchaineau, M A; Goldman, M J; Joy, K I

    2009-11-23

    A novel method to detect and correct inaccuracies in a set of unconstrained dense correspondences between two images is presented. Starting with a robust, general-purpose dense correspondence algorithm, an initial pose estimate and dense 3D scene reconstruction are obtained and bundle-adjusted. Reprojection errors are then computed for each correspondence pair, which is used as a metric to distinguish high and low-error correspondences. An affine neighborhood-based coarse-to-fine iterative search algorithm is then applied only on the high-error correspondences to correct their positions. Such an error detection and correction mechanism is novel for unconstrained dense correspondences, for example not obtained through epipolar geometry-based guided matching. Results indicate that correspondences in regions with issues such as occlusions, repetitive patterns and moving objects can be identified and corrected, such that a more accurate set of dense correspondences results from the feedback-based process, as proven by more accurate pose and structure estimates.

  10. MRI-based motion correction of thoracic PET: initial comparison of acquisition protocols and correction strategies suitable for simultaneous PET/MRI systems

    Energy Technology Data Exchange (ETDEWEB)

    Dikaios, Nikolaos; Fryer, Tim D. [University of Cambridge, Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, Cambridge (United Kingdom); Izquierdo-Garcia, David; Mani, Venkatesh; Fayad, Zahi A. [Mount Sinai School of Medicine, Imaging Science Laboratories, Translational and Molecular Imaging Institute, Department of Radiology, New York, NY (United States); Graves, Martin J. [University of Cambridge, Department of Radiology, Cambridge (United Kingdom)

    2012-02-15

    Magnetic resonance imaging (MRI) acquired on equipment capable of simultaneous MRI and positron emission tomography (PET) could potentially provide the gold standard method for motion correction of PET. To assess the latter, in this study we compared fast 2D and 3D MRI of the torso and used deformation parameters from real MRI data to correct simulated PET data for respiratory motion. PET sinogram data were simulated using SimSET from a 4D pseudo-PET image series created by segmenting MR images acquired over a respiratory cycle. Motion-corrected PET images were produced using post-reconstruction registration (PRR) and motion-compensated image reconstruction (MCIR). MRI-based motion correction improved PET image quality at the lung-liver and lung-spleen boundaries and in the heart but little improvement was obtained where MRI contrast was low. The root mean square error in SUV units per voxel compared to a motion-free image was reduced from 0.0271 (no motion correction) to 0.0264 (PRR) and 0.0250 (MCIR). Motion correction using MRI can improve thoracic PET images but there are limitations due to the quality of fast MRI. (orig.)

  11. The effect of a rotary heat exchanger in room-based ventilation on indoor humidity in existing apartments in temperate climates

    DEFF Research Database (Denmark)

    Smith, Kevin Michael; Svendsen, Svend

    2016-01-01

    The investigation constructed and simulated moisture balance equations for single-room ventilation with a non-hygroscopic rotary heat exchanger. Based on literature, the study assumed that all condensed moisture in the exhaust subsequently evaporated into the supply. Simulations evaluated...... the sensitivity to influential parameters, such as infiltration rate, heat recovery, and indoor temperature. With a typical moisture production schedule, the rotary heat exchanger recovered excessive moisture from kitchens and bathrooms,which provided a mold risk. The rotary heat exchanger was only suitable...... for single-room ventilation of dry rooms, such as living rooms and bedrooms. The sensitivity analysis concluded that varying heat recovery or indoor temperature could limit indoor relative humidity in dry rooms when a moderate risk was present. The rotary heat exchanger also elevated the minimum relative...

  12. A software-based x-ray scatter correction method for breast tomosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Jia Feng, Steve Si; Sechopoulos, Ioannis [Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, and Department of Radiology and Imaging Sciences and Winship Cancer Institute, Emory University, 1701 Uppergate Drive Northeast, Suite 5018, Atlanta, Georgia 30322 (United States); Department of Radiology and Imaging Sciences, Hematology and Medical Oncology and Winship Cancer Institute, Emory University, 1701 Uppergate Drive Northeast, Suite 5018, Atlanta, Georgia 30322 (United States)

    2011-12-15

    Purpose: To develop a software-based scatter correction method for digital breast tomosynthesis (DBT) imaging and investigate its impact on the image quality of tomosynthesis reconstructions of both phantoms and patients. Methods: A Monte Carlo (MC) simulation of x-ray scatter, with geometry matching that of the cranio-caudal (CC) view of a DBT clinical prototype, was developed using the Geant4 toolkit and used to generate maps of the scatter-to-primary ratio (SPR) of a number of homogeneous standard-shaped breasts of varying sizes. Dimension-matched SPR maps were then deformed and registered to DBT acquisition projections, allowing for the estimation of the primary x-ray signal acquired by the imaging system. Noise filtering of the estimated projections was then performed to reduce the impact of the quantum noise of the x-ray scatter. Three dimensional (3D) reconstruction was then performed using the maximum likelihood-expectation maximization (MLEM) method. This process was tested on acquisitions of a heterogeneous 50/50 adipose/glandular tomosynthesis phantom with embedded masses, fibers, and microcalcifications and on acquisitions of patients. The image quality of the reconstructions of the scatter-corrected and uncorrected projections was analyzed by studying the signal-difference-to-noise ratio (SDNR), the integral of the signal in each mass lesion (integrated mass signal, IMS), and the modulation transfer function (MTF). Results: The reconstructions of the scatter-corrected projections demonstrated superior image quality. The SDNR of masses embedded in a 5 cm thick tomosynthesis phantom improved 60%-66%, while the SDNR of the smallest mass in an 8 cm thick phantom improved by 59% (p < 0.01). The IMS of the masses in the 5 cm thick phantom also improved by 15%-29%, while the IMS of the masses in the 8 cm thick phantom improved by 26%-62% (p < 0.01). Some embedded microcalcifications in the tomosynthesis phantoms were visible only in the scatter-corrected

  13. Locally adaptive regression filter-based infrared focal plane array non-uniformity correction

    Science.gov (United States)

    Li, Jia; Qin, Hanlin; Yan, Xiang; Huang, He; Zhao, Yingjuan; Zhou, Huixin

    2015-10-01

    Due to the limitations of the manufacturing technology, the response rates to the same infrared radiation intensity in each infrared detector unit are not identical. As a result, the non-uniformity of infrared focal plane array, also known as fixed pattern noise (FPN), is generated. To solve this problem, correcting the non-uniformity in infrared image is a promising approach, and many non-uniformity correction (NUC) methods have been proposed. However, they have some defects such as slow convergence, ghosting and scene degradation. To overcome these defects, a novel non-uniformity correction method based on locally adaptive regression filter is proposed. First, locally adaptive regression method is used to separate the infrared image into base layer containing main scene information and the detail layer containing detailed scene with FPN. Then, the detail layer sequence is filtered by non-linear temporal filter to obtain the non-uniformity. Finally, the high quality infrared image is obtained by subtracting non-uniformity component from original image. The experimental results show that the proposed method can significantly eliminate the ghosting and the scene degradation. The results of correction are superior to the THPF-NUC and NN-NUC in the aspects of subjective visual and objective evaluation index.

  14. Empirical mode decomposition-based motion artifact correction method for functional near-infrared spectroscopy

    Science.gov (United States)

    Gu, Yue; Han, Junxia; Liang, Zhenhu; Yan, Jiaqing; Li, Zheng; Li, Xiaoli

    2016-01-01

    Functional near-infrared spectroscopy (fNIRS) is a promising technique for monitoring brain activity. However, it is sensitive to motion artifacts. Many methods have been developed for motion correction, such as spline interpolation, wavelet filtering, and kurtosis-based wavelet filtering. We propose a motion correction method based on empirical mode decomposition (EMD), which is applied to segments of data identified as having motion artifacts. The EMD method is adaptive, data-driven, and well suited for nonstationary data. To test the performance of the proposed EMD method and to compare it with other motion correction methods, we used simulated hemodynamic responses added to real resting-state fNIRS data. The EMD method reduced mean squared error in 79% of channels and increased signal-to-noise ratio in 78% of channels. Moreover, it produced the highest Pearson's correlation coefficient between the recovered signal and the original signal, significantly better than the comparison methods (p<0.01, paired t-test). These results indicate that the proposed EMD method is a first choice method for motion artifact correction in fNIRS.

  15. Skeleton-based OPC application for DSA full chip mask correction

    Science.gov (United States)

    Schneider, L.; Farys, V.; Serret, E.; Fenouillet-Beranger, C.

    2015-09-01

    Recent industrial results around directed self-assembly (DSA) of block copolymers (BCP) have demonstrated the high potential of this technique [1-2]. The main advantage being cost reduction thanks to a reduced number of lithographic steps. Meanwhile, the associated correction for mask creation must account for the introduction of this new technique, maintaining a high level of accuracy and reliability. In order to create VIA (Vertical Interconnect Layer) layer, graphoepitaxy DSA can be used. The technique relies on the creation of a confinement guides where the BCP can separate into distinct regions and resulting patterns are etched in order to obtain an ordered series of VIA contact. The printing of the guiding pattern requires the use of classical lithography. Optical proximity correction (OPC) is applied to obtain the best suited guiding pattern allowing to match a specific design target. In this study, an original approach for DSA full chip mask optical proximity correction based on a skeleton representation of a guiding pattern is proposed. The cost function for an OPC process is based on minimizing the Central Placement Error (CPE), defined as the difference between an ideal skeleton target and a generated skeleton from a guiding contour. The high performance of this approach for DSA OPC full chip correction and its ability to minimize variability error on via placement is demonstrated and reinforced by the comparison with a rigorous model. Finally this Skeleton approach is highlighted as an appropriate tool for Design rules definition.

  16. Non-local means-based nonuniformity correction for infrared focal-plane array detectors

    Science.gov (United States)

    Yu, Hui; Zhang, Zhi-jie; Chen, Fu-sheng; Wang, Chen-sheng

    2014-11-01

    The infrared imaging systems are normally based on the infrared focal-plane array (IRFPA) which can be considered as an array of independent detectors aligned at the focal plane of the imaging system. Unfortunately, every detector on the IRFPA may have a different response to the same input infrared signal which is known as the nonuniformity problem. Then we can observe the fixed pattern noise (FPN) from the resulting images. Standard nonuniformity correction (NUC) methods need to be recalibrated after a short period of time due the temporal drift of the FPN. Scene-based nonuniformity correction (NUC) techniques eliminate the need for calibration by correction coefficients based on the scene being viewed. However, in the scene-based NUC method the problem of ghosting artifacts widely seriously decreases the image quality, which can degrade the performance of many applications such as target detection and track. This paper proposed an improved scene-based method based on the retina-like neural network approach. The method incorporates the use of non-local means (NLM) method into the estimation of the gain and the offset of each detector. This method can not only estimates the accurate correction coefficient but also restrict the ghosting artifacts efficiently. The proposed method relies on the use of NLM method which is a very successful image denoising method. And then the NLM used here can preserve the image edges efficiently and obtain a reliable spatial estimation. We tested the proposed NUC method by applying it to an IR sequence of frames. The performance of the proposed method was compared the other well-established adaptive NUC techniques.

  17. Al based ultra-fine eutectic with high room temperature plasticity and elevated temperature strength

    Energy Technology Data Exchange (ETDEWEB)

    Tiwary, C.S., E-mail: cst311@gmail.com [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, Karnataka (India); Kashyap, S. [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, Karnataka (India); Kim, D.H. [Center for Non-Crystalline Materials, Department of Metallurgical Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Chattopadhyay, K. [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, Karnataka (India)

    2015-07-15

    Developments of aluminum alloys that can retain strength at and above 250 °C present a significant challenge. In this paper we report an ultrafine scale Al–Fe–Ni eutectic alloy with less than 3.5 at% transition metals that exhibits room temperature ultimate tensile strength of ~400 MPa with a tensile ductility of 6–8%. The yield stress under compression at 300 °C was found to be 150 MPa. We attribute it to the refinement of the microstructure that is achieved by suction casting in copper mold. The characterization using scanning and transmission electron microscopy (SEM and TEM) reveals an unique composite structure that contains the Al–Al{sub 3}Ni rod eutectic with spacing of ~90 nm enveloped by a lamellar eutectic of Al–Al{sub 9}FeNi (~140 nm). Observation of subsurface deformation under Vickers indentation using bonded interface technique reveals the presence of extensive shear banding during deformation that is responsible for the origin of ductility. The dislocation configuration in Al–Al{sub 3}Ni eutectic colony indicates accommodation of plasticity in α-Al with dislocation accumulation at the α-Al/Al{sub 3}Ni interface boundaries. In contrast the dislocation activities in the intermetallic lamellae are limited and contain set of planner dislocations across the plates. We present a detailed analysis of the fracture surface to rationalize the origin of the high strength and ductility in this class of potentially promising cast alloy.

  18. Calculation of room temperature conductivity and mobility in tin-based topological insulator nanoribbons

    Energy Technology Data Exchange (ETDEWEB)

    Vandenberghe, William G., E-mail: wxv101020@utdallas.edu; Fischetti, Massimo V. [Department of Materials Science and Engineering, The University of Texas at Dallas, 800 W Campbell Rd. RL10, Richardson, Texas 75080 (United States)

    2014-11-07

    Monolayers of tin (stannanane) functionalized with halogens have been shown to be topological insulators. Using density functional theory (DFT), we study the electronic properties and room-temperature transport of nanoribbons of iodine-functionalized stannanane showing that the overlap integral between the wavefunctions associated to edge-states at opposite ends of the ribbons decreases with increasing width of the ribbons. Obtaining the phonon spectra and the deformation potentials also from DFT, we calculate the conductivity of the ribbons using the Kubo-Greenwood formalism and show that their mobility is limited by inter-edge phonon backscattering. We show that wide stannanane ribbons have a mobility exceeding 10{sup 6} cm{sup 2}/Vs. Contrary to ordinary semiconductors, two-dimensional topological insulators exhibit a high conductivity at low charge density, decreasing with increasing carrier density. Furthermore, the conductivity of iodine-functionalized stannanane ribbons can be modulated over a range of three orders of magnitude, thus rendering this material extremely interesting for classical computing applications.

  19. Al based ultra-fine eutectic with high room temperature plasticity and elevated temperature strength

    International Nuclear Information System (INIS)

    Developments of aluminum alloys that can retain strength at and above 250 °C present a significant challenge. In this paper we report an ultrafine scale Al–Fe–Ni eutectic alloy with less than 3.5 at% transition metals that exhibits room temperature ultimate tensile strength of ~400 MPa with a tensile ductility of 6–8%. The yield stress under compression at 300 °C was found to be 150 MPa. We attribute it to the refinement of the microstructure that is achieved by suction casting in copper mold. The characterization using scanning and transmission electron microscopy (SEM and TEM) reveals an unique composite structure that contains the Al–Al3Ni rod eutectic with spacing of ~90 nm enveloped by a lamellar eutectic of Al–Al9FeNi (~140 nm). Observation of subsurface deformation under Vickers indentation using bonded interface technique reveals the presence of extensive shear banding during deformation that is responsible for the origin of ductility. The dislocation configuration in Al–Al3Ni eutectic colony indicates accommodation of plasticity in α-Al with dislocation accumulation at the α-Al/Al3Ni interface boundaries. In contrast the dislocation activities in the intermetallic lamellae are limited and contain set of planner dislocations across the plates. We present a detailed analysis of the fracture surface to rationalize the origin of the high strength and ductility in this class of potentially promising cast alloy

  20. Fully printed, rapid-response sensors based on chemically modified graphene for detecting NO2 at room temperature.

    Science.gov (United States)

    Huang, Lei; Wang, Zhenping; Zhang, Jiankun; Pu, Jianlong; Lin, Youjie; Xu, Shuhua; Shen, Leo; Chen, Qi; Shi, Wangzhou

    2014-05-28

    Reduced graphene oxide (RGO) has proven to be effective in trace gas detection at room temperature ambient conditions. However, the slow response-recovery characteristic is a major hurdle for the RGO-based gas sensors. Herein, we report a gravure-printed chemoresistor-type NO2 sensor based on sulfonated RGO (S-RGO) decorated with Ag nanoparticles (Ag-S-RGO). Large amounts of silver nanoparticles with an average particle size of 10-20 nm were uniformly assembled on flat S-RGO surfaces. The printed Ag-S-RGO sensor possesses a high sensitivity and fast response-recovery characteristic over NO2 concentrations ranging from 0.5 to 50 ppm. Upon exposure to 50 ppm NO2 at room temperature, the Ag-S-RGO sensor shows a sensitivity of 74.6%, a response time of 12 s and a recovery time of 20 s. In addition, the Ag-S-RGO sensors exhibit satisfactory flexibility with an almost constant resistance after 1000 bending cycles. The printed and high-performance Ag-S-RGO sensors described here will be a good prospect in environmental monitoring of NO2. PMID:24806241

  1. Design of a beam shaping assembly and preliminary modelling of a treatment room for accelerator-based BNCT at CNEA

    Energy Technology Data Exchange (ETDEWEB)

    Burlon, A.A.; Girola, S. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, San Martin (Argentina)] [Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin, San Martin (Argentina); Valda, A.A., E-mail: valda@tandar.cnea.gov.ar [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, San Martin (Argentina)] [Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin, San Martin (Argentina); Minsky, D.M.; Kreiner, A.J. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, San Martin (Argentina)] [Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin, San Martin (Argentina)] [CONICET, Buenos Aires (Argentina); Sanchez, G. [Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin, San Martin (Argentina)

    2011-12-15

    This work reports on the characterisation of a neutron beam shaping assembly (BSA) prototype and on the preliminary modelling of a treatment room for BNCT within the framework of a research programme for the development and construction of an accelerator-based BNCT irradiation facility in Buenos Aires, Argentina. The BSA prototype constructed has been characterised by means of MCNP simulations as well as a set of experimental measurements performed at the Tandar accelerator at the National Atomic Energy Commission of Argentina. - Highlights: Black-Right-Pointing-Pointer Characterisation of a neutron beam shaping assembly for accelerator-based BNCT. Black-Right-Pointing-Pointer Measurements: total and epi-cadmium neutron fluxes and beam homogeneity. Black-Right-Pointing-Pointer Calculations: Monte Carlo simulations with the MCNP code. Black-Right-Pointing-Pointer Measured and calculated figure-of-merit parameters in agreement with those of IAEA. Black-Right-Pointing-Pointer Initial MCNP dose calculations for a treatment room to define future design actions.

  2. Room-temperature continuous-wave electrically injected InGaN-based laser directly grown on Si

    Science.gov (United States)

    Sun, Yi; Zhou, Kun; Sun, Qian; Liu, Jianping; Feng, Meixin; Li, Zengcheng; Zhou, Yu; Zhang, Liqun; Li, Deyao; Zhang, Shuming; Ikeda, Masao; Liu, Sheng; Yang, Hui

    2016-09-01

    Silicon photonics would greatly benefit from efficient, visible on-chip light sources that are electrically driven at room temperature. To fully utilize the benefits of large-scale, low-cost manufacturing foundries, it is highly desirable to grow direct bandgap III-V semiconductor lasers directly on Si. Here, we report the demonstration of a blue-violet (413 nm) InGaN-based laser diode grown directly on Si that operates under continuous-wave current injection at room temperature, with a threshold current density of 4.7 kA cm-2. The heteroepitaxial growth of GaN on Si is confronted with a large mismatch in both the lattice constant and the coefficient of thermal expansion, often resulting in a high density of defects and even microcrack networks. By inserting an Al-composition step-graded AlN/AlGaN multilayer buffer between the Si and GaN, we have not only successfully eliminated crack formation, but also effectively reduced the dislocation density. The result is the realization of a blue-violet InGaN-based laser on Si.

  3. Correcting Intensity Drift in X-ray Grating-based Phase Contrast Imaging

    International Nuclear Information System (INIS)

    X-ray phase-contrast imaging has become an attractive technique because it can deliver additional information on weakly absorbing materials. Grating-based phase contrast imaging with conventional x-ray source is a breakthrough in x-ray phase contrast imaging because it provides attenuation, refraction and scattering information simultaneously. Therefore, it has potential to be applied in medical and industrial applications. However, in actual experiments, we found that the photon intensity drift of the x-ray source would influence the final images, especially the refraction images. After analyzing the phase-stepping curve, we proposed a correction method to fix the problem due to the effect of intensity drift. The proposed correction method is successfully applied to grating-based phase-contrast imaging setup having un-stable x-ray source. The experimental results show that our method could solve this problem

  4. Waiting rooms /

    OpenAIRE

    Taylor, Rachel Lee

    2014-01-01

    Waiting Rooms is a collection of poetry broken into five sections, each containing a separate intention of form and content. These fives sections remain in conversation with the overarching themes of the collection as a whole. This collection maps the multiple types of violence perpetuated against women in domestic and institutional settings, as well as its historical presence in literary fiction/poetry and pop culture entertainment. Taking cues from Modernist poetry, Shakespearean plays, and...

  5. Production of a datolite-based heavy concrete for shielding nuclear reactors and megavoltage radiotherapy rooms

    International Nuclear Information System (INIS)

    Biological shielding of nuclear reactors has always been a great concern and decreasing the complexity and expense of these installations is of great interest. In this study, we used datolite and galena minerals for production of a high performance heavy concrete. Materials and Methods: Datolite and galena minerals which can be found in many parts of Iran were used in the concrete mix design. To measure the gamma radiation attenuation of the Datolite and galena concrete samples, they were exposed to both narrow and wide beams of gamma rays emitted from a cobalt-60 radiotherapy unit. An Am-Be neutron source was used for assessing the shielding properties of the samples against neutrons. To test the compression strengths, both types of concrete mixes (Datolite and galena and ordinary concrete) were investigated. Results: The concrete samples had a density of 4420-4650 kg/m3 compared to that of ordinary concrete (2300-2500 kg/m3) or barite high density concrete (up to 3500 kg/m3). The measured half value layer thickness of the Datolite and galena concrete samples for cobalt-60 gamma rays was much less than that of ordinary concrete (2.56 cm compared to 6.0 cm). Furthermore, the galena concrete samples had a significantly higher compressive strength as well as 20% more neutron absorption. Conclusion: The Datolite and galena concrete samples showed good shielding/engineering properties in comparison with other reported samples made, using high-density materials other than depleted uranium. It is also more economic than the high-density concretes. Datolite and galena concrete may be a suitable option for shielding nuclear reactors and megavoltage radiotherapy rooms.

  6. [Correction Method of Atmospheric Scattering Effect Based on Three Spectrum Bands].

    Science.gov (United States)

    Ye, Han-han; Wang, Xian-hua; Jiang, Xin-hua; Bu, Ting-ting

    2016-03-01

    As a major error of CO2 retrieval, atmospheric scattering effect hampers the application of satellite products. Effect of aerosol and combined effect of aerosol and ground surface are important source of atmospheric scattering, so it needs comprehensive consideration of scattering effect from aerosol and ground surface. Based on the continuum, strong and weak absorption part of three spectrum bands O2-A, CO2 1.6 μm and 2.06 μm, information of aerosol and albedo was analyzed, and improved full physics retrieval method was proposed, which can retrieve aerosol and albedo simultaneously to correct the scattering effect. Simulation study on CO2 error caused by aerosol and ground surface albedo CO2 error by correction method was carried out. CO2 error caused by aerosol optical depth and ground surface albedo can reach up to 8%, and CO2 error caused by different types of aerosol can reach up to 10%, while these two types of error can be controlled within 1% and 2% separately by this correction method, which shows that the method can correct the scattering effect effectively. Through evaluation of the results, the potential of this method for high precision satellite data retrieval is obvious, meanwhile, some problems which need to be noticed in real application were also pointed out. PMID:27400493

  7. Modular correction method of bending elastic modulus based on sliding behavior of contact point

    International Nuclear Information System (INIS)

    During the three-point bending test, the sliding behavior of the contact point between the specimen and supports was observed, the sliding behavior was verified to affect the measurements of both deflection and span length, which directly affect the calculation of the bending elastic modulus. Based on the Hertz formula to calculate the elastic contact deformation and the theoretical calculation of the sliding behavior of the contact point, a theoretical model to precisely describe the deflection and span length as a function of bending load was established. Moreover, a modular correction method of bending elastic modulus was proposed, via the comparison between the corrected elastic modulus of three materials (H63 copper–zinc alloy, AZ31B magnesium alloy and 2026 aluminum alloy) and the standard modulus obtained from standard uniaxial tensile tests, the universal feasibility of the proposed correction method was verified. Also, the ratio of corrected to raw elastic modulus presented a monotonically decreasing tendency as the raw elastic modulus of materials increased. (technical note)

  8. Library-based scatter correction for dedicated cone beam breast CT: a feasibility study

    Science.gov (United States)

    Shi, Linxi; Vedantham, Srinivasan; Karellas, Andrew; Zhu, Lei

    2016-04-01

    Purpose: Scatter errors are detrimental to cone-beam breast CT (CBBCT) accuracy and obscure the visibility of calcifications and soft-tissue lesions. In this work, we propose practical yet effective scatter correction for CBBCT using a library-based method and investigate its feasibility via small-group patient studies. Method: Based on a simplified breast model with varying breast sizes, we generate a scatter library using Monte-Carlo (MC) simulation. Breasts are approximated as semi-ellipsoids with homogeneous glandular/adipose tissue mixture. On each patient CBBCT projection dataset, an initial estimate of scatter distribution is selected from the pre-computed scatter library by measuring the corresponding breast size on raw projections and the glandular fraction on a first-pass CBBCT reconstruction. Then the selected scatter distribution is modified by estimating the spatial translation of the breast between MC simulation and the clinical scan. Scatter correction is finally performed by subtracting the estimated scatter from raw projections. Results: On two sets of clinical patient CBBCT data with different breast sizes, the proposed method effectively reduces cupping artifact and improves the image contrast by an average factor of 2, with an efficient processing time of 200ms per conebeam projection. Conclusion: Compared with existing scatter correction approaches on CBBCT, the proposed library-based method is clinically advantageous in that it requires no additional scans or hardware modifications. As the MC simulations are pre-computed, our method achieves a high computational efficiency on each patient dataset. The library-based method has shown great promise as a practical tool for effective scatter correction on clinical CBBCT.

  9. Dominant color extraction based color correction for multi-view images

    Institute of Scientific and Technical Information of China (English)

    Feng Shao; Mei Yu; Gangyi Jiang

    2007-01-01

    Color information is very important in setting the style of images. In this paper, a color correction method based on dominant color extraction is proposed to eliminate the color inconsistence between multi-view images. With the theory of basic color categories, dominant colors from the categories are extracted for reference image and input image, and then the corresponding color mapping relationships are built.Experimental results show that the proposed method is quite effective.

  10. Room Temperature ppb Level Chlorine Gas Sensor Based on Copper (II) 1, 4, 8, 11, 15, 18, 22, 25-octabutoxy-29 H, 31 H-phthalocyanine Films

    Science.gov (United States)

    Bedi, R. K.; Saini, Rajan; Mahajan, Aman

    2010-12-01

    Spin coating technique has been used to fabricate room temperature chlorine gas sensor based on copper (II) 1, 4, 8, 11, 15, 18, 22, 25-octabutoxy-29 H, 31 H-phthalocyanine (CuPc(OBu)8) films. Gas sensor shows a response of 185% to few parts per billion level of Cl2 gas with response time of 9.5 minutes at room temperature. The interactions between sensor and analytes followed first order kinetics with rate constant 0.01≤k≤0.02. The chemiresistive sensor showed very good stability at room temperature over a long period of time.

  11. Room Temperature ppb Level Chlorine Gas Sensor Based on Copper (II) 1, 4, 8, 11, 15, 18, 22, 25-octabutoxy-29 H, 31 H-phthalocyanine Films

    International Nuclear Information System (INIS)

    Spin coating technique has been used to fabricate room temperature chlorine gas sensor based on copper (II) 1, 4, 8, 11, 15, 18, 22, 25-octabutoxy-29 H, 31 H-phthalocyanine (CuPc(OBu)8) films. Gas sensor shows a response of 185% to few parts per billion level of Cl2 gas with response time of 9.5 minutes at room temperature. The interactions between sensor and analytes followed first order kinetics with rate constant 0.01≤k≤0.02. The chemiresistive sensor showed very good stability at room temperature over a long period of time.

  12. A new sensor for ammonia based on cyanidin-sensitized titanium dioxide film operating at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Xiao-wei, Huang [School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, 212013 Zhenjiang, Jiangsu (China); Xiao-bo, Zou, E-mail: zou_xiaobo@ujs.edu.cn [School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, 212013 Zhenjiang, Jiangsu (China); Key Laboratory of Modern Agricultural Equipment and Technology, 301 Xuefu Road, 212013 Zhenjiang, Jiangsu (China); Ji-yong, Shi; Jie-wen, Zhao; Yanxiao, Li [School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, 212013 Zhenjiang, Jiangsu (China); Limin, Hao; Jianchun, Zhang [The Research Center of China Hemp Materials, Beijing (China)

    2013-07-17

    Graphical abstract: -- Highlights: •TiO{sub 2} was prepared by sol–gel method film and then functionalized with the cyanidin dye. •The morphology and the absorption spectra of films were examined. •The hybrid organic–inorganic formed film here can detect ammonia reversibly at room temperature. •The low humidity could promote the sensitivity of the sensors. -- Abstract: Design and fabrication of an ammonia sensor operating at room temperature based on pigment-sensitized TiO{sub 2} films was described. TiO{sub 2} was prepared by sol–gel method and deposited on glass slides containing gold electrodes. Then, the film immersed in a 2.5 × 10{sup −4} M ethanol solution of cyanidin to absorb the pigment. The hybrid organic–inorganic formed film here can detect ammonia reversibly at room temperature. The relative change resistance of the films at a potential difference of 1.5 V is determined when the films are exposed to atmospheres containing ammonia vapors with concentrations over the range 10–50 ppm. The relative change resistance, S, of the films increased almost linearly with increasing concentrations of ammonia (r = 0.92). The response time to increasing concentrations of the ammonia is about 180–220 s, and the corresponding values for decreasing concentrations 240–270 s. At low humidity, ammonia could be ionized by the cyanidin on the TiO{sub 2} film and thereby decrease in the proton concentration at the surface. Consequently, more positively charged holes at the surface of the TiO{sub 2} have to be extracted to neutralize the adsorbed cyanidin and water film. The resistance response to ammonia of the sensors was nearly independent on temperature from 10 to 50 °C. These results are not actually as good as those reported in the literature, but this preliminary work proposes simpler and cheaper processes to realize NH{sub 3} sensor for room temperature applications.

  13. Subject identification via ECG fiducial-based systems: influence of the type of QT interval correction.

    Science.gov (United States)

    Gargiulo, Francesco; Fratini, Antonio; Sansone, Mario; Sansone, Carlo

    2015-10-01

    Electrocardiography (ECG) has been recently proposed as biometric trait for identification purposes. Intra-individual variations of ECG might affect identification performance. These variations are mainly due to Heart Rate Variability (HRV). In particular, HRV causes changes in the QT intervals along the ECG waveforms. This work is aimed at analysing the influence of seven QT interval correction methods (based on population models) on the performance of ECG-fiducial-based identification systems. In addition, we have also considered the influence of training set size, classifier, classifier ensemble as well as the number of consecutive heartbeats in a majority voting scheme. The ECG signals used in this study were collected from thirty-nine subjects within the Physionet open access database. Public domain software was used for fiducial points detection. Results suggested that QT correction is indeed required to improve the performance. However, there is no clear choice among the seven explored approaches for QT correction (identification rate between 0.97 and 0.99). MultiLayer Perceptron and Support Vector Machine seemed to have better generalization capabilities, in terms of classification performance, with respect to Decision Tree-based classifiers. No such strong influence of the training-set size and the number of consecutive heartbeats has been observed on the majority voting scheme. PMID:26143963

  14. Acoustic echoes reveal room shape.

    Science.gov (United States)

    Dokmanic, Ivan; Parhizkar, Reza; Walther, Andreas; Lu, Yue M; Vetterli, Martin

    2013-07-23

    Imagine that you are blindfolded inside an unknown room. You snap your fingers and listen to the room's response. Can you hear the shape of the room? Some people can do it naturally, but can we design computer algorithms that hear rooms? We show how to compute the shape of a convex polyhedral room from its response to a known sound, recorded by a few microphones. Geometric relationships between the arrival times of echoes enable us to "blindfoldedly" estimate the room geometry. This is achieved by exploiting the properties of Euclidean distance matrices. Furthermore, we show that under mild conditions, first-order echoes provide a unique description of convex polyhedral rooms. Our algorithm starts from the recorded impulse responses and proceeds by learning the correct assignment of echoes to walls. In contrast to earlier methods, the proposed algorithm reconstructs the full 3D geometry of the room from a single sound emission, and with an arbitrary geometry of the microphone array. As long as the microphones can hear the echoes, we can position them as we want. Besides answering a basic question about the inverse problem of room acoustics, our results find applications in areas such as architectural acoustics, indoor localization, virtual reality, and audio forensics. PMID:23776236

  15. Large magneto-conductance and magneto-electroluminescence in exciplex-based organic light-emitting diodes at room temperature

    Science.gov (United States)

    Ling, Yongzhou; Lei, Yanlian; Zhang, Qiaoming; Chen, Lixiang; Song, Qunliang; Xiong, Zuhong

    2015-11-01

    In this work, we report on large magneto-conductance (MC) over 60% and magneto-electroluminescence (MEL) as high as 112% at room temperature in an exciplex-based organic light-emitting diode (OLED) with efficient reverse intersystem crossing (ISC). The large MC and MEL are individually confirmed by the current density-voltage characteristics and the electroluminescence spectra under various magnetic fields. We proposed that this type of magnetic field effect (MFE) is governed by the field-modulated reverse ISC between the singlet and triplet exciplex. The temperature-dependent MFEs reveal that the small activation energy of reverse ISC accounts for the large MFEs in the present exciplex-based OLEDs.

  16. Compact CH4 sensor system based on a continuous-wave, low power consumption, room temperature interband cascade laser

    Science.gov (United States)

    Dong, Lei; Li, Chunguang; Sanchez, Nancy P.; Gluszek, Aleksander K.; Griffin, Robert J.; Tittel, Frank K.

    2016-01-01

    A tunable diode laser absorption spectroscopy-based methane sensor, employing a dense-pattern multi-pass gas cell and a 3.3 μm, CW, DFB, room temperature interband cascade laser (ICL), is reported. The optical integration based on an advanced folded optical path design and an efficient ICL control system with appropriate electrical power management resulted in a CH4 sensor with a small footprint (32 × 20 × 17 cm3) and low-power consumption (6 W). Polynomial and least-squares fit algorithms are employed to remove the baseline of the spectral scan and retrieve CH4 concentrations, respectively. An Allan-Werle deviation analysis shows that the measurement precision can reach 1.4 ppb for a 60 s averaging time. Continuous measurements covering a seven-day period were performed to demonstrate the stability and robustness of the reported CH4 sensor system.

  17. Room temperature formaldehyde sensors with enhanced performance, fast response and recovery based on zinc oxide quantum dots/graphene nanocomposites

    Science.gov (United States)

    Huang, Qingwu; Zeng, Dawen; Li, Huayao; Xie, Changsheng

    2012-08-01

    Novel zinc oxide quantum dots (ZnO QDs) decorated graphene nanocomposites were fabricated by a facile solution-processed method. ZnO QDs with a size ca. 5 nm are nucleated and grown on the surface of the graphene template, and its distribution density can be easily controlled by the reaction time and precursor concentration. The ZnO QDs/graphene nanocomposite materials enhance formaldehyde sensing properties by 4 times compared to pure graphene at room temperature. Moreover, the sensors based on the nanocomposites have fast response (ca. 30 seconds) and recovery (ca. 40 seconds) behavior, excellent room temperature selectivity and stability. The gas sensing enhancement is attributed to the synergistic effect of graphene and ZnO QDs. The electron transfer between the ZnO QDs and the graphene is due to oxidation process of the analyzed gas on the ZnO QDs' surface. This proposed gas sensing mechanism is experimentally proved by DRIFT spectra results. The ZnO QDs/graphene nanocomposites sensors have potential applications for monitoring air pollution, especially for harmful and toxic VOCs (volatile organic compounds).

  18. Room temperature chemical synthesis of highly oriented PbSe nanotubes based on negative free energy of formation

    Energy Technology Data Exchange (ETDEWEB)

    Sankapal, B.R., E-mail: brsankapal@rediffmail.com [Thin Film and Nano Science Laboratory, Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon 425 001 (MS) (India); Ladhe, R.D.; Salunkhe, D.B.; Baviskar, P.K. [Thin Film and Nano Science Laboratory, Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon 425 001 (MS) (India); Gupta, V.; Chand, S. [Organic and Hybrid Solar Cell, Physics of Energy Harvesting Division, Dr. K.S. Krishnan Marg, National Physical Laboratory, New Delhi 110012 (India)

    2011-10-13

    Highlights: > Simple, inexpensive and room temperature chemical synthesis route. > Highly oriented PbSe nanotubes from Cd(OH){sub 2} nanowires through lead hydroxination. > The process was template free without the use of any capping agent. > Reaction kinetics was accomplished due to more negative free energy of formation. > The ion exchange mechanism due to difference in the solubility products. - Abstract: The sacrificial template free chemical synthesis of PbSe nanotubes at room temperature has been performed by lead hydroxination from cadmium hydroxide nanowires. This process was based on the ion exchange reaction to replace Cd{sup 2+} with Pb{sup 2+} ions from hydroxyl group followed by replacement of hydroxyl group with selenium ions. The reaction kinetics was accomplished due to more negative free energy of formation and thus the difference in the solubility products. The formed nanotubes were inclusive of Pb and Se with proper inter-chemical bonds with preferred orientations having diameter in tens of nanometer. These nanotubes can have future applications in electronic, optoelectronics and photovoltaic's as well.

  19. Level of Service Analysis Based on Maximum Number of Passengers in Waiting Room of Railway Passenger Station Using Arena Simulation

    Directory of Open Access Journals (Sweden)

    Bo Yang

    2015-01-01

    Full Text Available The level of service is an important aspect of the operation and management at a railway passenger station. Particularly, the level of service in waiting room (LOSWR is one of the most important influential factors in deciding passengers’ satisfaction. This paper proposes a model for finding the LOSWR based on the maximum number of passengers, and an Arena simulation model that simulates passengers’ aggregation behaviors in the waiting room is presented for analyzing the LOSWR. Through the simulation, we demonstrate how the passenger advanced arrival time and the accompany rate influence the maximum number of passengers and the LOSWR. In addition, the simulation also illustrates the effect utilities and the priority of different measures that can be used to improve the LOSWR. In detail, the simulation results demonstrate that the passenger advanced arrival time and advanced check-out time have much stronger effect utilities on the maximum number of passengers and the LOSWR than other discussed factors. The simulation suggests that the Arena is an effective simulation platform for analyzing complex passengers-related behaviors at railway passenger station.

  20. Real-time measurements of atmospheric CO using a continuous-wave room temperature quantum cascade laser based spectrometer.

    Science.gov (United States)

    Li, Jingsong; Parchatka, Uwe; Königstedt, Rainer; Fischer, Horst

    2012-03-26

    A compact, mobile mid-infrared laser spectrometer based on a thermoelectrically (TE) cooled continuous-wave room temperature quantum cascade laser and TE-cooled detectors has been newly developed to demonstrate the applicability of high sensitivity and high precision measurements of atmospheric CO. Performance of the instrument was examined with periodic measurements of reference sample and ambient air at 1 Hz sampling rate and a 1-hourly calibration cycle. The typical precision evaluated from replicate measurements of reference sample over the course of 66-h is 1.41 ppbv. With the utilization of wavelet filtering to improve the spectral SNR and minimize the dispersion of concentration values, a better precision of 0.88 ppbv and a lower detection limit of ~0.4 ppbv with sub-second averaging time have been achieved without reducing the fast temporal response. Allan variance analysis indicates a CO measurement precision of ~0.28 ppbv for optimal integration time of approximate 50 s. The absolute accuracy is limited by the calibration gas standard. This completely thermoelectrically cooled system shows the capability of long-term, unattended and continuous operation at room temperature without complicated cryogenic cooling. PMID:22453438

  1. Ultrafast cone-beam CT scatter correction with GPU-based Monte Carlo simulation

    Directory of Open Access Journals (Sweden)

    Yuan Xu

    2014-03-01

    Full Text Available Purpose: Scatter artifacts severely degrade image quality of cone-beam CT (CBCT. We present an ultrafast scatter correction framework by using GPU-based Monte Carlo (MC simulation and prior patient CT image, aiming at automatically finish the whole process including both scatter correction and reconstruction within 30 seconds.Methods: The method consists of six steps: 1 FDK reconstruction using raw projection data; 2 Rigid Registration of planning CT to the FDK results; 3 MC scatter calculation at sparse view angles using the planning CT; 4 Interpolation of the calculated scatter signals to other angles; 5 Removal of scatter from the raw projections; 6 FDK reconstruction using the scatter-corrected projections. In addition to using GPU to accelerate MC photon simulations, we also use a small number of photons and a down-sampled CT image in simulation to further reduce computation time. A novel denoising algorithm is used to eliminate MC noise from the simulated scatter images caused by low photon numbers. The method is validated on one simulated head-and-neck case with 364 projection angles.Results: We have examined variation of the scatter signal among projection angles using Fourier analysis. It is found that scatter images at 31 angles are sufficient to restore those at all angles with < 0.1% error. For the simulated patient case with a resolution of 512 × 512 × 100, we simulated 5 × 106 photons per angle. The total computation time is 20.52 seconds on a Nvidia GTX Titan GPU, and the time at each step is 2.53, 0.64, 14.78, 0.13, 0.19, and 2.25 seconds, respectively. The scatter-induced shading/cupping artifacts are substantially reduced, and the average HU error of a region-of-interest is reduced from 75.9 to 19.0 HU.Conclusion: A practical ultrafast MC-based CBCT scatter correction scheme is developed. It accomplished the whole procedure of scatter correction and reconstruction within 30 seconds.----------------------------Cite this

  2. Comparison of MR-based attenuation correction and CT-based attenuation correction of whole-body PET/MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo-Garcia, David [Mount Sinai School of Medicine, Translational and Molecular Imaging Institute, New York, NY (United States); Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA (United States); Sawiak, Stephen J. [University of Cambridge, Wolfson Brain Imaging Centre, Cambridge (United Kingdom); Knesaurek, Karin; Machac, Joseph [Mount Sinai School of Medicine, Division of Nuclear Medicine, Department of Radiology, New York, NY (United States); Narula, Jagat [Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); Fuster, Valentin [Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); The Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid (Spain); Fayad, Zahi A. [Mount Sinai School of Medicine, Translational and Molecular Imaging Institute, New York, NY (United States); Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); Mount Sinai School of Medicine, Department of Radiology, New York, NY (United States)

    2014-08-15

    The objective of this study was to evaluate the performance of the built-in MR-based attenuation correction (MRAC) included in the combined whole-body Ingenuity TF PET/MR scanner and compare it to the performance of CT-based attenuation correction (CTAC) as the gold standard. Included in the study were 26 patients who underwent clinical whole-body FDG PET/CT imaging and subsequently PET/MR imaging (mean delay 100 min). Patients were separated into two groups: the alpha group (14 patients) without MR coils during PET/MR imaging and the beta group (12 patients) with MR coils present (neurovascular, spine, cardiac and torso coils). All images were coregistered to the same space (PET/MR). The two PET images from PET/MR reconstructed using MRAC and CTAC were compared by voxel-based and region-based methods (with ten regions of interest, ROIs). Lesions were also compared by an experienced clinician. Body mass index and lung density showed significant differences between the alpha and beta groups. Right and left lung densities were also significantly different within each group. The percentage differences in uptake values using MRAC in relation to those using CTAC were greater in the beta group than in the alpha group (alpha group -0.2 ± 33.6 %, R{sup 2} = 0.98, p < 0.001; beta group 10.31 ± 69.86 %, R{sup 2} = 0.97, p < 0.001). In comparison to CTAC, MRAC led to underestimation of the PET values by less than 10 % on average, although some ROIs and lesions did differ by more (including the spine, lung and heart). The beta group (imaged with coils present) showed increased overall PET quantification as well as increased variability compared to the alpha group (imaged without coils). PET data reconstructed with MRAC and CTAC showed some differences, mostly in relation to air pockets, metallic implants and attenuation differences in large bone areas (such as the pelvis and spine) due to the segmentation limitation of the MRAC method. (orig.)

  3. Comparison of MR-based attenuation correction and CT-based attenuation correction of whole-body PET/MR imaging

    International Nuclear Information System (INIS)

    The objective of this study was to evaluate the performance of the built-in MR-based attenuation correction (MRAC) included in the combined whole-body Ingenuity TF PET/MR scanner and compare it to the performance of CT-based attenuation correction (CTAC) as the gold standard. Included in the study were 26 patients who underwent clinical whole-body FDG PET/CT imaging and subsequently PET/MR imaging (mean delay 100 min). Patients were separated into two groups: the alpha group (14 patients) without MR coils during PET/MR imaging and the beta group (12 patients) with MR coils present (neurovascular, spine, cardiac and torso coils). All images were coregistered to the same space (PET/MR). The two PET images from PET/MR reconstructed using MRAC and CTAC were compared by voxel-based and region-based methods (with ten regions of interest, ROIs). Lesions were also compared by an experienced clinician. Body mass index and lung density showed significant differences between the alpha and beta groups. Right and left lung densities were also significantly different within each group. The percentage differences in uptake values using MRAC in relation to those using CTAC were greater in the beta group than in the alpha group (alpha group -0.2 ± 33.6 %, R2 = 0.98, p 2 = 0.97, p < 0.001). In comparison to CTAC, MRAC led to underestimation of the PET values by less than 10 % on average, although some ROIs and lesions did differ by more (including the spine, lung and heart). The beta group (imaged with coils present) showed increased overall PET quantification as well as increased variability compared to the alpha group (imaged without coils). PET data reconstructed with MRAC and CTAC showed some differences, mostly in relation to air pockets, metallic implants and attenuation differences in large bone areas (such as the pelvis and spine) due to the segmentation limitation of the MRAC method. (orig.)

  4. The correction of the distortion of human face based on three-dimensional modeling methods

    Science.gov (United States)

    Ye, Qingmin; Chen, Kuo; Feng, Huajun; Xu, Zhihai; Li, Qi

    2015-08-01

    When the human face is on the edge of field of the camera which has a large view, serious deformation will be captured. To correct the distortion of the human face, we present an approach based on setting up a 3D model. Firstly, we construct 3D target face modeling by using the data and depth information of the standard human face, which is set up by the three-dimensional model with three-dimensional Gaussian function with sectional type. According to the size of the face in the image and the parameters of the camera, we can obtain the information of relative position and depth of the human face. Then by translating the virtual camera axis to the center of the face, we can achieve the goal to correct the distortion of the face based on the theory of three-dimensional imaging. Finally, we have made a lot of experiments, and we study the influence of parameters of the 3D model of human face. The result indicates that the method presented by this paper can play an effective role in correcting the distortion of the face in the edge of the view, and we can get better results if the model appreciates the real human face.

  5. A new algorithm and results of ionospheric delay correction for satellite-based augmentation system

    Science.gov (United States)

    Huang, Z.; Yuan, H.

    Ionospheric delay resulted from radio signals traveling ionosphere is the largest source of errors for single-frequency users of the Global Positioning System GPS In order to improve users position accuracy augmentation systems based on satellite have been developed to provide accurate calibration since the nineties A famous one is Wide Area Augmentation System WAAS which is aimed to the efficiency of navigation over the conterminous United States and has been operating successfully so far The main idea of ionospheric correction algorithm for WAAS is to establish ionospheric grid model i e ionosphere is discretized into a set of regularly-spaced intervals in latitude and longitude at an altitude of 350km above the earth surface The users calculate their pseudoranges by interpolating estimates of vertical ionospheric delay modeled at ionospheric grid points The Chinese crust deformation monitoring network has been established since the eighties and now it is in good operation with 25 permanent GPS stations which provide feasibility to construct similar satellite-based augmentation system SBAS in China For the west region of China the distribution of stations is relatively sparse not to ensure sufficient data If we follow the ionospheric grid correction algorithm some grid points can t obtain their estimate and lost availability Consequently ionospheric correction measurement on the users situated in that region is inestimable which constitute a fatal threat to navigation users In this paper we presented a new algorithm that

  6. Distortion correction algorithm for UAV remote sensing image based on CUDA

    International Nuclear Information System (INIS)

    In China, natural disasters are characterized by wide distribution, severe destruction and high impact range, and they cause significant property damage and casualties every year. Following a disaster, timely and accurate acquisition of geospatial information can provide an important basis for disaster assessment, emergency relief, and reconstruction. In recent years, Unmanned Aerial Vehicle (UAV) remote sensing systems have played an important role in major natural disasters, with UAVs becoming an important technique of obtaining disaster information. UAV is equipped with a non-metric digital camera with lens distortion, resulting in larger geometric deformation for acquired images, and affecting the accuracy of subsequent processing. The slow speed of the traditional CPU-based distortion correction algorithm cannot meet the requirements of disaster emergencies. Therefore, we propose a Compute Unified Device Architecture (CUDA)-based image distortion correction algorithm for UAV remote sensing, which takes advantage of the powerful parallel processing capability of the GPU, greatly improving the efficiency of distortion correction. Our experiments show that, compared with traditional CPU algorithms and regardless of image loading and saving times, the maximum acceleration ratio using our proposed algorithm reaches 58 times that using the traditional algorithm. Thus, data processing time can be reduced by one to two hours, thereby considerably improving disaster emergency response capability

  7. Should dosing of rocuronium in obese patients be based on ideal or corrected body weight?

    DEFF Research Database (Denmark)

    Meyhoff, Christian S; Lund, Jørgen; Jenstrup, Morten T;

    2009-01-01

    BACKGROUND: Pharmacokinetic studies in obese patients suggest that dosing of rocuronium should be based on ideal body weight (IBW). This may, however, result in a prolonged onset time or compromised conditions for tracheal intubation. In this study, we compared onset time, conditions for tracheal...... intubation, and duration of action in obese patients when the intubation dose of rocuronium was based on three different weight corrections. METHODS: Fifty-one obese patients, with a median (range) body mass index of 44 (34-72) kg/m2, scheduled for laparoscopic gastric banding or gastric bypass under...

  8. The Influence of Rehabilitative and Punishment Ideology on Correctional Officers' Perceptions of Informal Bases of Power.

    Science.gov (United States)

    Gordon, Jill A; Stichman, Amy J

    2016-10-01

    Maintaining order is a key goal for prison managers. Much of the research on order maintenance focuses, however, on disruptions of order, even when order is more common. Examining factors related to perceptions on how officers get inmates to comply is, therefore, an important consideration. Using a survey of correctional officers from a Mid-Atlantic state, this study considers three dimensions of French and Raven's theory on the bases of power. The focus is to examine correctional orientation and compliance regarding three dimensions of power that rely on informal control and relationships. The results indicate that officers' belief in rehabilitative ideals is consistently related to the dimensions of legitimate, referent, and expert control. Other individual and organizational factors are also related to dimensions of power. Implications for policies and for future research are discussed.

  9. A Novel Dynamic Bandwidth Allocation Algorithm with Correction-based the Multiple Traffic Prediction in EPON

    Directory of Open Access Journals (Sweden)

    Ziyi Fu

    2012-10-01

    Full Text Available According to the upstream TDM in the system of Ethernet passive optical network (EPON, this paper proposes a novel dynamic bandwidth allocation algorithm which supports the mechanism with correction-based the multiple services estimation. To improve the real-time performance of the bandwidth allocation, this algorithm forecasts the traffic of high priority services, and then pre-allocate bandwidth for various priority services is corrected according to Gaussian distribution characteristics, which will make traffic prediction closer to the real traffic. The simulation results show that proposed algorithm is better than the existing DBA algorithm. Not only can it meet the delay requirement of high priority services, but also control the delay abnormity of low priority services. In addition, with rectification scheme, it obviously improves the bandwidth utilization.

  10. Errors in Thermographic Camera Measurement Caused by Known Heat Sources and Depth Based Correction

    Directory of Open Access Journals (Sweden)

    Mark Christian E. Manuel

    2016-03-01

    Full Text Available Thermal imaging has shown to be a better tool for the quantitative measurement of temperature than single spot infrared thermometers. However, thermographic cameras can encounter errors in acquiring accurate temperature measurements in the presence of other environmental heat sources. Some of these errors arise due to the inability of the thermal camera to detect objects and features in the infrared domain. In this paper, the thermal image is registered as a stereo image from a Kinect system prior to depth-based correction. Experiments demonstrating the error are presented together with the determination of the measurement errors under prior knowledge of the thermographed scene. The proposed correction scheme improves the accuracy of the thermal image through augmentation using the Kinect system.

  11. Three dimensional deformation of dry-stored complete denture base at room temperature

    Science.gov (United States)

    2016-01-01

    PURPOSE The aim of this study was to evaluate whether there is any typical deformation pattern existing in complete denture when it was dried by using the 3D scanner and surface matching program. MATERIALS AND METHODS A total of 28 denture bases were fabricated with heat curing acrylic resin (each 14 upper and lower denture bases), and 14 denture bases (each 7 upper and lower denture bases) were stored in the water bottle (water stored), and another 14 denture bases were stored in the air (dry stored). Each specimen was scanned at 1st day after deflasking, 14th day after deflasking, and 28th day after deflasking, and digitalized. Three dimensional deformation patterns were acquired by comparison of the data within storage group using surface matching program. For evaluating differences between groups, these data were compared statisticallyusing Kruskal Wallis and Mann Whitney-U test (α=.05). RESULTS When evaluating 3D deformation of denture base, obvious deformations were not found in maxillary and mandibular water storage group. However, in dry stored group, typical deformation pattern was detected as storage time passes. It occurred mostly in first two weeks. Major deformations were found in the bilateral posterior area in both maxillary and mandibular group. In maxillary dry stored group, a statistical significance was found. CONCLUSION It was proved that in both upper and lower denture bases, dry storage caused more dimensional deformation than water storage with typical pattern. PMID:27555899

  12. In situ electron beam irradiated rapid growth of bismuth nanoparticles in bismuth-based glass dielectrics at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Shiv Prakash; Karmakar, Basudeb, E-mail: basudebk@cgcri.res.in [Central Glass and Ceramic Research Institute (CSIR, India), Glass Science and Technology Section, Glass Division (India)

    2011-09-15

    In this study, in situ control growth of bismuth nanoparticles (Bi{sup 0} NPs) was demonstrated in bismuth-based glass dielectrics under an electron beam (EB) irradiation at room temperature. The effects of EB irradiation were investigated in situ using transmission electron microscopy (TEM), selected-area electron diffraction and high-resolution transmission electron microscopy. The EB irradiation for 2-8 min enhanced the construction of bismuth nanoparticles with a rhombohedral structure and diameter of 4-9 nm. The average particle size was found to increase with the irradiation time. Bismuth metal has a melting point of 271 Degree-Sign C and this low melting temperature makes easy the progress of energy induced structural changes during in situ TEM observations. This is a very useful technique in nano-patterning for integrated optics and other applications.

  13. Characterization of a room temperature terahertz detector based on a GaN/AlGaN HEMT

    International Nuclear Information System (INIS)

    We report on the characterization of a room temperature terahertz detector based on a GaN/AlGaN high electron mobility transistor integrated with three patch antennas. Experimental results prove that both horizontal and perpendicular electric fields are induced in the electron channel. A photocurrent is generated when the electron channel is strongly modulated by the gate voltage. Despite the large channel length and gate-source/drain distance, significant horizontal and perpendicular fields are achieved. The device is well described by the self-mixing of terahertz fields in the electron channel. The noise-equivalent power and responsivity are estimated to be 100 nW/√Hz and 3 mA=W at 292 K, respectively. No decrease in responsivity is observed up to a modulation frequency of 5 kHz. The detector performance can be further improved by engineering the source-gate-drain geometry to enhance the nonlinearity. (semiconductor devices)

  14. An analytical solution to the shielding of Co 60 teletherapy rooms based on a semiempirical equation of photon attenuation

    International Nuclear Information System (INIS)

    A semiempirical equation of polynomial-exponential type is presented to describe the transmission data of Co-60 gamma radiation in finite materials of concrete and lead. This equation and the expression obtained for the relationship of scatter-to-incident exposure made easy the developing in computer of an analytical solution for shielding calculations of Co 60 teletherapy rooms, based on the procedures of the NCRP 49 and Simpkin's method. The standard error in the estimation of parameters is less than 1.7 % except for the attenuation of 150 'o' scattered radiation in concrete that resulted in 6.3 % for one of them. The shielding calculations were compared with the data in NCRP 49 for the same conditions with a correlation better than 99 %

  15. Characterization of a room temperature terahertz detector based on a GaN/AlGaN HEMT*

    Institute of Scientific and Technical Information of China (English)

    ZhouYu; Wu Dongmin; Lou Shitao; Qin Hua; Zhang Baoshun; Sun Jiandong; Sun Yunfei; Zhang Zhipeng; Lin Wenkui; Liu Hongxin; Zeng Chunhong; Lu Min; Cai Yong

    2011-01-01

    We report on the characterization of a room temperature terahertz detector based on a GaN/AlGaN high electron mobility transistor integrated with three patch antennas. Experimental results prove that both horizontal and perpendicular electric fields are induced in the electron channel. A photocurrent is generated when the electron channel is strongly modulated by the gate voltage. Despite the large channel length and gate-source/drain distance,significant horizontal and perpendicular fields are achieved. The device is well described by the self-mixing ofterahertz fields in the electron channel. The noise-equivalent power and responsivity are estimated to be 100 nW/(√Hz) and 3 mA/W at 292 K, respectively. No decrease in responsivity is observed up to a modulation frequency of 5 kHz.The detector performance can be further improved by engineering the source-gate-drain geometry to enhance the nonlinearity.

  16. Can we recognize magmatic fluid inclusions in fossil sytems based on room-temperature phase relations and microthermometric bahavior

    Energy Technology Data Exchange (ETDEWEB)

    Bodnar, R. (Virginia Polytechnic Institute and State University, VA (USA))

    1992-08-31

    If the density and composition of magmatic fluid and how these properties vary as the system evolves are known, the room temperature phase relations and microthermometric behavior of fluid inclusions which have trapped these magmatic fluids are considered to be predictable. Using available experimental and theoretical data for the model system albite-H2O-NaCl, the salinity of the aqueous phase exsolving from melts crystallizing at various depths (pressures) in the crust were calculated. Consequently, the results of the analysis of the characteristics of fluid inclusions trapped during crystallization of a silicic melt indicated that great care should be exercised in the selection of fluid inclusions to investigate magmatic fluids. Furthermore, late hydrothermal inclusions and similar magmatic inclusions are considered to be distinguishable from one another based on mode of occurrence, presence of tiny opaque daughter phases in magmatic inclusions, and relative ages. 5 figs.

  17. A Series of Zr-Based Bulk Metallic Glasses with Room Temperature Plasticity

    Directory of Open Access Journals (Sweden)

    Anhui Cai

    2016-05-01

    Full Text Available A group of plastic Zr-Al-Ni-Cu bulk metallic glasses (BMGs with low Zr content was developed and their thermal and mechanical properties were investigated. The results show that these Zr-based BMGs have a single crystallization event for all heating rates in the studied temperature region. The glass transition temperature Tg decreases with increasing Zr content for all heating rates. There are two melting procedures for the BMGs whose Zr content is less than 52 at %, while three melting procedures for the other Zr-based BMGs. The second melting procedure is split into two melting procedures for Zr52.5Al12.2Ni12.6Cu22.7 and Zr53Al11.6Ni11.7Cu23.7 BMGs, while the first melting procedure is split into two melting procedures for the other BMGs. The activation energy decreases with increasing sensitivity index β for the studied Zr-based BMGs. The plastic strain εp is in the region of 0.2%–19.1% for these Zr-based BMGs. Both yield strength σy and fracture strength σf are smallest for Zr55Al8.9Ni7.3Cu28.8 BMG whose εp is largest among all studied Zr-based BMGs and reaches up to 19.1%. In addition, the mechanism for the large difference of the plasticity among the studied Zr-based BMGs is also discussed.

  18. Fabrication and Electrical Characterization of Multiwalled Carbon Nanotube-Based Circuit at Room Temperature

    Directory of Open Access Journals (Sweden)

    Yitian Peng

    2011-01-01

    Full Text Available Multiwalled carbon nanotube (MWCNT deposited on a pair of predetermined aluminum electrodes treated with the (3-Aminopropyl-triethoxysilane (APTES self-assembled monolayers (SAMs. The MWCNT bridges electrodes and forms electrode/MWCNT/electrode circuit on silicon with 500 nm silicon dioxide. Then the Metal (Ti/Au pads were fabricated on MWCNT to bury the MWCNT into metal electrodes. The electrical properties of MWCNT-based circuits before and after the fabrication of metal pads were characterized. Results indicate that metal pads on MWCNT improved the electrical properties MWCNT-based circuit largely.

  19. Robust Machine Learning-Based Correction on Automatic Segmentation of the Cerebellum and Brainstem.

    Directory of Open Access Journals (Sweden)

    Jun Yi Wang

    Full Text Available Automated segmentation is a useful method for studying large brain structures such as the cerebellum and brainstem. However, automated segmentation may lead to inaccuracy and/or undesirable boundary. The goal of the present study was to investigate whether SegAdapter, a machine learning-based method, is useful for automatically correcting large segmentation errors and disagreement in anatomical definition. We further assessed the robustness of the method in handling size of training set, differences in head coil usage, and amount of brain atrophy. High resolution T1-weighted images were acquired from 30 healthy controls scanned with either an 8-channel or 32-channel head coil. Ten patients, who suffered from brain atrophy because of fragile X-associated tremor/ataxia syndrome, were scanned using the 32-channel head coil. The initial segmentations of the cerebellum and brainstem were generated automatically using Freesurfer. Subsequently, Freesurfer's segmentations were both manually corrected to serve as the gold standard and automatically corrected by SegAdapter. Using only 5 scans in the training set, spatial overlap with manual segmentation in Dice coefficient improved significantly from 0.956 (for Freesurfer segmentation to 0.978 (for SegAdapter-corrected segmentation for the cerebellum and from 0.821 to 0.954 for the brainstem. Reducing the training set size to 2 scans only decreased the Dice coefficient ≤0.002 for the cerebellum and ≤ 0.005 for the brainstem compared to the use of training set size of 5 scans in corrective learning. The method was also robust in handling differences between the training set and the test set in head coil usage and the amount of brain atrophy, which reduced spatial overlap only by <0.01. These results suggest that the combination of automated segmentation and corrective learning provides a valuable method for accurate and efficient segmentation of the cerebellum and brainstem, particularly in large

  20. Investigations on spatial sound design based on measured room impulse responses

    NARCIS (Netherlands)

    Melchior, F.

    2011-01-01

    Developments in the area of spatial sound reproduction have led to a large variety of established audio systems. Systems based on stereophonic principles are extended and growing from two channels via the ITU-R BS.775 surround setup to larger systems with more channels including elevated loudspeaker

  1. Spectral correction-based method for interharmonics analysis of power signals with fundamental frequency deviation

    Energy Technology Data Exchange (ETDEWEB)

    Salor, Oezguel [TUeBiTAK - Uzay, Power Electronics Group, METU Campus, TR 06531, Ankara (Turkey)

    2009-07-15

    In this paper, a spectral correction-based algorithm for interharmonic computation is proposed for especially highly fluctuating fundamental frequency cases in the power system. It has been observed and reported that fluctuating demands of some loads such as arc furnaces, or disturbances and subsequent system transients make the fundamental frequency of the power system deviate and this causes non-existing interharmonics to appear in the spectrum due to grid-effect when a standard window length is used for the entire FFT process. The proposed method uses a synthetic waveform produced at the fundamental frequency and amplitude to determine the amount of the leakage due to the grid-effect at each frequency. Then the leakage is subtracted from the original FFT of the signal to correct the frequency spectrum. It has been shown that the leakage effect caused by the fundamental frequency variation is avoided with a correction algorithm applied after FFT and the error in the first interharmonic computation due to frequency deviation is reduced to zero exactly if the fundamental frequency can be determined accurately. Both simulative and field data tests have been performed. The method does not require online sampling frequency or FFT window length adjustment and it is simple to implement. (author)

  2. A method for multiplex gene synthesis employing error correction based on expression.

    Directory of Open Access Journals (Sweden)

    Timothy H-C Hsiau

    Full Text Available Our ability to engineer organisms with new biosynthetic pathways and genetic circuits is limited by the availability of protein characterization data and the cost of synthetic DNA. With new tools for reading and writing DNA, there are opportunities for scalable assays that more efficiently and cost effectively mine for biochemical protein characteristics. To that end, we have developed the Multiplex Library Synthesis and Expression Correction (MuLSEC method for rapid assembly, error correction, and expression characterization of many genes as a pooled library. This methodology enables gene synthesis from microarray-synthesized oligonucleotide pools with a one-pot technique, eliminating the need for robotic liquid handling. Post assembly, the gene library is subjected to an ampicillin based quality control selection, which serves as both an error correction step and a selection for proteins that are properly expressed and folded in E. coli. Next generation sequencing of post selection DNA enables quantitative analysis of gene expression characteristics. We demonstrate the feasibility of this approach by building and testing over 90 genes for empirical evidence of soluble expression. This technique reduces the problem of part characterization to multiplex oligonucleotide synthesis and deep sequencing, two technologies under extensive development with projected cost reduction.

  3. Correction factor based double model fuzzy logic control strategy of arc voltage in pulsed MIG welding

    Institute of Scientific and Technical Information of China (English)

    Wu Kaiyuan; Huang Shisheng; Meng Yongmin

    2005-01-01

    According to the feature of arc voltage control in welding steel using pulsed MIG welding, a correction factor based double model fuzzy logic controller (FLC) was developed to realize the arc voltage control by means of arc voltage feedback.When the error of peak arc voltage was great, a coarse adjusting fuzzy logic control rules with correction factor was designed,in the controller, the peak arc voltage was controlled by the wire feeding speed by means of arc voltage feedback. When the error of peak arc voltage was small, a fine adjusting fuzzy logic control rules with correction factor was designed, in this controller, the peak arc voltage was controlled by the background time by means of arc voltage feedback. The FLC was realized in a Look-Up Table ( LUT) method. Experiments had been carried out aiming at implementing the control strategy to control the arc length change in welding process. Experimental results show that the controller proposed enables the consistency of arc length and the stabolity of arc voltage and welding process to be achieved in pulsed MIG welding process.

  4. What is the benefit of CT-based attenuation correction in myocardial perfusion SPET?

    Science.gov (United States)

    Apostolopoulos, Dimitrios J; Savvopoulos, Christos

    2016-01-01

    In multimodality imaging, CT-derived transmission maps are used for attenuation correction (AC) of SPET or PET data. Regarding SPET myocardial perfusion imaging (MPI), however, the bene����t of CT-based AC (CT-AC) has been questioned. Although most attenuation-related artifacts are removed by this technique, new false defects may appear while some true perfusion abnormalities may be masked. The merits and the drawbacks of CT-AC in MPI SPET are reviewed and discussed in this editorial. In conclusion, CT-AC is most helpful in men, overweight in particular, and in those with low or low to intermediate pre-test probability of coronary artery disease (CAD). It is also useful for the evaluation of myocardial viability. In high-risk patients though, CT-AC may underestimate the presence or the extent of CAD. In any case, corrected and non-corrected images should be viewed side-by-side and both considered in the interpretation of the study.

  5. Automated model-based bias field correction of MR images of the brain.

    Science.gov (United States)

    Van Leemput, K; Maes, F; Vandermeulen, D; Suetens, P

    1999-10-01

    We propose a model-based method for fully automated bias field correction of MR brain images. The MR signal is modeled as a realization of a random process with a parametric probability distribution that is corrupted by a smooth polynomial inhomogeneity or bias field. The method we propose applies an iterative expectation-maximization (EM) strategy that interleaves pixel classification with estimation of class distribution and bias field parameters, improving the likelihood of the model parameters at each iteration. The algorithm, which can handle multichannel data and slice-by-slice constant intensity offsets, is initialized with information from a digital brain atlas about the a priori expected location of tissue classes. This allows full automation of the method without need for user interaction, yielding more objective and reproducible results. We have validated the bias correction algorithm on simulated data and we illustrate its performance on various MR images with important field inhomogeneities. We also relate the proposed algorithm to other bias correction algorithms. PMID:10628948

  6. Image-based correction of the light dilution effect for SO2 camera measurements

    Science.gov (United States)

    Campion, Robin; Delgado-Granados, Hugo; Mori, Toshiya

    2015-07-01

    Ultraviolet SO2 cameras are increasingly used in volcanology because of their ability to remotely measure the 2D distribution of SO2 in volcanic plumes, at a high frequency. However, light dilution, i.e., the scattering of ambient photons within the instrument's field of view (FoV) on air parcels located between the plume and the instrument, induces a systematic underestimation of the measurements, whose magnitude increases with distance, SO2 content, atmospheric pressure and turbidity. Here we describe a robust and straightforward method to quantify and correct this effect. We retrieve atmospheric scattering coefficients based on the contrast attenuation between the sky and the increasingly distant slope of the volcanic edifice. We illustrate our method with a case study at Etna volcano, where difference between corrected and uncorrected emission rates amounts to 40% to 80%, and investigate the temporal variations of the scattering coefficient during 1 h of measurements on Etna. We validate the correction method at Popocatépetl volcano by performing measurements of the same plume at different distances from the volcano. Finally, we reported the atmospheric scattering coefficients for several volcanoes at different latitudes and altitudes.

  7. Sensor-fingerprint based identification of images corrected for lens distortion

    Science.gov (United States)

    Goljan, Miroslav; Fridrich, Jessica

    2012-03-01

    Computational photography is quickly making its way from research labs to the market. Recently, camera manufacturers started using in-camera lens-distortion correction of the captured image to give users more powerful range of zoom in compact and affordable cameras. Since the distortion correction (barrel/pincushion) depends on the zoom, it desynchronizes the pixel-to-pixel correspondence between images taken at two different focal lengths. This poses a serious problem for digital forensic methods that utilize the concept of sensor fingerprint (photo-response non-uniformity), such as "image ballistic" techniques that can match an image to a specific camera. Such techniques may completely fail. This paper presents an extension of sensor-based camera identification to images corrected for lens distortion. To reestablish synchronization between an image and the fingerprint, we adopt a barrel distortion model and search for its parameter to maximize the detection statistic, which is the peak to correlation energy ratio. The proposed method is tested on hundreds of images from three compact cameras to prove the viability of the approach and demonstrate its efficiency.

  8. Conditions of Psychological Readiness of Pupils to Corrections in Cognitive Areas (Based on Reading

    Directory of Open Access Journals (Sweden)

    Kirakosyan A. Kh.

    2014-08-01

    Full Text Available We present a comparative study of the conditions of formation of readiness for classes in students with high and low levels of a given cognitive skill (based on the reading actions. We compared conditions associated, on the one hand, with the child's understanding that his actions are not optimal, and with the work in the zone of proximal development, on the other, with the work in the area of actual skill development and child's satisfaction of the actions result. We assumed optimality of the second type conditions for the group that needs correction. The subjects were 164 III grade student of Moscow secondary schools. The study included two types of classes and psychological readiness evaluation. The results showed that the conditions associated with the work in the area of actual development of skill and providing a positive emotional response to the child's relation to the product of their own actions, are significantly more optimal for correctional groups at a significance level of p <0,05. For a group of students with a high level of skill significant differences were not found. Thus, we showed the specificity of the conditions of readiness in the correction and describe the tasks, where the work in the area of actual development is the most optimal.

  9. Confidence intervals for a random-effects meta-analysis based on Bartlett-type corrections.

    Science.gov (United States)

    Noma, Hisashi

    2011-12-10

    In medical meta-analysis, the DerSimonian-Laird confidence interval for the average treatment effect has been widely adopted in practice. However, it is well known that its coverage probability (the probability that the interval actually includes the true value) can be substantially below the target level. One particular reason is that the validity of the confidence interval depends on the assumption that the number of synthesized studies is sufficiently large. In typical medical meta-analyses, the number of studies is fewer than 20. In this article, we developed three confidence intervals for improving coverage properties, based on (i) the Bartlett corrected likelihood ratio statistic, (ii) the efficient score statistic, and (iii) the Bartlett-type adjusted efficient score statistic. The Bartlett and Bartlett-type corrections improve the large sample approximations for the likelihood ratio and efficient score statistics. Through numerical evaluations by simulations, these confidence intervals demonstrated better coverage properties than the existing methods. In particular, with a moderate number of synthesized studies, the Bartlett and Bartlett-type corrected confidence intervals performed well. An application to a meta-analysis of the treatment for myocardial infarction with intravenous magnesium is presented.

  10. Departments of corrections as purchasers of community-based treatment: a national study.

    Science.gov (United States)

    Kubiak, Sheryl Pimlott; Arfken, Cynthia L; Gibson, Erica Shifflet

    2009-06-01

    Community-based substance abuse treatment for offenders has been shown to reduce both substance use and recidivism. One strategy to ensure treatment availability for offenders is to have each state's Department of Corrections (DOC) fund treatment directly. Purchasing treatment implies regulation, but DOC as both a purchaser and regulator of community-based services has been underexamined. This national survey of administrators from the Single State Authority (SSA) and DOC in each state found DOCs purchase treatment in 35 states, with most states purchasing it directly from community-based providers utilizing a variety of funding sources. Fewer states reported DOCs purchased ancillary services than SSAs (68% vs. 81%). Although both DOCs and SSAs had workforce and program requirements, there were differences within and between states. Most (41/42) SSA administrators reported a strong relationship with DOC. This report represents the first step in describing the availability, mechanisms, and regulations of these two publicly funded community-based treatment systems.

  11. An improved TES algorithm based on the corrected ALPHA difference spectrum

    Institute of Scientific and Technical Information of China (English)

    TANG ShiHao; LI XiaoWen; WANG JinDi; ZHU QiJiang; ZHANG LiHua

    2007-01-01

    Different from visible signals, thermal infrared radiances depend on both temperature and emissivity. It is a key problem for us to separate temperature and emissivity in thermal infrared remote sensing research. Another difficulty encountered in the retrieval of surface temperature is the correction of downwelling sky irradiance, because it is closely related to surface emissivity. When emissivity is unknown, the downwelling sky irradiance is difficult to be removed. In this paper, we introduce a correction term of downwelling sky irradiance developed by Li and Becker into Wien's approximation, to derive an improved ALPHA difference spectrum which is independent of temperature, and furthermore develop a correction term to remove the error of Wien's approximation. Under the support of the above work, attractive features of Alpha derived emissivity method and ASTER TES algorithm are combined together to acquire a new Improved TES algorithm based on Corrected ALPHA Difference Spectrum (ICADS TES). Because a multi-band inversion technique is applied, and the operations of band ratios and differences are included in the algorithm, it can partly remove the influence of atmosphere and noises. Numerical simulation experiments show that for various combinations of atmosphere, land covers and surface temperatures, the algorithm is applicable and stable. Its accuracy for temperature is 0―1.5 K, and that for emissivity is 0―0.015. Compared with current TES algorithms, our method has clear physical meaning, is easy to be implemented, and is applicable for a wide temperature range and surface types. The results are not influenced by the directional characteristic of emissivity. Because ICADS TES does not need the support of a priori information of surface types, it is also not influenced by the accuracy of classification and the problem of mixture pixels. Compared with our former TES algorithm based on corrected Alpha difference spectra (CADS TES), the new algorithm takes

  12. Development of new tip-loss corrections based on vortex theory and vortex methods

    OpenAIRE

    Branlard, Emmanuel; Gaunaa, Mac

    2012-01-01

    A new analytical formulation of the tip-loss factor is established based on helical vortex lament solutions. The derived tip-loss factor can be applied to wind-turbines, propellers or other rotary wings. Similar numerical formulations are used to assess the influence of wake expansion on tip-losses. Theodorsen's theory is successfully applied for the first time to assess the wake expansion behind a wind turbine. The tip-loss corrections obtained are compared with the ones from Prandtl and Gla...

  13. Line-based camera calibration with lens distortion correction from a single image

    Science.gov (United States)

    Zhou, Fuqiang; Cui, Yi; Gao, He; Wang, Yexin

    2013-12-01

    Camera calibration is a fundamental and important step in many machine vision applications. For some practical situations, computing camera parameters from merely a single image is becoming increasingly feasible and significant. However, the existing single view based calibration methods have various disadvantages such as ignoring lens distortion, requiring some prior knowledge or special calibration environment, and so on. To address these issues, we propose a line-based camera calibration method with lens distortion correction from a single image using three squares with unknown length. Initially, the radial distortion coefficients are obtained through a non-linear optimization process which is isolated from the pin-hole model calibration, and the detected distorted lines of all the squares are corrected simultaneously. Subsequently, the corresponding lines used for homography estimation are normalized to avoid the specific unstable case, and the intrinsic parameters are calculated from the sufficient restrictions provided by vectors of homography matrix. To evaluate the performance of the proposed method, both simulative and real experiments have been carried out and the results show that the proposed method is robust under general conditions and it achieves comparable measurement accuracy in contrast with the traditional multiple view based calibration method using 2D chessboard target.

  14. Room Temperature Ammonia Gas Sensing Using Mixed Conductor based TEMPOS Structures

    Directory of Open Access Journals (Sweden)

    Amita Chandra

    2008-10-01

    Full Text Available The current/voltage characteristics of mixed (ion+electron conductor-based ‘TEMPOS’ (Tunable Electronic Material with Pores in Oxide on Silicon structures are reported. TEMPOS are novel electronic MOS-like structures having etched swift heavy ion tracks (i.e., nanopores in the dielectric layer filled with some conducting material. The three contacts (two on top and one on the bottom, which resemble the classical bipolar or field effect transistor arrangements are, in principle, interchangeable when the overall electrical resistance along the tracks and on the surface are similar. Consequently, three configurations are obtained by interchanging the top contacts with the base contact in electronic circuits. The current/voltage characteristics show a diode like behaviour. Impedance measurements have been made for TEMPOS structures with tracks filled with ion conductors and also mixed conductors to study the ammonia sensing behaviour. The impedance has been found to be a function of frequency and magnitude of the applied signal and concentration of the ammonia solution. This is attributed to the large number of charge carriers (here protons available for conduction on exposure to ammonia and also to the large surface to volume ratio of the polymer composites embedded in the ion tracks. The measurement of both, the real and imaginary parts of impedance allows one to enhance the detection sensitivity greatly.

  15. NOvel Fission Product Separation Based on Room-Temperature Ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Hussey, Charles L.

    2005-11-13

    The effective extraction of Cs+ and Sr2+ into a relatively new and heretofore untested hydrophobic ionic liquid, tri-n-butylmethylammonium bis[(trifluoromethyl)sulfonyl]imide was demonstrated with calix[4]arene-bis(tert-octylbenzo-crown-6) and dicyclohexano-18-crown-6, respectively. The coordinated Cs+ and Sr2+ were subsequently removed from the ionic liquid extraction solvent by an electrochemical reduction process carried out at mercury electrodes. This process is non-destructive, permitting the ionic liquid and ionophores to be recycled. Although the process is based on mercury electrodes, this is a benefit rather than a detriment because the liquid mercury containing the Cs and Sr can be easily transported to another electrochemical cell where the Cs and Sr could be electrochemically recovered from the mercury amalgam and concentrated into a minimum volume of water or some other inexpensive solvent. This should facilitate the development of a suitable waste form for the extracted Cs+ and Sr2+. Thus, the feasibility of the proposed ionic liquid-based extraction cycle for the removal of 137Cs+ and 90Sr2+ from simulated aqueous tank waste was demonstrated.

  16. ARDressCode: Augmented Dressing Room with Tag-based Motion Tracking and Real-Time Clothes Simulation

    DEFF Research Database (Denmark)

    Kjærside, Krista; Kortbek, Karen Johanne; Møller, Henrik Hedegaard;

    2005-01-01

    This paper introduces a new augmented reality concept for dressing rooms enabling a customer to combine a tactile experience of the fabrics with easy simulated try-on. The dressing room has a camera and a projection surface instead of a mirror. The customers stick a few visual tags to their normal...

  17. Neural-based pile-up correction and ballistic deficit correction of X-ray semiconductor detectors using the Monte Carlo simulation and the Ramo theorem

    Science.gov (United States)

    Kafaee, Mahdi; Moussavi Zarandi, Ali; Taheri, Ali

    2016-03-01

    Pile-up distortion is a common problem in many nuclear radiation detection systems, especially in high count rates. It can be solved by hardware-based pile-up rejections, but there is no complete pile-up elimination in this way. Additionally, the methods can lead to poor quantitative results. Generally, time characteristics of semiconductor detector pulses are different from Scintillator detector pulses due to ballistic deficit. Hence, pulse processing-based pile-up correction in the detectors should consider this specification. In this paper, the artificial neural network pile-up correction method is applied for silicon detector piled-up pulses. For this purpose, the interaction of photons with a silicon detector is simulated by the MCNP4c code and the pulse current is calculated by Ramo's theorem. In this approach, we use a sub-Nyquist frequency sampling. The results show that the proposed method is reliable for pile-up correction and ballistic deficit in semiconductor detectors. The technique is remarkable for commercial considerations and high-speed, real-time calculations.

  18. FPGA-based real time controller for high order correction in EDIFISE

    Science.gov (United States)

    Rodríguez-Ramos, L. F.; Chulani, H.; Martín, Y.; Dorta, T.; Alonso, A.; Fuensalida, J. J.

    2012-07-01

    EDIFISE is a technology demonstrator instrument developed at the Institute of Astrophysics of the Canary Islands (IAC), intended to explore the feasibility of combining Adaptive Optics with attenuated optical fibers in order to obtain high spatial resolution spectra at the surroundings of a star, as an alternative to coronagraphy. A simplified version with only tip tilt correction has been tested at the OGS telescope in Observatorio del Teide (Canary islands, Spain) and a complete version is intended to be tested at the OGS and at the WHT telescope in Observatorio del Roque de los Muchachos, (Canary Islands, Spain). This paper describes the FPGA-based real time control of the High Order unit, responsible of the computation of the actuation values of a 97-actuactor deformable mirror (11x11) with the information provided by a configurable wavefront sensor of up to 16x16 subpupils at 500 Hz (128x128 pixels). The reconfigurable logic hardware will allow both zonal and modal control approaches, will full access to select which mode loops should be closed and with a number of utilities for influence matrix and open loop response measurements. The system has been designed in a modular way to allow for easy upgrade to faster frame rates (1500 Hz) and bigger wavefront sensors (240x240 pixels), accepting also several interfaces from the WFS and towards the mirror driver. The FPGA-based (Field Programmable Gate Array) real time controller provides bias and flat-fielding corrections, subpupil slopes to modal matrix computation for up to 97 modes, independent servo loop controllers for each mode with user control for independent loop opening or closing, mode to actuator matrix computation and non-common path aberration correction capability. It also provides full housekeeping control via UPD/IP for matrix reloading and full system data logging.

  19. ANN-Based Prediction and Optimization of Cooling System in Hotel Rooms

    Directory of Open Access Journals (Sweden)

    Jin Woo Moon

    2015-09-01

    Full Text Available This study aimed at developing an artificial-neural-network (ANN-based model that can calculate the required time for restoring the current indoor temperature during the setback period in accommodation buildings to the normal set-point temperature in the cooling season. By applying the calculated time in the control logic, the operation of the cooling system can be predetermined to condition the indoor temperature comfortably in a more energy-efficient manner. Three major steps employing the numerical computer simulation method were conducted for developing an ANN model and testing its prediction performance. In the development process, the initial ANN model was determined to have input neurons that had a significant statistical relationship with the output neuron. In addition, the structure of the ANN model and learning methods were optimized through the parametrical analysis of the prediction performance. Finally, through the performance tests in terms of prediction accuracy, the optimized ANN model presented a lower mean biased error (MBE rate between the simulation and prediction results under generally accepted levels. Thus, the developed ANN model was proven to have the potential to be applied to thermal control logic.

  20. Engineering of data base application to control room in operation plant

    International Nuclear Information System (INIS)

    The large number of Setpoints and associated allowable values that have to be determined in a nuclear power plant prompted EMPRESARIOS AGRUPADOS to develop the AVACO program to computerise and optimise the calculation process. This application has been developed based on Microsoft Access 97 database and Mathsoft Mathcad 8 calculation program. The calculation methodology used by AVACO complies with the procedures and criteria established in Regulatory Guide 1.105, issue 3, dated December 1999, Setpoints for Safety-Related Instrumentation, and in standard ISA-S67.04.01-2000. The computerised calculation of nominal trip points and allowable values for trip functions saves time, prevents possible errors which are more likely to occur in manual calculation, and allows adequate control of input data and results. The database contains all input data and associated references required for calculation, as well as the calculation results. This integration enables the quick and efficient handling, storage and updating of large volumes of data required for calculation. Mathcad 8 performs the calculations using templates created for different measuring channel configurations. Said templates define in text form the formulae used. Following the manual introduction of input data into the database, these data are automatically transferred to the corresponding spreadsheet template; the calculation results are then automatically incorporated back into the database. EMPRESARIOS AGRUPADOS and TECNATOM are currently using this application the Calculation of Setpoints for the Lungmen Nuclear Power Plant project

  1. A fuel cell operating between room temperature and 250 °C based on a new phosphoric acid based composite electrolyte

    Science.gov (United States)

    Lan, Rong; Xu, Xiaoxiang; Tao, Shanwen; Irvine, John T. S.

    A phosphoric acid based composite material with core-shell microstructure has been developed to be used as a new electrolyte for fuel cells. A fuel cell based on this electrolyte can operate at room temperature indicating leaching of H 3PO 4 with liquid water is insignificant at room temperature. This will help to improve the thermal cyclability of phosphoric acid based electrolyte to make it easier for practical use. The conductivity of this H 3PO 4-based electrolyte is stable at 250 °C with addition of the hydrophilic inorganic compound BPO 4 forming a core-shell microstructure which makes it possible to run a PAFC at a temperature above 200 °C. The core-shell microstructure retains after the fuel cell measurements. A power density of 350 mW/cm 2 for a H 2/O 2 fuel cell has been achieved at 200 °C. The increase in operating temperature does not have significant benefit to the performance of a H 2/O 2 fuel cell. For the first time, a composite electrolyte material for phosphoric acid fuel cells which can operate in a wide range of temperature has been evaluated but certainly further investigation is required.

  2. A novel image-based motion correction algorithm on ultrasonic image

    Science.gov (United States)

    Wang, Xuan; Li, Yaqin; Li, Shigao

    2015-12-01

    Lung respiratory movement can cause errors in the operation of image navigation surgery and they are the main errors in the navigation system. To solve this problem, the image-based motion correction strategy should be proposed to quickly correct the respiratory motion in the image sequence. So, the commercial ultrasound machine can display contrast and tissue images simultaneously. In the paper, a convenient, simple and easy-to-use breathing model whose precision was close to the sub-voxel was proposed. The first, in the clinical case the low gray-level variation in the tissue images, motion parameters were first calculated according to the actual lung movement information of each point the tissue images are registered by using template matching with sum of absolute differences metric. Finally, the similar images are selected by a double-selection method which requires global and local threshold setting. The generic breathing model was constructed based on all the sample data. The results of experiments show the algorithm can reduce the original errors caused by breath movement heavily.

  3. Vision correction for computer users based on image pre-compensation with changing pupil size.

    Science.gov (United States)

    Huang, Jian; Barreto, Armando; Alonso, Miguel; Adjouadi, Malek

    2011-01-01

    Many computer users suffer varying degrees of visual impairment, which hinder their interaction with computers. In contrast with available methods of vision correction (spectacles, contact lenses, LASIK, etc.), this paper proposes a vision correction method for computer users based on image pre-compensation. The blurring caused by visual aberration is counteracted through the pre-compensation performed on images displayed on the computer screen. The pre-compensation model used is based on the visual aberration of the user's eye, which can be measured by a wavefront analyzer. However, the aberration measured is associated with one specific pupil size. If the pupil has a different size during viewing of the pre-compensated images, the pre-compensation model should also be modified to sustain appropriate performance. In order to solve this problem, an adjustment of the wavefront function used for pre-compensation is implemented to match the viewing pupil size. The efficiency of these adjustments is evaluated with an "artificial eye" (high resolution camera). Results indicate that the adjustment used is successful and significantly improves the images perceived and recorded by the artificial eye.

  4. “Section to Point” Correction Method for Wind Power Forecasting Based on Cloud Theory

    Directory of Open Access Journals (Sweden)

    Dunnan Liu

    2015-01-01

    Full Text Available As an intermittent energy, wind power has the characteristics of randomness and uncontrollability. It is of great significance to improve the accuracy of wind power forecasting. Currently, most models for wind power forecasting are based on wind speed forecasting. However, it is stuck in a dilemma called “garbage in, garbage out,” which means it is difficult to improve the forecasting accuracy without improving the accuracy of input data such as the wind speed. In this paper, a new model based on cloud theory is proposed. It establishes a more accurate relational model between the wind power and wind speed, which has lots of catastrophe points. Then, combined with the trend during adjacent time and the laws of historical data, the forecasting value will be corrected by the theory of “section to point” correction. It significantly improves the stability of forecasting accuracy and reduces significant forecasting errors at some particular points. At last, by analyzing the data of generation power and historical wind speed in Inner Mongolia, China, it is proved that the proposed method can effectively improve the accuracy of wind speed forecasting.

  5. Amplitude spectrum compensation and phase spectrum correction of seismic data based on the generalized S transform

    Institute of Scientific and Technical Information of China (English)

    Zhou Huai-Lai; Wang Jun; Wang Ming-Chun; Shen Ming-Cheng; Zhang Xin-Kun; Liang Ping

    2014-01-01

    We propose a method for the compensation and phase correction of the ampli-tude spectrum based on the generalized S transform. The compensation of the amplitude spectrum within a reliable frequency range of the seismic record is performed in the S do-main to restore the amplitude spectrum of reflection. We use spectral simulation methods to fit the time-dependent amplitude spectrum and compensate for the amplitude attenuation owing to absorption. We use phase scanning to select the time-, space-, and frequency-dependent phases correction based on the parsimony criterion and eliminate the residual phase effect of the wavelet in the S domain. The method does not directly calculate the Q value;thus, it can be applied to the case of variable Q. The comparison of the theory model and field data verify that the proposed method can recover the amplitude spectrum of the strata reflectivity, while eliminating the effect of the residual phase of the wavelet. Thus, the wavelet approaches the zero-phase wavelet and, the seismic resolution is improved.

  6. OCR Context-Sensitive Error Correction Based on Google Web 1T 5-Gram Data Set

    CERN Document Server

    Bassil, Youssef

    2012-01-01

    Since the dawn of the computing era, information has been represented digitally so that it can be processed by electronic computers. Paper books and documents were abundant and widely being published at that time; and hence, there was a need to convert them into digital format. OCR, short for Optical Character Recognition was conceived to translate paper-based books into digital e-books. Regrettably, OCR systems are still erroneous and inaccurate as they produce misspellings in the recognized text, especially when the source document is of low printing quality. This paper proposes a post-processing OCR context-sensitive error correction method for detecting and correcting non-word and real-word OCR errors. The cornerstone of this proposed approach is the use of Google Web 1T 5-gram data set as a dictionary of words to spell-check OCR text. The Google data set incorporates a very large vocabulary and word statistics entirely reaped from the Internet, making it a reliable source to perform dictionary-based erro...

  7. An improved TES algorithm based on the corrected ALPHA difference spectrum

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Different from visible signals, thermal infrared radiances depend on both temperature and emissivity. It is a key problem for us to separate temperature and emissivity in thermal infrared remote sensing re- search. Another difficulty encountered in the retrieval of surface temperature is the correction of downwelling sky irradiance, because it is closely related to surface emissivity. When emissivity is un- known, the downwelling sky irradiance is difficult to be removed. In this paper, we introduce a correc- tion term of downwelling sky irradiance developed by Li and Becker into Wien’s approximation, to de- rive an improved ALPHA difference spectrum which is independent of temperature, and furthermore develop a correction term to remove the error of Wien’s approximation. Under the support of the above work, attractive features of Alpha derived emissivity method and ASTER TES algorithm are combined together to acquire a new Improved TES algorithm based on Corrected ALPHA Difference Spectrum (ICADS TES). Because a multi-band inversion technique is applied, and the operations of band ratios and differences are included in the algorithm, it can partly remove the influence of atmosphere and noises. Numerical simulation experiments show that for various combinations of atmosphere, land covers and surface temperatures, the algorithm is applicable and stable. Its accuracy for temperature is 0―1.5 K, and that for emissivity is 0―0.015. Compared with current TES algorithms, our method has clear physical meaning, is easy to be implemented, and is applicable for a wide temperature range and surface types. The results are not influenced by the directional characteristic of emissivity. Because ICADS TES does not need the support of a priori information of surface types, it is also not influenced by the accuracy of classification and the problem of mixture pixels. Compared with our former TES algorithm based on corrected Alpha difference spectra (CADS TES), the new

  8. Highly flexible room temperature NO2 sensor based on WO3 nanoparticles loaded MWCNTs-RGO hybrid

    Science.gov (United States)

    Yaqoob, Usman; Chung, Gwiy-Sang

    2016-02-01

    Fabrication and characterizations of a flexible NO2 sensor based on tungsten trioxide nanoparticles-loaded multi-walled carbon nanotubes-reduced graphene oxide hybrid (WO3 NPs-loaded MWCNTs-RGO) on a polyimide/polyethylene terephthalate (PI/PET) substrate have been investigated. A viscous gel of the hybrid materials (WO3-MWCNTs-RGO) was prepared with the assistance of α-terpineol. To observe the physical and crystalline properties of hybrid materials FESEM, TEM and XRD was carried-out. Afterwards, sensor was fabricated by drop casting hybrid solution between two fingers gold (Au) electrodes. Finally, gas sensing properties were taken out in open air environment. The sensor showed excellent sensing performance towards NO2 including a maximum response of 17% (to 5 ppm), a limit of detection (LOD) of 1 ppm, and relatively short response/recovery time (7/15 min). The sensing behaviors of the fabricated flexible sensor were evaluated systematically at different curvature angles (0-90°) and after several times bending and relaxing (0-107). The sensor exhibited excellent mechanical flexibility and sensing properties at room temperature without any significant performance degradation even at a curvature angle of 90° and after 106 times bending and relaxing process. The results indicates that economical, light weight and mechanical robustness of the proposed WO3 NPs-MWCNTs- RGO hybrid based sensor can be a promising building block for the development of high performance flexible NO2 sensors.

  9. Errors in MR-based attenuation correction for brain imaging with PET/MR scanners

    Science.gov (United States)

    Rota Kops, Elena; Herzog, Hans

    2013-02-01

    AimAttenuation correction of PET data acquired by hybrid MR/PET scanners remains a challenge, even if several methods for brain and whole-body measurements have been developed recently. A template-based attenuation correction for brain imaging proposed by our group is easy to handle and delivers reliable attenuation maps in a short time. However, some potential error sources are analyzed in this study. We investigated the choice of template reference head among all the available data (error A), and possible skull anomalies of the specific patient, such as discontinuities due to surgery (error B). Materials and methodsAn anatomical MR measurement and a 2-bed-position transmission scan covering the whole head and neck region were performed in eight normal subjects (4 females, 4 males). Error A: Taking alternatively one of the eight heads as reference, eight different templates were created by nonlinearly registering the images to the reference and calculating the average. Eight patients (4 females, 4 males; 4 with brain lesions, 4 w/o brain lesions) were measured in the Siemens BrainPET/MR scanner. The eight templates were used to generate the patients' attenuation maps required for reconstruction. ROI and VOI atlas-based comparisons were performed employing all the reconstructed images. Error B: CT-based attenuation maps of two volunteers were manipulated by manually inserting several skull lesions and filling a nasal cavity. The corresponding attenuation coefficients were substituted with the water's coefficient (0.096/cm). ResultsError A: The mean SUVs over the eight templates pairs for all eight patients and all VOIs did not differ significantly one from each other. Standard deviations up to 1.24% were found. Error B: After reconstruction of the volunteers' BrainPET data with the CT-based attenuation maps without and with skull anomalies, a VOI-atlas analysis was performed revealing very little influence of the skull lesions (less than 3%), while the filled nasal

  10. GLAS/ICESat L1B Global Waveform-based Range Corrections Data (HDF5) V033

    Data.gov (United States)

    National Aeronautics and Space Administration — The level 1B waveform parameterization data will contain waveform-based range corrections and surface characteristics at the full 40 per second resolution. Data...

  11. Irradiance-based emissivity correction in infrared thermography for electronic applications.

    Science.gov (United States)

    Vellvehi, M; Perpiñà, X; Lauro, G L; Perillo, F; Jordà, X

    2011-11-01

    This work analyzes, discusses, and proposes a solution to the problem of the emissivity correction present in infrared thermography when coatings with known emissivity cannot be deposited on the inspected surface. It is shown that the conventional technique based on two reference thermal images and the linearization of the blackbody radiation dependence on temperature is not a reliable and accurate solution when compared with the coating procedure. In this scenario, a new approach based on the direct processing of the output signal of the infrared camera (which is proportional to the detected irradiance) is proposed to obtain an accurate emissivity and surrounding reflections map, perfectly compensating the thermal maps. The results obtained have been validated using a module as a test vehicle containing two thermal test chips which incorporate embedded temperature sensors.

  12. Irradiance-based emissivity correction in infrared thermography for electronic applications.

    Science.gov (United States)

    Vellvehi, M; Perpiñà, X; Lauro, G L; Perillo, F; Jordà, X

    2011-11-01

    This work analyzes, discusses, and proposes a solution to the problem of the emissivity correction present in infrared thermography when coatings with known emissivity cannot be deposited on the inspected surface. It is shown that the conventional technique based on two reference thermal images and the linearization of the blackbody radiation dependence on temperature is not a reliable and accurate solution when compared with the coating procedure. In this scenario, a new approach based on the direct processing of the output signal of the infrared camera (which is proportional to the detected irradiance) is proposed to obtain an accurate emissivity and surrounding reflections map, perfectly compensating the thermal maps. The results obtained have been validated using a module as a test vehicle containing two thermal test chips which incorporate embedded temperature sensors. PMID:22128998

  13. The effect of grain refinement on the room-temperature ductility of as-cast Fe{sub 3}Al-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, S.; Andleigh, V.K.; McKamey, C.G. [Oak Ridge National Lab., TN (United States)

    1995-08-01

    Fe{sub 3}Al-based alloys exhibit poor room-temperature ductility in the as-cast condition. In this study, the effect of grain refinement of the as-cast alloy on room-temperature ductility was investigated. Small melts of Fe-28 at. % Al-5 at. % Cr were inoculated with various alloying additions and cast into a 50- x 30- x 30-mm graphite mold. The resulting ingots were examined metallographically for evidence of grain refinement, and three-point bend tests were conducted on samples to assess the effect on room-temperature ductility. Ductility was assumed to correlate with the strain corresponding to the maximum stress obtained in the bend test. The results showed that titanium was extremely effective in grain refinement, although it severely embrittled the alloy in contents exceeding 1%. Boron additions strengthened the alloy significantly, while carbon additions reduced both the strength and ductility. The best ductility was found in an alloy containing titanium, boron, and carbon. In order to verify the results of the grain refinement study, vacuum-induction melts of selected compositions were prepared and cast into a larger 25- x 150- x 100-mm graphite mold. Tensile specimens were machined from the ingots, and specimens were tested at room temperature. The results of the tensile tests agreed with the results of the grain refinement study; in addition, the addition of molybdenum was found to significantly increase room-temperature tensile ductility over that of the base alloy.

  14. Facial contour deformity correction with microvascular flaps based on the 3-dimentional template and facial moulage

    Directory of Open Access Journals (Sweden)

    Dinesh Kadam

    2013-01-01

    Full Text Available Introduction: Facial contour deformities presents with varied aetiology and degrees severity. Accurate assessment, selecting a suitable tissue and sculpturing it to fill the defect is challenging and largely subjective. Objective assessment with imaging and software is not always feasible and preparing a template is complicated. A three-dimensional (3D wax template pre-fabricated over the facial moulage aids surgeons to fulfil these tasks. Severe deformities demand a stable vascular tissue for an acceptable outcome. Materials and Methods: We present review of eight consecutive patients who underwent augmentation of facial contour defects with free flaps between June 2005 and January 2011. De-epithelialised free anterolateral thigh (ALT flap in three, radial artery forearm flap and fibula osteocutaneous flap in two each and groin flap was used in one patient. A 3D wax template was fabricated by augmenting the deformity on facial moulage. It was utilised to select the flap, to determine the exact dimensions and to sculpture intraoperatively. Ancillary procedures such as genioplasty, rhinoplasty and coloboma correction were performed. Results: The average age at the presentation was 25 years and average disease free interval was 5.5 years and all flaps survived. Mean follow-up period was 21.75 months. The correction was aesthetically acceptable and was maintained without any recurrence or atrophy. Conclusion: The 3D wax template on facial moulage is simple, inexpensive and precise objective tool. It provides accurate guide for the planning and execution of the flap reconstruction. The selection of the flap is based on the type and extent of the defect. Superiority of vascularised free tissue is well-known and the ALT flap offers a versatile option for correcting varying degrees of the deformities. Ancillary procedures improve the overall aesthetic outcomes and minor flap touch-up procedures are generally required.

  15. 3D Room Visualization on Android Based Mobile Device (with Philips™’ Surround Sound Music Player)

    OpenAIRE

    Durio Etgar; Wahyul Amien Syafei; Jack Zijlmans; Zhaorui Yuan

    2012-01-01

    This project’s specifically purposed as a demo application, so anyone can get the experience of a surround audio room without having to physically involved to it, with a main idea of generating a 3D surround sound room scenery coupled with surround sound in a handier package, namely, a “Virtual Listen Room”. Virtual Listen Room set a foundation of an innovative visualization that later will be developed and released as one of way of portable advertisement. This application was built inside of...

  16. 允差范围内变化的房间空调器测试结果算法修正%Correcting Algorithm on Experimental Results of Room Air Conditioner Performance with Dry-bulb and Wet-bulb Temperatures Changing within Allowances

    Institute of Scientific and Technical Information of China (English)

    张忠斌; 杜垲; 黄虎; 张若楠

    2014-01-01

    提出一种求解干湿球温度在国家标准允差范围内变化的制冷量和能效比实测结果向名义工况值回归逼近的修正算法,并以制冷工况下的室内侧干湿球温度允差范围变化的房间空调器制冷量和能效比测试结果为实例进行算法修正。该算法基于制冷量和能效比实测结果,采用多元高次方程逼近求解两者的回归方程,并用贝塞尔公式验证其收敛性。运用层次分析法(Analytic hierarchy process,AHP)量化分析干湿球温度对制冷量和能效比的影响程度,进而得出在干湿球温度允差范围内制冷量和能效比的修正算法。该修正算法可对任意工况下制冷量和能效比的实测值进行修正,并以此为基础对房间空调器能效等级进行评判。修正算法能更加准确地评判房间空调器能效等级,可对现行房间空调器性能测试方法进行完善。%A correcting algorithm is provided to work out regression equations to process the experimental results of cooling capacity (CC) and energy efficiency ratio (EER) of room air conditioner(RAC) when dry-bulb and wet-bulb temperatures (D&WBTs) change in the allowances set in national standard in China. Thereby, values of CC and EER under nominal working condition can be worked out. A case of the correcting algorithm is illustrated based on the experimental results of CC and EER with indoor D&WBTs changing in the allowances under space cooling condition. Based on the experimental results, the multiple high order equation is adopted to solve the regression equations of CC and EER respectively. Bessel formula is adopted to verify the convergence. The analytic hierarchy process (AHP) is adopted to present a quantitative analysis of the D&WBTs’ influence on CC and EER;thereby, the correcting equations for CC and EER with D&WBTs changing within the allowances are obtained. Within the allowances set in the national standard, these two correcting equations

  17. Anatomical-based partial volume correction for low-dose dedicated cardiac SPECT/CT

    Science.gov (United States)

    Liu, Hui; Chan, Chung; Grobshtein, Yariv; Ma, Tianyu; Liu, Yaqiang; Wang, Shi; Stacy, Mitchel R.; Sinusas, Albert J.; Liu, Chi

    2015-09-01

    Due to the limited spatial resolution, partial volume effect has been a major degrading factor on quantitative accuracy in emission tomography systems. This study aims to investigate the performance of several anatomical-based partial volume correction (PVC) methods for a dedicated cardiac SPECT/CT system (GE Discovery NM/CT 570c) with focused field-of-view over a clinically relevant range of high and low count levels for two different radiotracer distributions. These PVC methods include perturbation geometry transfer matrix (pGTM), pGTM followed by multi-target correction (MTC), pGTM with known concentration in blood pool, the former followed by MTC and our newly proposed methods, which perform the MTC method iteratively, where the mean values in all regions are estimated and updated by the MTC-corrected images each time in the iterative process. The NCAT phantom was simulated for cardiovascular imaging with 99mTc-tetrofosmin, a myocardial perfusion agent, and 99mTc-red blood cell (RBC), a pure intravascular imaging agent. Images were acquired at six different count levels to investigate the performance of PVC methods in both high and low count levels for low-dose applications. We performed two large animal in vivo cardiac imaging experiments following injection of 99mTc-RBC for evaluation of intramyocardial blood volume (IMBV). The simulation results showed our proposed iterative methods provide superior performance than other existing PVC methods in terms of image quality, quantitative accuracy, and reproducibility (standard deviation), particularly for low-count data. The iterative approaches are robust for both 99mTc-tetrofosmin perfusion imaging and 99mTc-RBC imaging of IMBV and blood pool activity even at low count levels. The animal study results indicated the effectiveness of PVC to correct the overestimation of IMBV due to blood pool contamination. In conclusion, the iterative PVC methods can achieve more accurate quantification, particularly for low

  18. Adaptive scene-based nonuniformity correction method for infrared-focal plane arrays

    Science.gov (United States)

    Torres, Sergio N.; Vera, Esteban M.; Reeves, Rodrigo A.; Sobarzo, Sergio K.

    2003-08-01

    The non-uniform response in infrared focal plane array (IRFPA) detectors produces corrupted images with a fixed-pattern noise. In this paper we present an enhanced adaptive scene-based non-uniformity correction (NUC) technique. The method simultaneously estimates detector's parameters and performs the non-uniformity compensation using a neural network approach. In addition, the proposed method doesn't make any assumption on the kind or amount of non-uniformity presented on the raw data. The strength and robustness of the proposed method relies in avoiding the presence of ghosting artifacts through the use of optimization techniques in the parameter estimation learning process, such as: momentum, regularization, and adaptive learning rate. The proposed method has been tested with video sequences of simulated and real infrared data taken with an InSb IRFPA, reaching high correction levels, reducing the fixed pattern noise, decreasing the ghosting, and obtaining an effective frame by frame adaptive estimation of each detector's gain and offset.

  19. An Improved Scene-based Nonuniformity Correction Algorithm for Infrared Focal Plane Arrays Using Neural Networks

    Institute of Scientific and Technical Information of China (English)

    SUI Jing; JIN Wei-qi; DONG Li-quan; WANG Xia; GUO Hong

    2006-01-01

    The improved scene-based adaptive nonuniformity correction (NUC) algorithms using a neural network (NNT) approach for infrared image sequences are presented and analyzed. The retina-like neural networks using steepest descent model was the first proposed infrared focal plane arrays (IRFPA) nonuniformity compensation method, which can perform parameter estimation of the sensors over time on a frame by frame basis. To increase the strength and the robustness of the NNT algorithm and to avoid the presence of ghosting artifacts, some optimization techniques, including momentum term,regularization factor and adaptive learning rate, were executed in the parameter learning process. In this paper, the local median filtering result of Xij ( n ) is proposed as an alternative value of desired network output of neuron Xij ( n ), denoted as Tij ( n ), which is the local spatial average of Xij ( n ) in traditional NNT methods. Noticeably, the NUC algorithm is inter-frame adaptive in nature and does not rely on any statistical assumptions on the scene data in the image sequence.Applications of this algorithm to the simulated video sequences and real infrared data taken with PV320 show that the correction results of image sequence are better than that of using original NNT approach, especially for the short-time image sequences (several hundred frames) subjected to the dense impulse noises with a number of dead or saturated pixels.

  20. Predictor-based error correction method in short-term climate prediction

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In terms of the basic idea of combining dynamical and statistical methods in short-term climate prediction, a new prediction method of predictor-based error correction (PREC) is put forward in order to effectively use statistical experiences in dynamical prediction. Analyses show that the PREC can reasonably utilize the significant correlations between predictors and model prediction errors and correct prediction errors by establishing statistical prediction model. Besides, the PREC is further applied to the cross-validation experiments of dynamical seasonal prediction on the operational atmosphere-ocean coupled general circulation model of China Meteorological Administration/National Climate Center by selecting the sea surface temperature index in Ni(n)o3 region as the physical predictor that represents the prevailing ENSO-cycle mode of interannual variability in climate system. It is shown from the prediction results of summer mean circulation and total precipitation that the PREC can improve predictive skills to some extent. Thus the PREC provides a new approach for improving short-term climate prediction.

  1. Dynamic Aberration Correction for Conformal Window of High-Speed Aircraft Using Optimized Model-Based Wavefront Sensorless Adaptive Optics

    Science.gov (United States)

    Dong, Bing; Li, Yan; Han, Xin-li; Hu, Bin

    2016-01-01

    For high-speed aircraft, a conformal window is used to optimize the aerodynamic performance. However, the local shape of the conformal window leads to large amounts of dynamic aberrations varying with look angle. In this paper, deformable mirror (DM) and model-based wavefront sensorless adaptive optics (WSLAO) are used for dynamic aberration correction of an infrared remote sensor equipped with a conformal window and scanning mirror. In model-based WSLAO, aberration is captured using Lukosz mode, and we use the low spatial frequency content of the image spectral density as the metric function. Simulations show that aberrations induced by the conformal window are dominated by some low-order Lukosz modes. To optimize the dynamic correction, we can only correct dominant Lukosz modes and the image size can be minimized to reduce the time required to compute the metric function. In our experiment, a 37-channel DM is used to mimic the dynamic aberration of conformal window with scanning rate of 10 degrees per second. A 52-channel DM is used for correction. For a 128 × 128 image, the mean value of image sharpness during dynamic correction is 1.436 × 10−5 in optimized correction and is 1.427 × 10−5 in un-optimized correction. We also demonstrated that model-based WSLAO can achieve convergence two times faster than traditional stochastic parallel gradient descent (SPGD) method. PMID:27598161

  2. Dynamic Aberration Correction for Conformal Window of High-Speed Aircraft Using Optimized Model-Based Wavefront Sensorless Adaptive Optics.

    Science.gov (United States)

    Dong, Bing; Li, Yan; Han, Xin-Li; Hu, Bin

    2016-09-02

    For high-speed aircraft, a conformal window is used to optimize the aerodynamic performance. However, the local shape of the conformal window leads to large amounts of dynamic aberrations varying with look angle. In this paper, deformable mirror (DM) and model-based wavefront sensorless adaptive optics (WSLAO) are used for dynamic aberration correction of an infrared remote sensor equipped with a conformal window and scanning mirror. In model-based WSLAO, aberration is captured using Lukosz mode, and we use the low spatial frequency content of the image spectral density as the metric function. Simulations show that aberrations induced by the conformal window are dominated by some low-order Lukosz modes. To optimize the dynamic correction, we can only correct dominant Lukosz modes and the image size can be minimized to reduce the time required to compute the metric function. In our experiment, a 37-channel DM is used to mimic the dynamic aberration of conformal window with scanning rate of 10 degrees per second. A 52-channel DM is used for correction. For a 128 × 128 image, the mean value of image sharpness during dynamic correction is 1.436 × 10(-5) in optimized correction and is 1.427 × 10(-5) in un-optimized correction. We also demonstrated that model-based WSLAO can achieve convergence two times faster than traditional stochastic parallel gradient descent (SPGD) method.

  3. Development of a practical image-based scatter correction method for brain perfusion SPECT: comparison with the TEW method

    Energy Technology Data Exchange (ETDEWEB)

    Shidahara, Miho; Kato, Takashi; Kawatsu, Shoji; Yoshimura, Kumiko; Ito, Kengo [National Center for Geriatrics and Gerontology Research Institute, Department of Brain Science and Molecular Imaging, Obu, Aichi (Japan); Watabe, Hiroshi; Kim, Kyeong Min; Iida, Hidehiro [National Cardiovascular Center Research Institute, Department of Investigative Radiology, Suita (Japan); Kato, Rikio [National Center for Geriatrics and Gerontology, Department of Radiology, Obu (Japan)

    2005-10-01

    An image-based scatter correction (IBSC) method was developed to convert scatter-uncorrected into scatter-corrected SPECT images. The purpose of this study was to validate this method by means of phantom simulations and human studies with {sup 99m}Tc-labeled tracers, based on comparison with the conventional triple energy window (TEW) method. The IBSC method corrects scatter on the reconstructed image I{sub AC}{sup {mu}}{sup b} with Chang's attenuation correction factor. The scatter component image is estimated by convolving I{sub AC}{sup {mu}}{sup b} with a scatter function followed by multiplication with an image-based scatter fraction function. The IBSC method was evaluated with Monte Carlo simulations and {sup 99m}Tc-ethyl cysteinate dimer SPECT human brain perfusion studies obtained from five volunteers. The image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were compared. Using data obtained from the simulations, the image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were found to be nearly identical for both gray and white matter. In human brain images, no significant differences in image contrast were observed between the IBSC and TEW methods. The IBSC method is a simple scatter correction technique feasible for use in clinical routine. (orig.)

  4. MR-based attenuation correction for cardiac FDG PET on a hybrid PET/MRI scanner: comparison with standard CT attenuation correction

    Energy Technology Data Exchange (ETDEWEB)

    Vontobel, Jan; Liga, Riccardo; Possner, Mathias; Clerc, Olivier F.; Mikulicic, Fran; Veit-Haibach, Patrick; Voert, Edwin E.G.W. ter; Fuchs, Tobias A.; Stehli, Julia; Pazhenkottil, Aju P.; Benz, Dominik C.; Graeni, Christoph; Gaemperli, Oliver; Herzog, Bernhard; Buechel, Ronny R.; Kaufmann, Philipp A. [University Hospital Zurich, Department of Nuclear Medicine, Zurich (Switzerland)

    2015-09-15

    The aim of this study was to evaluate the feasibility of attenuation correction (AC) for cardiac {sup 18}F-labelled fluorodeoxyglucose (FDG) positron emission tomography (PET) using MR-based attenuation maps. We included 23 patients with no known cardiac history undergoing whole-body FDG PET/CT imaging for oncological indications on a PET/CT scanner using time-of-flight (TOF) and subsequent whole-body PET/MR imaging on an investigational hybrid PET/MRI scanner. Data sets from PET/MRI (with and without TOF) were reconstructed using MR AC and semi-quantitative segmental (20-segment model) myocardial tracer uptake (per cent of maximum) and compared to PET/CT which was reconstructed using CT AC and served as standard of reference. Excellent correlations were found for regional uptake values between PET/CT and PET/MRI with TOF (n = 460 segments in 23 patients; r = 0.913; p < 0.0001) with narrow Bland-Altman limits of agreement (-8.5 to +12.6 %). Correlation coefficients were slightly lower between PET/CT and PET/MRI without TOF (n = 460 segments in 23 patients; r = 0.851; p < 0.0001) with broader Bland-Altman limits of agreement (-12.5 to +15.0 %). PET/MRI with and without TOF showed minimal underestimation of tracer uptake (-2.08 and -1.29 %, respectively), compared to PET/CT. Relative myocardial FDG uptake obtained from MR-based attenuation corrected FDG PET is highly comparable to standard CT-based attenuation corrected FDG PET, suggesting interchangeability of both AC techniques. (orig.)

  5. Life Expectancy at Birth in Rural Areas Based on Corrected Data of the Iranian Vital Horoscope

    Directory of Open Access Journals (Sweden)

    A Khosravi

    2012-09-01

    Full Text Available Background: Life expectancy at birth as an alternative summary measure of mortality represents number of years which a newborn will be alive based on the current age specific death rates. As it summarizes death rates across all age range in a given population is the most common summary measure of mortality. The aim of this study was to correct death rates for underreport and estimate life expectancy at birth in rural population of Iran in 2008. In addition, this study aimed to assess the Vital Horoscope system's data quality. Methods: Data were obtained from all Health Houses in Iranian villages in 2008. In order to adjust over 5 years old death rates for underreport, we used Brass Growth Balance method. Since this method is not applicable to under 5 years old, we used child mortality rates projected based on the Iranian Demographic and Health survey 2000 to correct death rates. Results: Adjusted life expectancy at birth for males was 71.5 year and for females was 74.4 year. Completeness of the death data was 88% for males and 79% for females. Adjusted child (under 5 mortality rate by sex in males and females was 25.9 and 23.8 per 1000 live births respectively. Adult mortality for males was 167.2 and 98.3 for females per 1000. Conclusion: Data based on Vital Horoscope system are a suitable source to estimate life expectancy and other mortality statistics. Also has an acceptable completeness on death registration. Further studies to investigate accuracy of data from the Vital Horoscope system are suggested.

  6. Correcting Positional Errors in Shore-Based Theodolite Measurements of Animals at Sea

    Directory of Open Access Journals (Sweden)

    Ophélie Sagnol

    2014-01-01

    Full Text Available Determining the position of animals at sea can be particularly difficult and yet, accurate range and position of animals at sea are essential to answer a wide range of biological questions. Shore-based theodolite techniques have been used in a number of studies to examine marine mammal movement patterns and habitat use, offering reliable position measurements. In this study we explored the accuracy of theodolite measurements by comparing positional information of the same objects using two independent techniques: a shore-based theodolite station and an onboard GPS over a range of 25 km from the shore-based station. The technique was developed to study the habitat use of sperm whales (Physeter macrocephalus off Kaikoura, New Zealand. We observed that the position accuracy fell rapidly with an increase in range from the shore-based station. Results showed that the horizontal angle was accurately determined, but this was not the case for the vertical angle. We calibrated the position of objects at sea with a regression-based correction to fit the difference in distance between simultaneously recorded theodolite fixes and GPS positions. This approach revealed the necessity to calibrate theodolite measurements with objects at sea of known position.

  7. Room temperature analysis of dielectric function of ZnO-based thin film on fused quartz substrate

    Science.gov (United States)

    Kurniawan, Robi; Sutjahja, Inge M.; Winata, Toto; Rusydi, Andrivo; Darma, Yudi

    2015-09-01

    A set of sample consist of pure ZnO and Cu-doped ZnO film were grown on fused-quartz substrates using pulsed laser deposition (PLD) technique. Here, we report room temperature spectroscopic ellipsometry analysis (covering energy range of 0.5 to 6.3 eV) of pure ZnO film and Cu doped ZnO film at 8 in at. %. The thickness of pure ZnO and Cu-doped ZnO film using in this study is about 350 nm. To extract the dielectric function of ZnO thin film, multilayer modeling is performed which takes into account reflections at each interface through Fresnel coefficients. This method based on Drude-Lorentz models that connect with Kramers-Kronig relations. The best fitting of Ψ (amplitude ratio) and Δ (phase difference) taken by SE measurement are obtained reasonably well by mean the universal fitting of three different photon incident angles. The imaginary part of dielectric function (ɛ2) show the broad peak at around 3.3 eV assigned as combination of optical band energy edge with excitonic states. The exitonic states could not be observed clearly in this stage. The evolution of extracted dielectric function is observable by introducing 8% Cu as indicated by decreasing of excitonic intensity. This result indicates the screening of excitonic state. This study will bring us to have a good undestanding for the role of Cu impurities for ZnO thin films.

  8. Electrochemical gas sensors based on paper-supported room-temperature ionic liquids for improved analysis of acid vapours.

    Science.gov (United States)

    Toniolo, Rosanna; Dossi, Nicolò; Pizzariello, Andrea; Casagrande, Alice; Bontempelli, Gino

    2013-04-01

    A prototype of a fast-response task-specific amperometric gas sensor based on paper-supported room-temperature ionic liquids (RTILs) is proposed here for improved analysis of volatile acid species. It consists of a small filter paper foil soaked with a RTIL mixture containing an ionic liquid whose anion (acetate) displays a basic character, upon which three electrodes are screen printed by carbon ink profiting from a suitable mask. It takes advantage of the high electrical conductivity and negligible vapour pressure of RTILs and of their easy immobilization into a porous and inexpensive supporting material such as paper. The performance of this device, used as a wall-jet amperometric detector for flow injection analyses of headspace samples in equilibrium with aqueous solutions at controlled concentrations, was evaluated for phenol and 1-butanethiol vapours which were adopted as model acid gaseous analytes. The results obtained showed that the quite high potentials required for the detection of these analytes are lowered significantly, thanks to the addition of the basic acetate RTIL. In such a way, overlap with the medium discharge is avoided, and the possible adverse effect of interfering species is minimised. The sensor performance was quite satisfactory (detection limits, ca. 0.3 μM; dynamic range, ca. 1-200 μM, both referred to solution concentrations; correlation coefficients in the range 0.993-0.997; repeatability, ± 6% RSD; long-term stability, 9%); thus suggesting the possible use of this device for manifold applications.

  9. A fuzzy-theory-based behavioral model for studying pedestrian evacuation from a single-exit room

    Science.gov (United States)

    Fu, Libi; Song, Weiguo; Lo, Siuming

    2016-08-01

    Many mass events in recent years have highlighted the importance of research on pedestrian evacuation dynamics. A number of models have been developed to analyze crowd behavior under evacuation situations. However, few focus on pedestrians' decision-making with respect to uncertainty, vagueness and imprecision. In this paper, a discrete evacuation model defined on the cellular space is proposed according to the fuzzy theory which is able to describe imprecise and subjective information. Pedestrians' percept information and various characteristics are regarded as fuzzy input. Then fuzzy inference systems with rule bases, which resemble human reasoning, are established to obtain fuzzy output that decides pedestrians' movement direction. This model is tested in two scenarios, namely in a single-exit room with and without obstacles. Simulation results reproduce some classic dynamics phenomena discovered in real building evacuation situations, and are consistent with those in other models and experiments. It is hoped that this study will enrich movement rules and approaches in traditional cellular automaton models for evacuation dynamics.

  10. Gallium-Based Room Temperature Liquid Metals and its Application to Single Channel Two-Liquid Hyperelastic Capacitive Strain Sensors

    Science.gov (United States)

    Liu, Shanliangzi

    Gallium-based liquid metals are of interest for a variety of applications including flexible electronics, soft robotics, and biomedical devices. Still, nano- to microscale device fabrication with these materials is challenging because of their strong adhesion to a majority of substrates. This unusual high adhesion is attributed to the formation of a thin oxide shell; however, its role in the adhesion process has not yet been established. In the first part of the thesis, we described a multiscale study aiming at understanding the fundamental mechanisms governing wetting and adhesion of gallium-based liquid metals. In particular, macroscale dynamic contact angle measurements were coupled with Scanning Electron Microscope (SEM) imaging to relate macroscopic drop adhesion to morphology of the liquid metal-surface interface. In addition, room temperature liquid-metal microfluidic devices are also attractive systems for hyperelastic strain sensing. Currently two types of liquid metal-based strain sensors exist for inplane measurements: single-microchannel resistive and two-microchannel capacitive devices. However, with a winding serpentine channel geometry, these sensors typically have a footprint of about a square centimeter, limiting the number of sensors that can be embedded into. In the second part of the thesis, firstly, simulations and an experimental setup consisting of two GaInSn filled tubes submerged within a dielectric liquid bath are used to quantify the effects of the cylindrical electrode geometry including diameter, spacing, and meniscus shape as well as dielectric constant of the insulating liquid and the presence of tubing on the overall system's capacitance. Furthermore, a procedure for fabricating the two-liquid capacitor within a single straight polydiemethylsiloxane channel is developed. Lastly, capacitance and response of this compact device to strain and operational issues arising from complex hydrodynamics near liquid-liquid and liquid

  11. A three-dimensional model-based partial volume correction strategy for gated cardiac mouse PET imaging

    Science.gov (United States)

    Dumouchel, Tyler; Thorn, Stephanie; Kordos, Myra; DaSilva, Jean; Beanlands, Rob S. B.; deKemp, Robert A.

    2012-07-01

    Quantification in cardiac mouse positron emission tomography (PET) imaging is limited by the imaging spatial resolution. Spillover of left ventricle (LV) myocardial activity into adjacent organs results in partial volume (PV) losses leading to underestimation of myocardial activity. A PV correction method was developed to restore accuracy of the activity distribution for FDG mouse imaging. The PV correction model was based on convolving an LV image estimate with a 3D point spread function. The LV model was described regionally by a five-parameter profile including myocardial, background and blood activities which were separated into three compartments by the endocardial radius and myocardium wall thickness. The PV correction was tested with digital simulations and a physical 3D mouse LV phantom. In vivo cardiac FDG mouse PET imaging was also performed. Following imaging, the mice were sacrificed and the tracer biodistribution in the LV and liver tissue was measured using a gamma-counter. The PV correction algorithm improved recovery from 50% to within 5% of the truth for the simulated and measured phantom data and image uniformity by 5-13%. The PV correction algorithm improved the mean myocardial LV recovery from 0.56 (0.54) to 1.13 (1.10) without (with) scatter and attenuation corrections. The mean image uniformity was improved from 26% (26%) to 17% (16%) without (with) scatter and attenuation corrections applied. Scatter and attenuation corrections were not observed to significantly impact PV-corrected myocardial recovery or image uniformity. Image-based PV correction algorithm can increase the accuracy of PET image activity and improve the uniformity of the activity distribution in normal mice. The algorithm may be applied using different tracers, in transgenic models that affect myocardial uptake, or in different species provided there is sufficient image quality and similar contrast between the myocardium and surrounding structures.

  12. Supported La2O3 and MgO nanoparticles as solid base catalysts for aldol reaction while suppressing dehydration at room temperaure

    NARCIS (Netherlands)

    Frey, A.M.; Kumar Karmee, S.; Jong, de K.P.; Bitter, J.H.; Hanefeld, U.

    2013-01-01

    La2O3 and MgO nanoparticles (3–4 nm) supported on carbon nanofibers were evaluated as solid base catalysts for the aldol reaction of benzaldehyde and acetone at room temperature. Both catalysts were found to be highly active and selective with respect to 4-hydroxy-4-phenylbutan-2-one, thus suppressi

  13. Streaming Media over a Color Overlay Based on Forward Error Correction Technique

    Institute of Scientific and Technical Information of China (English)

    张晓瑜; 沈国斌; 李世鹏; 钟玉琢

    2004-01-01

    The number of clients that receive high-quality streaming video from a source is greatly limited by the application requirements,such as the high bandwidth and reliability.In this work,a method was developed to construct a color overlay,which enables clients to receive data across multiple paths,based on the forward error correction technique.The color overlay enlarges system capacity by reducing the bottlenecks and extending the bandwidth,improves reliability against node failure,and is more resilient to fluctuations of network metrics.A light-weight protocol for building the overlay is also presented.Extensive simulations were conducted and the results clearly support the claimed advantages.

  14. Early warning system for coffee rust disease based on error correcting output codes: a proposal

    Directory of Open Access Journals (Sweden)

    David Camilo Corrales

    2014-12-01

    Full Text Available Colombian coffee producers have had to face the severe consequences of the coffee rust disease since it was first reported in the country in 1983. Recently, machine learning researchers have tried to predict infection through classifiers such as decision trees, regression Support Vector Machines (SVM, non-deterministic classifiers and Bayesian Networks, but it has been theoretically and empirically demonstrated that combining multiple classifiers can substantially improve the classification performance of the constituent members. An Early Warning System (EWS for coffee rust disease was therefore proposed based on Error Correcting Output Codes (ECOC and SVM to compute the binary functions of Plant Density, Shadow Level, Soil Acidity, Last Nighttime Rainfall Intensity and Last Days Relative Humidity.

  15. Vorticity-based correction for modelling of free-surface wave interacting with turbulent current

    Science.gov (United States)

    Zhang, Wei

    2014-11-01

    This paper describes a new vorticity-based correction model for studying the interaction between free-surface wave and turbulent current. To track free-surface movements, the volume of fluid (VOF) method is employed. The momentum equations are rewritten to avoid the numerically generated vorticity effects along the air-water interface. Simultaneously unsteady RANS equations are used, while standard k-epsilon model is adapted with modification to the production term by introducing the vorticity to limit the production of turbulent kinematic energy at free surface. To validate the numerical model used here, standalone wave and current cases are studied to ensure the accuracy of each component of the numerical model. The model is then used to simulate the interaction between the second-order stokes wave and turbulent current for both wave following and countering in a setting of shallow water wave flume. The results are compared with experimental measurement available in the literature.

  16. Method and simulation for spacecraft clock correction based on x-ray pulsars signal

    Science.gov (United States)

    Gui, Xianzhou; Sun, Chen; Huang, Senlin

    2015-07-01

    X-ray pulsar-based spacecraft navigation comes to be a new kind of autonomous navigation technology with high potential, for the advantages of high reliability, good autonomy, high precision and wide applicability. Timing, determination of position and attitude are main prospects of using X-ray pulsars [1,2]. To realize the pulse signal timing, in this paper, a Phase-Locked Loop circuit for tracking pulsar signal frequency is designed; PLL is built in the Simulink environment and tested by using simple pulse signal to get circuit parameters with good track effect. The Crab Nebula pulse profile, which is used as the simulation signal source, is modelled by using the mathematical method [3]. The simulation results show that the PLL circuit designed in the paper can track the frequency of pulse signal precisely and can be used for spacecraft clock correction.

  17. Fundamental building blocks for molecular biowire based forward error-correcting biosensors

    Science.gov (United States)

    Liu, Yang; Chakrabartty, Shantanu; Alocilja, Evangelyn C.

    2007-10-01

    This paper describes the fabrication, characterization and modeling of fundamental logic gates that can be used for designing biosensors with embedded forward error-correction (FEC). The proposed logic gates (AND and OR) are constructed by patterning antibodies at different spatial locations along the substrate of a lateral flow immunosensor assay. The logic gates operate by converting binding events between an antigen and an antibody into a measurable electrical signal using polyaniline nanowires as the transducer. In this study, B. cereus and E. coli have been chosen as model pathogens. The functionality of the AND and OR logic gates has been validated using conductance measurements with different pathogen concentrations. Experimental results show that the change in conductance across the gates can be modeled as a log-linear response with respect to varying pathogen concentration. Equivalent circuits models for AND and OR logic gates have been derived based on measured results.

  18. A LQP BASED INTERIOR PREDICTION-CORRECTION METHOD FOR NONLINEAR COMPLEMENTARITY PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    Bing-sheng He; Li-zhi Liao; Xiao-ming Yuan

    2006-01-01

    To solve nonlinear complementarity problems (NCP), at each iteration, the classical proximal point algorithm solves a well-conditioned sub-NCP while the LogarithmicQuadratic Proximal (LQP) method solves a system of nonlinear equations (LQP system). This paper presents a practical LQP method-based prediction-correction method for NCP.The predictor is obtained via solving the LQP system approximately under significantly relaxed restriction, and the new iterate (the corrector) is computed directly by an explicit formula derived from the original LQP method. The implementations are very easy to be carried out. Global convergence of the method is proved under the same mild assumptions as the original LQP method. Finally, numerical results for traffic equilibrium problems are provided to verify that the method is effective for some practical problems.

  19. Computational optical distortion correction using a radial basis function-based mapping method.

    Science.gov (United States)

    Bauer, Aaron; Vo, Sophie; Parkins, Keith; Rodriguez, Francisco; Cakmakci, Ozan; Rolland, Jannick P

    2012-07-01

    A distortion mapping and computational image unwarping method based on a network interpolation that uses radial basis functions is presented. The method is applied to correct distortion in an off-axis head-worn display (HWD) presenting up to 23% highly asymmetric distortion over a 27°x21° field of view. A 10(-5) mm absolute error of the mapping function over the field of view was achieved. The unwarping efficacy was assessed using the image-rendering feature of optical design software. Correlation coefficients between unwarped images seen through the HWD and the original images, as well as edge superimposition results, are presented. In an experiment, images are prewarped using radial basis functions for a recently built, off-axis HWD with a 20° diagonal field of view in a 4:3 ratio. Real-time video is generated by a custom application with 2 ms added latency and is demonstrated.

  20. Target mass correction, based on the re-scaled parton densities

    CERN Document Server

    Yazdanpanah, M M; Mirjalili, A

    2014-01-01

    Target mass correction (TMC) is being used to improve the theoretical results for the nucleon structure functions. This improvement makes the fitting more reliable with the available experimental data in lepton scattering off the nucleon . The recent relations, using the Georgi and Politzer approach indicate that employing TMC effect are cumbersome, long and contains complicated integrals. Some of these integrals can not be solved exactly and people are forced to use approximate methods which seems not to give sufficient and precise results. On the other hand on analysing the TMC effect we encounter with the threshold problem for nucleon structure which results to have the structure function in a regions which are physically forbidden. Here we render a new solution way, based on the re-scaled parton densities to resolve the difficultly, relating to the TMC effect. Our solution way can be employed directly and easily to the parton distribution rather than to the nucleon structure function. There are different ...

  1. Guidelines for control room design reviews

    International Nuclear Information System (INIS)

    The control room design review is part of a broad program being undertaken by the nuclear industry and the government to ensure consideration of human factors in nuclear power plant design and operation. The purpose of the control room design review described by these guidelines is to (1) review and evaluate the control room workspace, instrumentation, controls, and other equipment from a human factors engineering point of view that takes into account both system demands and operator capabilities; and (2) to identify, assess, and implement control room design modifications that correct inadequate or unsuitable items. The scope of the control room design review described by these guidelines covers the human engineering review of completed control rooms; i.e., operational control rooms or those at that stage of the licensing process where control room design and equipment selection are committed. These guidelines should also be of use during the design process for new control rooms. However, additional analyses to optimize the allocation of functions to man and machine, and further examination of advanced control system technology, are recommended for new control rooms. Guidelines and references for comprehensive system analyses designed to incorporate human factors considerations into the design and development of new control rooms are presented in Appendix B. Where possible, a generic approach to the control room design review process is encouraged; for example, when control room designs are replicated wholly or in part in two or more units. Even when designs are not replicated exactly, generic reviews which can be modified to account for specific differences in particular control rooms should be considered. Industry organizations and owners groups are encouraged to coordinate joint efforts and share data to develop generic approaches to the design review process. The control room design review should accomplish the following specific objectives. To determine

  2. Model-based correction algorithms improving the accuracy of hydrostatic level measurement on pressure vessels

    International Nuclear Information System (INIS)

    It is important to possess precise process information for an optimised valuation of the plant process conditions. Especially these information have a great priority as well as for the emergency operation and post accident management. The rapid and great transitions resulting from that are hardly to master by the used measuring devices. Spurious indications can occur the cause of which could be a modification of design conditions, specific transients of process and the damage of the measuring instrument itself respectively during accidents. Further more it would be desirable to get additional not measurable state variables in this situation. For solving those problems modern methods and procedures of process identification, parameter identification and plausibility analysis comprising correction algorithms become more and more important. These modern methods are used to solve the following problems - diagnosis of the process state on the basis of combination by measuring variables, analytical redundancy and linguistic declarations, - reconstruction of not directly measurable variables and parameters respectively - detection and identification of process faults and instrumentation faults (diagnosis) - reconfiguration of measuring signals (correction). The reconstruction of process state is thus a combination of measured quantity, reconstructed state variables and analytical redundancy using model-based measuring methods. The use of model based measuring methods has been investigated on the example of hydrostatic level measurement on horizontal steam generators. The results of experiments on pilot plants as well as comparison with calculations of empowered programs for instants ATHLET and methods of parameter identification serve as a verification of methods and algorithms, which were developed. This paper describe the main facts of this work

  3. Stochastic bias correction of dynamically downscaled precipitation fields for Germany through Copula-based integration of gridded observation data

    Directory of Open Access Journals (Sweden)

    G. Mao

    2015-04-01

    Full Text Available Dynamically downscaled precipitation fields from regional climate models (RCMs often cannot be used directly for regional climate studies. Due to their inherent biases, i.e., systematic over- or underestimations compared to observations, several correction approaches have been developed. Most of the bias correction procedures such as the quantile mapping approach employ a transfer function that is based on the statistical differences between RCM output and observations. Apart from such transfer function-based statistical correction algorithms, a stochastic bias correction technique, based on the concept of Copula theory, is developed here and applied to correct precipitation fields from the Weather Research and Forecasting (WRF model. For dynamically downscaled precipitation fields we used high-resolution (7 km, daily WRF simulations for Germany driven by ERA40 reanalysis data for 1971–2000. The REGNIE (REGionalisierung der NIEderschlagshöhen data set from the German Weather Service (DWD is used as gridded observation data (1 km, daily and aggregated to 7 km for this application. The 30-year time series are split into a calibration (1971–1985 and validation (1986–2000 period of equal length. Based on the estimated dependence structure (described by the Copula function between WRF and REGNIE data and the identified respective marginal distributions in the calibration period, separately analyzed for the different seasons, conditional distribution functions are derived for each time step in the validation period. This finally allows to get additional information about the range of the statistically possible bias-corrected values. The results show that the Copula-based approach efficiently corrects most of the errors in WRF derived precipitation for all seasons. It is also found that the Copula-based correction performs better for wet bias correction than for dry bias correction. In autumn and winter, the correction introduced a small dry

  4. Effects of aging in high temperature helium environments on room temperature tensile properties of nickel-base superalloys

    International Nuclear Information System (INIS)

    Research highlights: → Haynes 230 is susceptible to carburization, but Alloy 617 to decarburization and inter-granular oxidation. → Decarburization of Nickel-base superalloys can be accelerated in impure helium with H2. → Aging heat treatment causes inter-granular fracture primarily along inter-granular oxide and grain boundary carbides, which results in the loss of ductility. → Thin-plate specimen of Alloy 617 tends to favor failure by glide plane fracture when it is heavily decarburized. - Abstract: The influence of high temperature aging treatment on room temperature tensile properties of wrought nickel-base superalloys Alloy 617 and Haynes 230 was investigated. A significant decrease in elongation was observed for Alloy 617 exposed to a heavily oxidizing and decarburizing condition because of coarsening of grain boundary carbides and extensive inter-granular oxidation. On the other hand, Haynes 230 showed much lower ductility when exposed to a heavily carburizing condition, especially at 1000 deg. C because extensive carburization occurred due to a reaction with tungsten. Considerable loss of ductility for Alloy 617 and Haynes 230 was also observed in He-H2-H2O-CO-CO2-CH4 and He-H2O-CO-CO2 environments, which were the slightly oxidizing and decarburizing conditions. Loss of ductility was predominantly associated with brittle inter-granular cracking, while the extent of loss of ductility decreased depending on the decarburization depth. Decarburization was observed more extensively in helium with H2-H2O-CO-CO2-CH4 than helium with H2O-CO-CO2, and for Alloy 617 than for Haynes 230. Finally, the role of H2 in accelerating decarburization is discussed.

  5. Discussion of Base Station Room Development Trend under Multi-Network Cooperation%多网协同下基站机房发展趋势探讨

    Institute of Scientific and Technical Information of China (English)

    钱会; 贝斐峰; 王强

    2013-01-01

    随着通信技术的发展,国内的移动通信网络将面临2G/3G/LTE/WLAN等多网协同的网络建设,网络复用程度的大幅提高对于基站机房的建设也提出了新的要求。首先阐述了基站机房的发展历史,并介绍了基站机房现阶段典型的机房类型及其优缺点,研究了通信行业的发展背景及趋势。最后对基站机房的未来发展趋势进行总结,说明了基站机房未来发展对现网的影响。%With the development of communication technology, the domestic mobile communication network will face 2G/3G/LTE/WLAN multi-network cooperation construction. The increasing network multiplexing degree also has new requirements for the construction of base station room. Firstly, the development history of base station room is given. Secondly the typical types as well as the advantages and disadvantages of base station room at the present stage are introduced, then the development background and trend of communication industry are studied. Finally, the development trend of the future base station room is summarized, while the impact of the future base station room on the existing network is illustrated.

  6. Scatter correction in myocardial thallium SPECT. Needs for optimization of energy window settings in the energy window-based scatter correction techniques

    Energy Technology Data Exchange (ETDEWEB)

    Narita, Yuichiro [Akita Research Institute of Brain and Blood Vessels (Japan); Iida, Hidehiro

    1999-02-01

    Accuracy and limitation of energy-window based scatter correction techniques have been evaluated for myocardial {sup 201}Tl SPECT by means of Monte Carlo simulation. In particular, projection view-dependency of energy distribution of the scattered photons was evaluated. Two geometrical configurations were simulated; namely a homogeneous cylindrical radioactivity located asymmetrically in a homogeneous cylindrical phantom, and a homogeneous ring radioactivity positioned at the myocardial region of a human thorax phantom. Energy spectra were recorded for each projection, and accuracy of the triple-energy window (TEW) method was then evaluation for both phantoms. The energy distribution of the scattered photons was apparently dependent on the projection view. TEW also demonstrated systematic overcorrection for the scatter because of multiple photo peaks around 80 keV, and more importantly, the error was highly dependent on the projection view. The error reached to 35-38% for the view that is the closest to the {sup 201}Tl radioactivity (anterior view in case of the myocardial ring phantom), and was approximately 20% in the opposite view. This view-dependency of the error remained for other energy window settings, and was found to cause significant artifact in the reconstructed myocardial images, typically causing a defect in the anterior myocardial wall. Thus, this study demonstrated the need for optimizing the window settings for each projection view in all energy window-based scatter correction methods. (author)

  7. PET/MR brain imaging: evaluation of clinical UTE-based attenuation correction

    Energy Technology Data Exchange (ETDEWEB)

    Aasheim, Lars Birger [Norwegian University of Science and Technology (NTNU), Department of Circulation and Medical Imaging, Trondheim (Norway); St. Olavs University Hospital, Clinic of Radiology and Nuclear Medicine, Trondheim (Norway); Karlberg, Anna [St. Olavs University Hospital, Clinic of Radiology and Nuclear Medicine, Trondheim (Norway); Goa, Paal Erik [St. Olavs University Hospital, Clinic of Radiology and Nuclear Medicine, Trondheim (Norway); NTNU, Department of Physics, Trondheim (Norway); Haaberg, Asta [NTNU, Department of Neuroscience, Trondheim (Norway); St. Olavs University Hospital, Department of Medical Imaging, Trondheim (Norway); Soerhaug, Sveinung [St. Olavs University Hospital, Department of Thoracic Medicine, Trondheim (Norway); Fagerli, Unn-Merete [St. Olavs University Hospital, Department of Oncology, Trondheim (Norway); NTNU, Department of Cancer Research and Molecular Medicine, Trondheim (Norway); Eikenes, Live [Norwegian University of Science and Technology (NTNU), Department of Circulation and Medical Imaging, Trondheim (Norway)

    2015-08-15

    One of the greatest challenges in PET/MR imaging is that of accurate MR-based attenuation correction (AC) of the acquired PET data, which must be solved if the PET/MR modality is to reach its full potential. The aim of this study was to investigate the performance of Siemens' most recent version (VB20P) of MR-based AC of head PET data, by comparing it to CT-based AC. Methods:{sup 18}F-FDG PET data from seven lymphoma and twelve lung cancer patients examined with a Biograph mMR PET/MR system were reconstructed with both CT-based and MR-based AC, avoiding sources of error arising when comparing PET data from different systems. The resulting images were compared quantitatively by measuring changes in mean SUV in ten different brain regions in both hemispheres, as well as the brainstem. In addition, the attenuation maps (μ maps) were compared regarding volume and localization of cranial bone. The UTE μ maps clearly overestimate the amount of bone in the neck, while slightly underestimating the amount of bone in the cranium, and the localization of bone in the cranial region also differ from the CT μ maps. In air/tissue interfaces in the sinuses and ears, the MRAC method struggles to correctly classify the different tissues. The misclassification of tissue is most likely caused by a combination of artefacts and the insufficiency of the UTE method to accurately separate bone. Quantitatively, this results in a combination of overestimation (0.5-3.6 %) and underestimation (2.7-5.2 %) of PET activity throughout the brain, depending on the proximity to the inaccurate regions. Our results indicate that the performance of the UTE method as implemented in VB20P is close to the theoretical maximum of such an MRAC method in the brain, while it does not perform satisfactorily in the neck or face/nasal area. Further improvement of the UTE MRAC or other available methods for more accurate segmentation of bone should be incorporated. (orig.)

  8. Identifying influential nodes in dynamic social networks based on degree-corrected stochastic block model

    Science.gov (United States)

    Wang, Tingting; Dai, Weidi; Jiao, Pengfei; Wang, Wenjun

    2016-05-01

    Many real-world data can be represented as dynamic networks which are the evolutionary networks with timestamps. Analyzing dynamic attributes is important to understanding the structures and functions of these complex networks. Especially, studying the influential nodes is significant to exploring and analyzing networks. In this paper, we propose a method to identify influential nodes in dynamic social networks based on identifying such nodes in the temporal communities which make up the dynamic networks. Firstly, we detect the community structures of all the snapshot networks based on the degree-corrected stochastic block model (DCBM). After getting the community structures, we capture the evolution of every community in the dynamic network by the extended Jaccard’s coefficient which is defined to map communities among all the snapshot networks. Then we obtain the initial influential nodes of the dynamic network and aggregate them based on three widely used centrality metrics. Experiments on real-world and synthetic datasets demonstrate that our method can identify influential nodes in dynamic networks accurately, at the same time, we also find some interesting phenomena and conclusions for those that have been validated in complex network or social science.

  9. 3D Room Visualization on Android Based Mobile Device (with Philips™’ Surround Sound Music Player

    Directory of Open Access Journals (Sweden)

    Durio Etgar

    2012-12-01

    Full Text Available This project’s specifically purposed as a demo application, so anyone can get the experience of a surround audio room without having to physically involved to it, with a main idea of generating a 3D surround sound room scenery coupled with surround sound in a handier package, namely, a “Virtual Listen Room”. Virtual Listen Room set a foundation of an innovative visualization that later will be developed and released as one of way of portable advertisement. This application was built inside of Android environment. Android device had been chosen as the implementation target, since it leaves massive development spaces and mostly contains essential components needed on this project, including graphic processor unit (GPU.  Graphic manipulation can be done using an embedded programming interface called OpenGL ES, which is planted in all Android devices generally. Further, Android has a Accelerometer Sensor that is needed to be coupled with scene to produce a dynamic movement of the camera. Surround sound effect can be reached with a decoder from Phillips called MPEG Surround Sound Decoder. To sum the whole project, we got an application with sensor-dynamic 3D room visualization coupled with Philips’ Surround Sound Music Player. We can manipulate several room’s properties; Subwoofer location, Room light, and how many speakers inside it, the application itself works well despite facing several performance problems before, later to be solved. [Keywords : Android,Visualization,Open GL; ES; 3D; Surround Sensor

  10. 3D Room Visualization on Android Based Mobile Device (with Philips™’ Surround Sound Music Player

    Directory of Open Access Journals (Sweden)

    Durio Etgar

    2013-01-01

    Full Text Available This project’s specifically purposed as a demo application, so anyone can get the experience of a surround audio room without having to physically involved to it, with a main idea of generating a 3D surround sound room scenery coupled with surround sound in a handier package, namely, a “Virtual Listen Room”. Virtual Listen Room set a foundation of an innovative visualization that later will be developed and released as one of way of portable advertisement. This application was built inside of Android environment. Android device had been chosen as the implementation target, since it leaves massive development spaces and mostly contains essential components needed on this project, including graphic processor unit (GPU. Graphic manipulation can be done using an embedded programming interface called OpenGL ES, which is planted in all Android devices generally. Further, Android has a Accelerometer Sensor that is needed to be coupled with scene to produce a dynamic movement of the camera. Surround sound effect can be reached with a decoder from Phillips called MPEG Surround Sound Decoder. To sum the whole project, we got an application with sensor-dynamic 3D room visualization coupled with Philips’ Surround Sound Music Player. We can manipulate several room’s properties; Subwoofer location, Room light, and how many speakers inside it, the application itself works well despite facing several performance problems before, later to be solved.

  11. Photometric correction for an optical CCD-based system based on the sparsity of an eight-neighborhood gray gradient.

    Science.gov (United States)

    Zhang, Yuzhong; Zhang, Yan

    2016-07-01

    In an optical measurement and analysis system based on a CCD, due to the existence of optical vignetting and natural vignetting, photometric distortion, in which the intensity falls off away from the image center, affects the subsequent processing and measuring precision severely. To deal with this problem, an easy and straightforward method used for photometric distortion correction is presented in this paper. This method introduces a simple polynomial fitting model of the photometric distortion function and employs a particle swarm optimization algorithm to get these model parameters by means of a minimizing eight-neighborhood gray gradient. Compared with conventional calibration methods, this method can obtain the profile information of photometric distortion from only a single common image captured by the optical CCD-based system, with no need for a uniform luminance area source used as a standard reference source and relevant optical and geometric parameters in advance. To illustrate the applicability of this method, numerical simulations and photometric distortions with different lens parameters are evaluated using this method in this paper. Moreover, the application example of temperature field correction for casting billets also demonstrates the effectiveness of this method. The experimental results show that the proposed method is able to achieve the maximum absolute error for vignetting estimation of 0.0765 and the relative error for vignetting estimation from different background images of 3.86%. PMID:27409217

  12. Event-based knowledge elicitation of operating room management decision-making using scenarios adapted from information systems data

    Directory of Open Access Journals (Sweden)

    Epstein Richard H

    2011-01-01

    Full Text Available Abstract Background No systematic process has previously been described for a needs assessment that identifies the operating room (OR management decisions made by the anesthesiologists and nurse managers at a facility that do not maximize the efficiency of use of OR time. We evaluated whether event-based knowledge elicitation can be used practically for rapid assessment of OR management decision-making at facilities, whether scenarios can be adapted automatically from information systems data, and the usefulness of the approach. Methods A process of event-based knowledge elicitation was developed to assess OR management decision-making that may reduce the efficiency of use of OR time. Hypothetical scenarios addressing every OR management decision influencing OR efficiency were created from published examples. Scenarios are adapted, so that cues about conditions are accurate and appropriate for each facility (e.g., if OR 1 is used as an example in a scenario, the listed procedure is a type of procedure performed at the facility in OR 1. Adaptation is performed automatically using the facility's OR information system or anesthesia information management system (AIMS data for most scenarios (43 of 45. Performing the needs assessment takes approximately 1 hour of local managers' time while they decide if their decisions are consistent with the described scenarios. A table of contents of the indexed scenarios is created automatically, providing a simple version of problem solving using case-based reasoning. For example, a new OR manager wanting to know the best way to decide whether to move a case can look in the chapter on "Moving Cases on the Day of Surgery" to find a scenario that describes the situation being encountered. Results Scenarios have been adapted and used at 22 hospitals. Few changes in decisions were needed to increase the efficiency of use of OR time. The few changes were heterogeneous among hospitals, showing the usefulness of

  13. Mask CD uniformity improvement by electron scanning exposure based Global Loading Effect Correction

    Science.gov (United States)

    Li, Rivan; Tian, Eric; Shi, Irene; Guo, Eric; Lu, Max

    2015-07-01

    Critical Dimension (CD) Uniformity is one of the necessary parameters to assure good performance and reliable functionality of any integrated circuit (IC), and towards the advanced technology node 28nm and beyond, corresponding CD Uniformity becomes more and more crucial. It is found that bad mask CD Uniformity is a significant error source at 28nm process. The CD Uniformity on mask, if not controlled well, will badly impact wafer CD performance, and it has been well-studied that CD Uniformity issue from gate line-width in transistors would affect the device performance directly. In this paper we present a novel solution for mask global CD uniformity error correction, which is called as global loading effect correction (GLEC) method and applied nesting in the mask exposure map during the electron beam exposure. There are factors such as global chip layout, writing sequence and chip pattern density distribution (Global Loading), that work on the whole mask CD Uniformity, especially Global Loading is the key factor related to mask global CD error. From our experimental results, different pattern density distribution on mask significantly influenced the final mask CD Uniformity: the mask with undulating pattern density distribution provides much worse CD Uniformity than that with uniform one. Therefore, a GLEC model based on pattern density has been created to compensate the global error during the electron beam exposure, which has been proved to be efficacious to improve mask global CD Uniformity performance. Furthermore, it 's also revealed that pattern type is another important impact factor, and GLEC coefficient need be modified due to the specific pattern type (e.g. dense line-space only, iso-space only or an average of them) to improve the corresponding mask CD uniformity.

  14. Kinematic Model-Based Pedestrian Dead Reckoning for Heading Correction and Lower Body Motion Tracking

    Directory of Open Access Journals (Sweden)

    Min Su Lee

    2015-11-01

    Full Text Available In this paper, we present a method for finding the enhanced heading and position of pedestrians by fusing the Zero velocity UPdaTe (ZUPT-based pedestrian dead reckoning (PDR and the kinematic constraints of the lower human body. ZUPT is a well known algorithm for PDR, and provides a sufficiently accurate position solution for short term periods, but it cannot guarantee a stable and reliable heading because it suffers from magnetic disturbance in determining heading angles, which degrades the overall position accuracy as time passes. The basic idea of the proposed algorithm is integrating the left and right foot positions obtained by ZUPTs with the heading and position information from an IMU mounted on the waist. To integrate this information, a kinematic model of the lower human body, which is calculated by using orientation sensors mounted on both thighs and calves, is adopted. We note that the position of the left and right feet cannot be apart because of the kinematic constraints of the body, so the kinematic model generates new measurements for the waist position. The Extended Kalman Filter (EKF on the waist data that estimates and corrects error states uses these measurements and magnetic heading measurements, which enhances the heading accuracy. The updated position information is fed into the foot mounted sensors, and reupdate processes are performed to correct the position error of each foot. The proposed update-reupdate technique consequently ensures improved observability of error states and position accuracy. Moreover, the proposed method provides all the information about the lower human body, so that it can be applied more effectively to motion tracking. The effectiveness of the proposed algorithm is verified via experimental results, which show that a 1.25% Return Position Error (RPE with respect to walking distance is achieved.

  15. Room temperature analysis of dielectric function of ZnO-based thin film on fused quartz substrate

    Energy Technology Data Exchange (ETDEWEB)

    Kurniawan, Robi; Sutjahja, Inge M.; Winata, Toto [Department of Physics, Institut Teknologi Bandung, Ganesa 10 Bandung 40132 (Indonesia); Rusydi, Andrivo; Darma, Yudi, E-mail: yudi@fi.itb.ac.id [Department of Physics, Institut Teknologi Bandung, Ganesa 10 Bandung 40132 (Indonesia); Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, Singapore 117603 (Singapore); NUSNNI-Nanocore, Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore)

    2015-09-30

    A set of sample consist of pure ZnO and Cu-doped ZnO film were grown on fused-quartz substrates using pulsed laser deposition (PLD) technique. Here, we report room temperature spectroscopic ellipsometry analysis (covering energy range of 0.5 to 6.3 eV) of pure ZnO film and Cu doped ZnO film at 8 in at. %. The thickness of pure ZnO and Cu-doped ZnO film using in this study is about 350 nm. To extract the dielectric function of ZnO thin film, multilayer modeling is performed which takes into account reflections at each interface through Fresnel coefficients. This method based on Drude-Lorentz models that connect with Kramers-Kronig relations. The best fitting of Ψ (amplitude ratio) and Δ (phase difference) taken by SE measurement are obtained reasonably well by mean the universal fitting of three different photon incident angles. The imaginary part of dielectric function (ε{sub 2}) show the broad peak at around 3.3 eV assigned as combination of optical band energy edge with excitonic states. The exitonic states could not be observed clearly in this stage. The evolution of extracted dielectric function is observable by introducing 8% Cu as indicated by decreasing of excitonic intensity. This result indicates the screening of excitonic state. This study will bring us to have a good undestanding for the role of Cu impurities for ZnO thin films.

  16. Localization Corrections for Mobile Laser Scanner Using Local Support-Based Outlier Filtering

    Science.gov (United States)

    Lehtola, V. V.; Virtanen, J.-P.; Rönnholm, P.; Nüchter, A.

    2016-06-01

    Following the pioneering work introduced in [Lehtola et al., ISPRS J. Photogramm. Remote Sens. 99, 2015, pp. 25-29], we extend the state-of-the-art intrinsic localization solution for a single two-dimensional (2D) laser scanner from one into (quasi) three dimensions (3D). By intrinsic localization, we mean that no external sensors are used to localize the scanner, such as inertial measurement devices (IMU) or global navigation satellite systems (GNSS). Specifically, the proposed method builds on a novel concept of local support-based filtering of outliers, which enables the use of six degrees-of-freedom (DoF) simultaneous localization and mapping (SLAM) for the purpose of enacting appropriate trajectory corrections into the previous one-dimensional solution. Moreover, the local support-based filtering concept is platform independent, and is therefore likely to be widely generalizable. The here presented overall method is yet limited into quasi-3D by its inability to recover trajectories with steep curvature, but in the future, it may be further extended into full 3D.

  17. A Histogram-Based Static-Error Correction Technique for Flash ADCs

    Institute of Scientific and Technical Information of China (English)

    Armin Jalili; J Jacob Wikner; Sayed Masoud Sayedi; Rasoul Dehghani

    2011-01-01

    High-speed, high-accuracy data converters are attractive for use in most RF applications. Such converters allow direct conversion to occur between the digital baseband and the antenna. However, high speed and high accuracy make the analog components in a converter more complex, and this complexity causes more power to be dissipated than if a traditional approach were taken. A static calibration technique for flash analog-to-digital converters (ADCs) is discussed in this paper. The calibration is based onhistogram test methods, and equivalent errors in the flash ADC comparators are estimated in the digital domain without any significant changes being made to the ADC comparators. In the trimming process, reference voltages are adjusted to compensate for static errors. Behavioral-level simulations of a moderate-resolution 8-bit flash ADC show that, for typical errors, ADC performance is considerably improved by the proposed technique. As a result of calibration, the differential no.nlinearities (DNLs) are reduced on average from 4 LSB to 0.5 LSB, and the integral nonlinearities (INLs) are reduced on average from 4.2 LSB to 0.35 LSB. Implementation issues for this proposed technique are discussed in our subsequent paper, “A Histogram-Based Static-Error Correction Technique for Flash ADCs: Implementation Aspects. ”

  18. [Virtual room of gastroenterology].

    Science.gov (United States)

    Spinelli, Osvaldo Mateo; Fittipaldi, Mónica Elsa; Henderson, Eduardo; Krabshuis, Justus Hendrik

    2010-12-01

    The amount of published information and its continuing growth can no longer be managed by an individual searcher. One of today's great challenges for the academic researcher and clinician is to find a relevant scientific article using bibliographic search strategies. We aimed to design and build a Virtual Room of Gastroenterology (VRG) generating real-time automated search strategies and producing bibliographic and full text search results. These results update and complement with the latest evidence the Clinical Guideline Program of the World Gastroenterology Organisation. The HTML driven interface provides a series of pre-formulated MeSH based search strategies for each Aula. For each topic between 10 and 20 specific terms, qualifiers and subheadings are identified. The functionality of the VRG is based on the PubMed's characteristic that allows a search strategy to be captured as a web address. The VRG is available in Spanish and English, and the access is free. There are 28 rooms currently available. All together these rooms provide an advanced bibliographic access using more than 900 pre-programmed MeSH driven strategies. In a further very recent development some of the topics of VRG now allow cascade based searches. These searches look at resource sensitive options and possible ethnic difference per topic. The VRG allows significant reductions in time required to design and carry out complex bibliographic searches in the areas of gastroenterology, hepatology and endoscopy. The system updates automatically in real-time thus ensuring the currency of the results.

  19. A contrast correction method for dental images based on histogram registration

    OpenAIRE

    Economopoulos, TL; Asvestas, PA; Matsopoulos, GK; Gröndahl, K; Gröndahl, H-G

    2010-01-01

    Contrast correction is often required in digital subtraction radiography when comparing medical data acquired over different time periods owing to dissimilarities in the acquisition process. This paper focuses on dental radiographs and introduces a novel approach for correcting the contrast in dental image pairs.

  20. MR-based motion correction for PET imaging using wired active MR microcoils in simultaneous PET-MR: Phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chuan; Brady, Thomas J.; El Fakhri, Georges; Ouyang, Jinsong, E-mail: ouyang.jinsong@mgh.harvard.edu [Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114 and Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115 (United States); Ackerman, Jerome L. [Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129 and Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115 (United States); Petibon, Yoann [Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States)

    2014-04-15

    Purpose: Artifacts caused by head motion present a major challenge in brain positron emission tomography (PET) imaging. The authors investigated the feasibility of using wired active MR microcoils to track head motion and incorporate the measured rigid motion fields into iterative PET reconstruction. Methods: Several wired active MR microcoils and a dedicated MR coil-tracking sequence were developed. The microcoils were attached to the outer surface of an anthropomorphic{sup 18}F-filled Hoffman phantom to mimic a brain PET scan. Complex rotation/translation motion of the phantom was induced by a balloon, which was connected to a ventilator. PET list-mode and MR tracking data were acquired simultaneously on a PET-MR scanner. The acquired dynamic PET data were reconstructed iteratively with and without motion correction. Additionally, static phantom data were acquired and used as the gold standard. Results: Motion artifacts in PET images were effectively removed by wired active MR microcoil based motion correction. Motion correction yielded an activity concentration bias ranging from −0.6% to 3.4% as compared to a bias ranging from −25.0% to 16.6% if no motion correction was applied. The contrast recovery values were improved by 37%–156% with motion correction as compared to no motion correction. The image correlation (mean ± standard deviation) between the motion corrected (uncorrected) images of 20 independent noise realizations and static reference was R{sup 2} = 0.978 ± 0.007 (0.588 ± 0.010, respectively). Conclusions: Wired active MR microcoil based motion correction significantly improves brain PET quantitative accuracy and image contrast.

  1. MR-based motion correction for PET imaging using wired active MR microcoils in simultaneous PET-MR: Phantom study

    International Nuclear Information System (INIS)

    Purpose: Artifacts caused by head motion present a major challenge in brain positron emission tomography (PET) imaging. The authors investigated the feasibility of using wired active MR microcoils to track head motion and incorporate the measured rigid motion fields into iterative PET reconstruction. Methods: Several wired active MR microcoils and a dedicated MR coil-tracking sequence were developed. The microcoils were attached to the outer surface of an anthropomorphic18F-filled Hoffman phantom to mimic a brain PET scan. Complex rotation/translation motion of the phantom was induced by a balloon, which was connected to a ventilator. PET list-mode and MR tracking data were acquired simultaneously on a PET-MR scanner. The acquired dynamic PET data were reconstructed iteratively with and without motion correction. Additionally, static phantom data were acquired and used as the gold standard. Results: Motion artifacts in PET images were effectively removed by wired active MR microcoil based motion correction. Motion correction yielded an activity concentration bias ranging from −0.6% to 3.4% as compared to a bias ranging from −25.0% to 16.6% if no motion correction was applied. The contrast recovery values were improved by 37%–156% with motion correction as compared to no motion correction. The image correlation (mean ± standard deviation) between the motion corrected (uncorrected) images of 20 independent noise realizations and static reference was R2 = 0.978 ± 0.007 (0.588 ± 0.010, respectively). Conclusions: Wired active MR microcoil based motion correction significantly improves brain PET quantitative accuracy and image contrast

  2. First principles based design and experimental evidence for a ZnO-based ferromagnet at room temperature.

    Science.gov (United States)

    Sluiter, Marcel H F; Kawazoe, Y; Sharma, Parmanand; Inoue, A; Raju, A R; Rout, C; Waghmare, U V

    2005-05-13

    The introduction of ferromagnetic order in ZnO results in a transparent piezoelectric ferromagnet and further expands its already wide range of applications into the emerging field of spintronics. Through an analysis of density functional calculations we determine the nature of magnetic interactions for transition metals doped ZnO and develop a physical picture based on hybridization, superexchange, and double exchange that captures chemical trends. We identify a crucial role of defects in the observed weak and preparation sensitive ferromagnetism in ZnO:Mn and ZnO:Co. We predict and explain co-doping of Li and Zn interstitials to both yield ferromagnetism in ZnO:Co, in contrast with earlier insights, and verify it experimentally. PMID:15904408

  3. Theory and investigation of acoustic multiple-input multiple-output systems based on spherical arrays in a room.

    Science.gov (United States)

    Morgenstern, Hai; Rafaely, Boaz; Zotter, Franz

    2015-11-01

    Spatial attributes of room acoustics have been widely studied using microphone and loudspeaker arrays. However, systems that combine both arrays, referred to as multiple-input multiple-output (MIMO) systems, have only been studied to a limited degree in this context. These systems can potentially provide a powerful tool for room acoustics analysis due to the ability to simultaneously control both arrays. This paper offers a theoretical framework for the spatial analysis of enclosed sound fields using a MIMO system comprising spherical loudspeaker and microphone arrays. A system transfer function is formulated in matrix form for free-field conditions, and its properties are studied using tools from linear algebra. The system is shown to have unit-rank, regardless of the array types, and its singular vectors are related to the directions of arrival and radiation at the microphone and loudspeaker arrays, respectively. The formulation is then generalized to apply to rooms, using an image source method. In this case, the rank of the system is related to the number of significant reflections. The paper ends with simulation studies, which support the developed theory, and with an extensive reflection analysis of a room impulse response, using the platform of a MIMO system.

  4. Theory and investigation of acoustic multiple-input multiple-output systems based on spherical arrays in a room.

    Science.gov (United States)

    Morgenstern, Hai; Rafaely, Boaz; Zotter, Franz

    2015-11-01

    Spatial attributes of room acoustics have been widely studied using microphone and loudspeaker arrays. However, systems that combine both arrays, referred to as multiple-input multiple-output (MIMO) systems, have only been studied to a limited degree in this context. These systems can potentially provide a powerful tool for room acoustics analysis due to the ability to simultaneously control both arrays. This paper offers a theoretical framework for the spatial analysis of enclosed sound fields using a MIMO system comprising spherical loudspeaker and microphone arrays. A system transfer function is formulated in matrix form for free-field conditions, and its properties are studied using tools from linear algebra. The system is shown to have unit-rank, regardless of the array types, and its singular vectors are related to the directions of arrival and radiation at the microphone and loudspeaker arrays, respectively. The formulation is then generalized to apply to rooms, using an image source method. In this case, the rank of the system is related to the number of significant reflections. The paper ends with simulation studies, which support the developed theory, and with an extensive reflection analysis of a room impulse response, using the platform of a MIMO system. PMID:26627773

  5. Avoidance of moulds in living rooms; Schimmelpilze in Wohnraeumen vermeiden

    Energy Technology Data Exchange (ETDEWEB)

    Anda Gonzalez, Leticia de; Spitzner, Martin H.

    2011-07-01

    The contribution under consideration supplies valuable recommendations regarding the avoidance of a growth of mould fungi in living rooms. Information about a correct ventilation behaviour, a correct heating behaviour, a correct positioning of furniture, a correct attachment of wall coverings and measures of the user behaviour are given.

  6. Sensitivity in the Correction of Long-Range Ground-Based Thermal Data.

    Science.gov (United States)

    Hancock, Anson; James, Mike; Ganci, Gaetana; Harris, Andrew

    2016-04-01

    Ground-based thermal remote sensing is a valuable tool for the study and monitoring of volcanoes and their hazards. However, permanent monitoring installations often require the camera to be positioned at relatively long ranges from the target (i.e. >1000 m). These types of long-range deployments have been seldom analysed quantitatively due primarily to factors such as atmospheric attenuation and across-image variations in the target path-length resulting in substantial uncertainty in the derived surface temperatures. Here we examine the sensitivity of measurements at three different apparent temperatures (400, 500 and 600 K) to uncertainty in the atmospheric conditions and type of path for the INGV-Catania (Etna, Sicily) permanently installed thermal camera. The camera is located at Mount Cagliato at an elevation of 1154 m asl and looks to the summit area at ˜3000 m asl, over a distance of ˜8.5 km. Analysis was carried out using MODTRAN to calculate atmospheric transmittance and upwelling radiance values for the different scenarios. We then calculated corrected surface temperatures by applying an atmospheric correction using two different temperature-to-radiance methods: a top-hat wavelength integrated based method supplied by FLIR Systems in their ThermaCam Researcher software and a mid-wavelength value method using the Planck equation. Results indicate that calculated surface temperatures between the two methods differ by as much as 382.5 K over a path-length of 8.5 km. Over path lengths between 1 and 8.5 km, changing the atmospheric temperature to 288.15 (15 oC), 293.15 (20 oC) and 298.15 K (25 oC) resulted in increases in calculated surface temperatures of 1.7-72.4 K using the FLIR top-hat method and 1.4-205.5 K using the mid-wavelength method. For relative humidities of 40, 50 and 60 %, increases in calculated surface temperatures of 1.0-58.7 K and 1.0-148.9 K using the FLIR top-hat and mid-wavelength methods, respectively. We also found that calculated

  7. A continuous wavelet transform-based method for time-frequency analysis of artefact-corrected heart rate variability data

    International Nuclear Information System (INIS)

    Time-frequency analysis of heart rate variability (HRV) provides relevant clinical information. However, time-frequency analysis is very sensitive to artefacts. Artefacts that are present in heart rate recordings may be corrected, but this reduces the variability in the signal and therefore adversely affects the accuracy of calculated spectral estimates. To overcome this limitation of traditional techniques for time-frequency analysis, a new continuous wavelet transform (CWT)-based method was developed in which parts of the scalogram that have been affected by artefact correction are excluded from power calculations. The method was evaluated by simulating artefact correction on HRV data that were originally free of artefacts. Commonly used spectral HRV parameters were calculated by the developed method and by the short-time Fourier transform (STFT), which was used as a reference. Except for the powers in the very low-frequency and low-frequency (LF) bands, powers calculated by the STFT proved to be extremely sensitive to artefact correction. The CWT-based calculations in the high-frequency and very high-frequency bands corresponded well with their theoretical values. The standard deviations of these powers, however, increase with the number of corrected artefacts which is the result of the non-stationarity of the R–R interval series that were analysed. The powers calculated in the LF band turned out to be slightly sensitive to artefact correction, but the results were acceptable up to 20% artefact correction. Therefore, the CWT-based method provides a valuable alternative for the analysis of HRV data that cannot be guaranteed to be free of artefacts

  8. Positron-based attenuation correction for Positron Emission Tomography data using MCNP6 code

    Directory of Open Access Journals (Sweden)

    M. Saeed

    2016-01-01

    Full Text Available This paper presents the Monte Carlo simulation of the attenuation correction for Positron Emission Tomography (PET data using MCNP6 code. Two attenuation correction maps have been generated, one for correcting the attenuation effect in a homogeneous phantom, which is a cylindrical volume of water and the other for correcting the attenuation effect in a heterogeneous phantom, which is a cylindrical volume of water within which, there are two small cylinders of bone-equivalent materials. These maps are derived from the data acquired as a result of transmission scans using a positron-emitting rod source. The attenuation map generated using this method does not need to be scaled because it is directly built for an energy of 511 keV. For each phantom, three types of simulations are done, one to estimate the radiotracer distribution in the phantom (emission scan and two to estimate the distribution of attenuation coefficients in this phantom (transmission scans, the first with a blank field of view (FOV and the second when the phantom exists in the FOV. From the transmission scans data, the attenuation map for each phantom is derived and after that it has been applied to the corresponding emission scan data during PET image reconstruction process to obtain the attenuation-corrected image. The images of the radiotracer distribution in each phantom reached in this study illustrate the quantitative and qualitative improvements in the image quality after attenuation correction than that before the attenuation correction.

  9. 33 CFR 52.81 - Reading room and index.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Reading room and index. 52.81... FOR CORRECTION OF MILITARY RECORDS OF THE COAST GUARD Public Access to Decisions § 52.81 Reading room... at a public reading room. Final decisions created on or after November 1, 1996, shall be...

  10. DVS for On-Chip Bus Designs Based on Timing Error Correction

    CERN Document Server

    Kaul, Himanshu; Blaauw, David; Mudge, Trevor; Austin, Todd

    2011-01-01

    On-chip buses are typically designed to meet performance constraints at worst-case conditions, including process corner, temperature, IR-drop, and neighboring net switching pattern. This can result in significant performance slack at more typical operating conditions. In this paper, we propose a dynamic voltage scaling (DVS) technique for buses, based on a double sampling latch which can detect and correct for delay errors without the need for retransmission. The proposed approach recovers the available slack at non-worst-case operating points through more aggressive voltage scaling and tracks changing conditions by monitoring the error recovery rate. Voltage margins needed in traditional designs to accommodate worst-case performance conditions are therefore eliminated, resulting in a significant improvement in energy efficiency. The approach was implemented for a 6mm memory read bus operating at 1.5GHz (0.13 $\\mu$m technology node) and was simulated for a number of benchmark programs. Even at the worst-case ...

  11. A Trajectory Correction based on Multi-Step Lining-up for the CLIC Main Linac

    CERN Document Server

    D'Amico, T E

    1999-01-01

    In the CLIC main linac it is very important to minimise the trajectory excursion and consequently the emittance dilution in order to obtain the required luminosity. Several algorithms have been proposed and lately the ballistic method has proved to be very effective. The trajectory method described in this Note retains the main advantages of the latter while adding some interesting features. It is based on the separation of the unknown variables like the quadrupole misalignments, the offset and slope of the injection straight line and the misalignments of the beam position monitors (BPM). This is achieved by referring the trajectory relatively to the injection line and not to the average pre-alignment line and by using two trajectories each corresponding to slightly different quadrupole strengths. A reference straight line is then derived onto which the beam is bent by a kick obtained by moving the first quadrupole. The other quadrupoles are then aligned on that line. The quality of the correction depends mai...

  12. CMF Signal Processing Method Based on Feedback Corrected ANF and Hilbert Transformation

    Directory of Open Access Journals (Sweden)

    Tu Yaqing

    2014-02-01

    Full Text Available In this paper, we focus on CMF signal processing and aim to resolve the problems of precision sharp-decline occurrence when using adaptive notch filters (ANFs for tracking the signal frequency for a long time and phase difference calculation depending on frequency by the sliding Goertzel algorithm (SGA or the recursive DTFT algorithm with negative frequency contribution. A novel method is proposed based on feedback corrected ANF and Hilbert transformation. We design an index to evaluate whether the ANF loses the signal frequency or not, according to the correlation between the output and input signals. If the signal frequency is lost, the ANF parameters will be adjusted duly. At the same time, singular value decomposition (SVD algorithm is introduced to reduce noise. And then, phase difference between the two signals is detected through trigonometry and Hilbert transformation. With the frequency and phase difference obtained, time interval of the two signals is calculated. Accordingly, the mass flow rate is derived. Simulation and experimental results show that the proposed method always preserves a constant high precision of frequency tracking and a better performance of phase difference measurement compared with the SGA or the recursive DTFT algorithm with negative frequency contribution

  13. A Minimum-Entropy Based Residual Range Cell Migration Correction for Bistatic Forward-Looking SAR

    Directory of Open Access Journals (Sweden)

    Yuebo Zha

    2016-02-01

    Full Text Available For bistatic forward-looking synthetic aperture radar (BFSAR, motion errors induce two adverse effects on the echo, namely, azimuth phase error and residual range cell migration (RCM. Under the presumption that residual RCM is within a range resolution cell, residual RCM can be neglected, and azimuth phase error can be compensated utilizing autofocus methods. However, in the case that residual RCM exceeds the range resolution, two-dimensional defocus would emerge in the final image. Generally speaking, residual RCM is relatively small and can be neglected in monostatic SAR, while the unique characteristics of BFSAR makes the residual RCM exceeding range resolution cell inevitable. Furthermore, the excessive residual migration is increasingly encountered as resolutions become finer. To cope with such a problem, minimum-entropy based residual RCM correction method is developed in this paper. The proposed method eliminates the necessity of the parametric model when estimating the residual RCM. Moreover, it meets the practical needs of BFSAR owing to no requirement of exhaustive computation. Simulations validate the effectiveness of the proposed method.

  14. Position mapping and a uniformity correction method for small-animal SPECT based on connected regional recognition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qiushi; Lu, Yanye [Department of Biomedicine and Engineering, College of Engineering, Peking University, No. 5 Yiheyuan Road, Beijing 100871 (China); Yang, Kun [Department of Control Technology and Instrument, College of Quality and Technical Supervision, Hebei University, No.180 Wusi East Road, Baoding 071000 (China); Ren, Qiushi, E-mail: renqsh@coe.pku.edu.cn [Department of Biomedicine and Engineering, College of Engineering, Peking University, No. 5 Yiheyuan Road, Beijing 100871 (China)

    2013-03-11

    We describe a novel position mapping and the uniformity correction method to improve the performance of small animal single-photon emission computed tomography (SPECT) imaging. The SPECT system consists of a cerium doped lutetium−yttrium oxyorthosilicate (LYSO) scintillation crystal (22×22 pixel array, 2 mm×2 mm×3 mm pixel size), a position sensitive photomultiplier tube (H8500c, Hamamatsu Photonics Co., Ltd., Shizuoka Prefecture, Japan), and a parallel-hole collimator (Nuclear Fields Pty. Ltd., St. Marys, Australia). The position mapping method was based on a connected regional recognition algorithm. We present the algorithm and step-by-step details of image boundary detection, dynamic binarization, connected regional recognition, center-of-gravity computing, and look-up table establishment. The position mapping and uniformity correction tables were generated and applied to the SPECT projection data. The corrected projection images demonstrated that this correction method improved the uniformity of the raw projection image by ∼16%. The preliminary SPECT reconstruction results (using algebraic reconstruction technology) are also presented. A comparison between the reconstructed images before and after correction further confirms the performance of this correction method.

  15. Semi-Automated Correction Tools for Mathematics-Based Exercises in MOOC Environments

    Directory of Open Access Journals (Sweden)

    Alberto Corbi

    2015-06-01

    Full Text Available Massive Open Online Courses (MOOCs allow the participation of hundreds of students who are interested in a wide range of areas. Given the huge numbers enrolled, it is almost impossible to give complex homework to students and have it carefully corrected and reviewed by a tutor or assistant professor. In this paper, we present a software framework that aims at assisting teachers in MOOCs during correction tasks for mathematics exercises. This framework might suit maths, physics or technical subjects. As a test experience, we apply it to 300+ physics homework bulletins from 80+ students. Test results show our solution can prove very useful in guiding assistant teachers during correction shifts.

  16. An improved tip-loss correction based on vortex code results

    DEFF Research Database (Denmark)

    Branlard, Emmanuel; Dixon, Kristian; Gaunaa, Mac

    Standard blade element momentum(BEM) codes use Prandtl’s tip-loss correction which relies on simplified vortex theory under the assumption of optimal operating condition and no wake expansion. A new tip-loss correction for implementation in BEM codes has been developed using a lifting-line code...... to account for the effect of wake expansion, roll-up and distortion under any operating conditions. A database of tip-loss corrections is established for further use in BEM codes. Using this model a more physical representation of the flow and hence a better assessment of the performance of the turbine...... by BEM codes is expected....

  17. An improved tip-loss correction based on vortex code results

    DEFF Research Database (Denmark)

    Branlard, Emmanuel; Dixon, Kristian; Gaunaa, Mac

    2012-01-01

    Standard blade element momentum(BEM) codes use Prandtl’s tip-loss correction which relies on simplified vortex theory under the assumption of optimal operating condition and no wake expansion. A new tip-loss correction for implementation in BEM codes has been developed using a lifting-line code...... to account for the effect of wake expansion, roll-up and distortion under any operating conditions. A database of tip-loss corrections is established for further use in BEM codes. Using this model a more physical representation of the flow and hence a better assessment of the performance of the turbine...... by BEM codes is expected....

  18. Low Cycle Fatigue Behavior of Alloy 617 Base Metal and Welded Joints at Room Temperature and 850 .deg. C for VHTR Applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seon Jin; Dew, Rando T. [Pukyong National Univ., Busan (Korea, Republic of); Kim, Woo Gon; Kim, Min Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Low cycle fatigue (LCF) is an important design consideration for high temperature IHX components. Moreover, some of the components are joined by welding techniques and therefore the welded joints are unavoidable in the construction of mechanical structures. Since Alloy 617 was introduced in early 1970s, many attempts have been made in the past two decades to evaluate the LCF and creep-fatigue behavior in Alloy 617 base metal at room temperature and high temperature. However, little research has focused on the evaluation and characterization of the Alloy 617 welded joints. butt-welded joint specimens was performed at room temperature and 850 .deg. C. Fatigue lives of GTAW welded joint specimens were lower than those of base metal specimens. LCF cracking and failure in welded specimens initiated in the weld metal zone and followed transgranluar dendritic paths for both at RT and 850 .deg. C.

  19. The research of land covers classification based on waveform features correction of full-waveform LiDAR

    Science.gov (United States)

    Zhou, Mei; Liu, Menghua; Zhang, Zheng; Ma, Lian; Zhang, Huijing

    2015-10-01

    In order to solve the problem of insufficient classification types and low classification accuracy using traditional discrete LiDAR, in this paper, the waveform features of Full-waveform LiDAR were analyzed and corrected to be used for land covers classification. Firstly, the waveforms were processed, including waveform preprocessing, waveform decomposition and features extraction. The extracted features were distance, amplitude, waveform width and the backscattering cross-section. In order to decrease the differences of features of the same land cover type and further improve the effectiveness of the features for land covers classification, this paper has made comprehensive correction on the extracted features. The features of waveforms obtained in Zhangye were extracted and corrected. It showed that the variance of corrected features can be reduced by about 20% compared to original features. Then classification ability of corrected features was clearly analyzed using the measured waveform data with different characteristics. To further verify whether the corrected features can improve the classification accuracy, this paper has respectively classified typical land covers based on original features and corrected features. Since the features have independently Gaussian distribution, the Gaussian mixture density model (GMDM) was put forward to be the classification model to classify the targets as road, trees, buildings and farmland in this paper. The classification results of these four land cover types were obtained according to the ground truth information gotten from CCD image data of the targets region. It showed that the classification accuracy can be improved by about 8% when the corrected features were used.

  20. The broad base columellar strut for correction of retracted columella and under rotated tip

    Directory of Open Access Journals (Sweden)

    Amr N. Rabie

    2016-07-01

    Full Text Available Objective: To describe the technique and to detect the efficacy of the broad base columellar strut in correcting retracted columella and under rotated nasal tip. Design: Retrospective chart review. Setting: University-affiliated medical center. Methods: The charts and photographs of patients suffering from columellar retraction with acute columellar-labial angle were reviewed. The columellar-labial angle and the nasal tip projection were measured and calculated from the photos and the columellar show was measured using a fine caliper. Results: The study included 17 patients, 12 females and 5 males with a mean age of 30.2 years ranging from 19 to 49 years, 14 patients had primary surgery while 3 were revision cases, Preoperative columellar-labial angle ranged from 75° to 86° with a mean 82.06 ± 4.08458 SD, while postoperatively it ranged from 92° to 105° with a mean 97.12° ± 3.9825 SD. Columellar show ranged preoperatively from 0.4 to 1.7 mm with a mean 0.94 mm ± 0.38739 SD while postoperatively it ranged from 2.5 to 3.5 mm with a mean of 2.65 mm ± 0.38098 SD. Nasal tip projection preoperatively ranged from 0.45 to 0.58 and postoperatively from 0.51 to 0.59. Conclusions: The broad base columellar strut technique is simple, easy, does not cause excessive tip stiffness and reduces the need to use the plumbing graft in conjunction with the columellar strut, and should help in increasing tip rotation and columellar show reliably and may add to tip projection as required.

  1. 基于Unity3D的房间仿真技术%Room simulation technology based on Unity3D

    Institute of Scientific and Technical Information of China (English)

    韩桂明; 周凌; 赵志鹏

    2014-01-01

    随着虚拟现实技术的不断发展,3D软件平台在虚拟现实领域起到了关键的作用。本文主要讨论基于Unity3D平台针对虚拟校园的房间仿真关键技术研究及其实现。其内容主要可分为房间3D建模设计和对房间的基本操作设计两个部分。房间的3D建模利用的是3DMax建模软件实现的,其中包括对房间墙壁、窗户、门及内部设备等模型的创建。对房间的基本操作主要是利用Unity3D平台,实现了碰撞区域触发和射线触发碰撞两种开门方法。%With the development of virtual reality technology,the 3D software platform has played a key role in the virtual reality.This paper mainly discusses the key technology and its realization of room simulation in virtual campuses based on Unity 3D.It includes the 3D modeling and basic operation design of the room.The 3D modeling of the room is realized by 3DMax modeling software,including the modeling of the walls,windows,doors and indoor facilities of the room.The basis operation of the room is performed on the Unity3D platform,which helps to realize the two door-opening methods:collision zone trigger and ray trigger collision.

  2. Temperature-Corrected Oxygen Detection Based on Multi-Mode Diode Laser Correlation Spectroscopy

    Directory of Open Access Journals (Sweden)

    Xiutao Lou

    2013-01-01

    Full Text Available Temperature-corrected oxygen measurements were performed by using multi-mode diode laser correlation spectroscopy at temperatures ranging between 300 and 473 K. The experiments simulate in situ monitoring of oxygen in coal-combustion exhaust gases at the tail of the flue. A linear relationship with a correlation coefficient of −0.999 was found between the evaluated concentration and the gas temperature. Temperature effects were either auto-corrected by keeping the reference gas at the same conditions as the sample gas, or rectified by using a predetermined effective temperature-correction coefficient calibrated for a range of absorption wavelengths. Relative standard deviations of the temperature-corrected oxygen concentrations obtained by different schemes and at various temperatures were estimated, yielding a measurement precision of 0.6%.

  3. Direct and Indirect Written Corrective Feedback in the Context of Genre-based Instruction on Job Application Letter Writing

    Directory of Open Access Journals (Sweden)

    Mostafa Mirzaii

    2013-10-01

    Full Text Available Despite the fact that a considerable proportion of today’s writing programs operate according to the principles of genre-based instruction, research has not adequately dealt with the teaching of various genres (e.g., job application letters. Nor has research, to date, attempted to address the issue of written corrective feedback in conjunction with genre-based instruction. This study, therefore, aimed to investigate the impact of written corrective feedback in the context of genre-based instruction on job application letters. To this end, 120 Iranian advanced-level EFL learners at Kish Institute of Science and Technology participated in the present study. After administering the TOEFL test, 80 students scoring within ±1 SD of the mean score were randomly assigned to one of two experimental groups?namely, Direct Feedback Group or Indirect Feedback Group. Having sat a writing pretest, the participants received genre-based instruction on how to compose job application letters. Meanwhile, they were supplied with direct or indirect feedback on their writing. Following this instruction, a writing posttest was administered, the results of which showed that direct corrective feedback was more effective than indirect corrective feedback in the context of genre-based instruction on letters of job application.

  4. Lessons from Evidence-Based Operating Room Management in Balancing the Needs for Efficient, Effective and Ethical Healthcare

    Science.gov (United States)

    Rosen, A.C.; Dexter, F.

    2009-01-01

    Foglia et al. (in press) describe tension in two veteran's hospitals among managers, clinicians, and patients over allocating appropriate resources to support care and inefficiencies in care delivery. Ultimately ethical healthcare in a system which is committed to caring for an entire population of patients must use its limited resources effectively while not compromising patient safety. This discussion gives examples from operating room management in which systematic analyses of existing data can guide more efficient care delivery. PMID:19326313

  5. Lessons from Evidence-Based Operating Room Management in Balancing the Needs for Efficient, Effective and Ethical Healthcare

    OpenAIRE

    Rosen, A.C.; Dexter, F.

    2009-01-01

    Foglia et al. (in press) describe tension in two veteran's hospitals among managers, clinicians, and patients over allocating appropriate resources to support care and inefficiencies in care delivery. Ultimately ethical healthcare in a system which is committed to caring for an entire population of patients must use its limited resources effectively while not compromising patient safety. This discussion gives examples from operating room management in which systematic analyses of existing dat...

  6. Research on Paradigm of Evidence-based Corrections%循证矫正的范式研究

    Institute of Scientific and Technical Information of China (English)

    侯佳

    2015-01-01

    The measures of normal correction gave rise to the anomaly and emergence under the condition of current paradigm, and there is no accomplishment of appraisal system about the validity of corrective measures. However, the invalidity of corrective measures, which resulted in amount of waste of public re-sources, is neglected for a long time. To solve these problems, there is a need to transform the paradigm of corrections. Consequently, the evidence -based corrections is produced in this anomaly and emer-gence. The evidence-based corrections obeys to the principle of best evidence in the evidence-based practices according to the brand new paradigm, purposefully implements the corrective measures on the basis of the criminogenic needs of offenders, sets up the scientific appraisal system, pays attention to the validity of corrective consequences and plays a positive role to decrease recidivism, to reduce the rate of re-committing crime, to save the cost of corrections and to prevent crime and other aspects.%常规的矫正措施在现有的范式下出现了反常和危机,对矫正措施的有效性没有建立科学的评估体系,而对于无效的矫正措施却长期被人们忽视,造成大量公共资源的浪费。为了解决上述问题,需要转换矫正的范式。因此,循证矫正在这场反常和危机中产生。循证矫正以全新的范式在循证实践中以遵循最佳证据原则,根据犯罪人的犯因性需求有针对性地实施矫正措施,并建立科学的评估体系,注重矫正结果的有效性,对于减少累犯、降低再犯率、节省矫正成本以及预防犯罪等方面发挥了积极的作用。

  7. Comparison of analytical and numerical approaches for CT-based aberration correction in transcranial passive acoustic imaging

    Science.gov (United States)

    Jones, Ryan M.; Hynynen, Kullervo

    2016-01-01

    Computed tomography (CT)-based aberration corrections are employed in transcranial ultrasound both for therapy and imaging. In this study, analytical and numerical approaches for calculating aberration corrections based on CT data were compared, with a particular focus on their application to transcranial passive imaging. Two models were investigated: a three-dimensional full-wave numerical model (Connor and Hynynen 2004 IEEE Trans. Biomed. Eng. 51 1693-706) based on the Westervelt equation, and an analytical method (Clement and Hynynen 2002 Ultrasound Med. Biol. 28 617-24) similar to that currently employed by commercial brain therapy systems. Trans-skull time delay corrections calculated from each model were applied to data acquired by a sparse hemispherical (30 cm diameter) receiver array (128 piezoceramic discs: 2.5 mm diameter, 612 kHz center frequency) passively listening through ex vivo human skullcaps (n  =  4) to emissions from a narrow-band, fixed source emitter (1 mm diameter, 516 kHz center frequency). Measurements were taken at various locations within the cranial cavity by moving the source around the field using a three-axis positioning system. Images generated through passive beamforming using CT-based skull corrections were compared with those obtained through an invasive source-based approach, as well as images formed without skull corrections, using the main lobe volume, positional shift, peak sidelobe ratio, and image signal-to-noise ratio as metrics for image quality. For each CT-based model, corrections achieved by allowing for heterogeneous skull acoustical parameters in simulation outperformed the corresponding case where homogeneous parameters were assumed. Of the CT-based methods investigated, the full-wave model provided the best imaging results at the cost of computational complexity. These results highlight the importance of accurately modeling trans-skull propagation when calculating CT-based aberration corrections

  8. [Errors Analysis and Correction in Atmospheric Methane Retrieval Based on Greenhouse Gases Observing Satellite Data].

    Science.gov (United States)

    Bu, Ting-ting; Wang, Xian-hua; Ye, Han-han; Jiang, Xin-hua

    2016-01-01

    High precision retrieval of atmospheric CH4 is influenced by a variety of factors. The uncertainties of ground properties and atmospheric conditions are important factors, such as surface reflectance, temperature profile, humidity profile and pressure profile. Surface reflectance is affected by many factors so that it is difficult to get the precise value. The uncertainty of surface reflectance will cause large error to retrieval result. The uncertainties of temperature profile, humidity profile and pressure profile are also important sources of retrieval error and they will cause unavoidable systematic error. This error is hard to eliminate only using CH4 band. In this paper, ratio spectrometry method and CO2 band correction method are proposed to reduce the error caused by these factors. Ratio spectrometry method can decrease the effect of surface reflectance in CH4 retrieval by converting absolute radiance spectrometry into ratio spectrometry. CO2 band correction method converts column amounts of CH4 into column averaged mixing ratio by using CO2 1.61 μm band and it can correct the systematic error caused by temperature profile, humidity profile and pressure profile. The combination of these two correction methods will decrease the effect caused by surface reflectance, temperature profile, humidity profile and pressure profile at the same time and reduce the retrieval error. GOSAT data were used to retrieve atmospheric CH4 to test and validate the two correction methods. The results showed that CH4 column averaged mixing ratio retrieved after correction was close to GOSAT Level2 product and the retrieval precision was up to -0.24%. The studies suggest that the error of CH4 retrieval caused by the uncertainties of ground properties and atmospheric conditions can be significantly reduced and the retrieval precision can be highly improved by using ratio spectrometry method and CO2 hand correction method. PMID:27228765

  9. [Errors Analysis and Correction in Atmospheric Methane Retrieval Based on Greenhouse Gases Observing Satellite Data].

    Science.gov (United States)

    Bu, Ting-ting; Wang, Xian-hua; Ye, Han-han; Jiang, Xin-hua

    2016-01-01

    High precision retrieval of atmospheric CH4 is influenced by a variety of factors. The uncertainties of ground properties and atmospheric conditions are important factors, such as surface reflectance, temperature profile, humidity profile and pressure profile. Surface reflectance is affected by many factors so that it is difficult to get the precise value. The uncertainty of surface reflectance will cause large error to retrieval result. The uncertainties of temperature profile, humidity profile and pressure profile are also important sources of retrieval error and they will cause unavoidable systematic error. This error is hard to eliminate only using CH4 band. In this paper, ratio spectrometry method and CO2 band correction method are proposed to reduce the error caused by these factors. Ratio spectrometry method can decrease the effect of surface reflectance in CH4 retrieval by converting absolute radiance spectrometry into ratio spectrometry. CO2 band correction method converts column amounts of CH4 into column averaged mixing ratio by using CO2 1.61 μm band and it can correct the systematic error caused by temperature profile, humidity profile and pressure profile. The combination of these two correction methods will decrease the effect caused by surface reflectance, temperature profile, humidity profile and pressure profile at the same time and reduce the retrieval error. GOSAT data were used to retrieve atmospheric CH4 to test and validate the two correction methods. The results showed that CH4 column averaged mixing ratio retrieved after correction was close to GOSAT Level2 product and the retrieval precision was up to -0.24%. The studies suggest that the error of CH4 retrieval caused by the uncertainties of ground properties and atmospheric conditions can be significantly reduced and the retrieval precision can be highly improved by using ratio spectrometry method and CO2 hand correction method.

  10. Soils Project Risk-Based Corrective Action Evaluation Process with ROTC 1 and ROTC 2, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Patrick; Sloop, Christina

    2012-04-01

    This document formally defines and clarifies the NDEP-approved process the NNSA/NSO Soils Activity uses to fulfill the requirements of the FFACO and state regulations. This process is used to establish FALs in accordance with the risk-based corrective action (RBCA) process stipulated in Chapter 445 of the Nevada Administrative Code (NAC) as described in the ASTM International (ASTM) Method E1739-95 (NAC, 2008; ASTM, 1995). It is designed to provide a set of consistent standards for chemical and radiological corrective actions.

  11. Correction of Thermal Deviations of Fabry-Perot Resonator Based Measurements of Specific Gases in Millimeter Wave Bands

    Directory of Open Access Journals (Sweden)

    J. Libich

    2012-04-01

    Full Text Available Due to the thermal expansivity of the material used in the Fabry-Perot resonator mirrors, the resonator cavity length can change and this might therefore have an impact on the resonant frequency during high-resolution spectroscopy measurements. Based on measurements and simulations, this paper discusses the influences of temperature on the precise determination of gas attenuation measured in a Fabry-Perot resonator. Several measures to mitigate such influence and to correct the measured results were tested. A correction method for the measured data was proposed.

  12. Distributed computer room monitoring system based on OPC XML DA specification%基于OPCXMLDA规范的分布式机房监控系统设计

    Institute of Scientific and Technical Information of China (English)

    丁健生

    2011-01-01

    基于OPCXMLDA规范设计了一种分布式机房监控系统,通过OPCXMLDA服务器将机房内所有监控设备采集到的数据以标准的WebService接口发布,为各种应用系统提供统一的开放式数据源,从而实现Internet、wap、短信及Windows客户端等多种途径的监控。实践表明,文中设计的系统能有效提高开发效率,易于扩展。%A distributed computer room monitoring system based on OPC XML DA specification is given in the paper. Through OPC XML DA server, the data collected from all monitors in the computer room are distributed in standard Web Service interface for offering the

  13. A neural network-based method for spectral distortion correction in photon counting x-ray CT

    Science.gov (United States)

    Touch, Mengheng; Clark, Darin P.; Barber, William; Badea, Cristian T.

    2016-08-01

    Spectral CT using a photon counting x-ray detector (PCXD) shows great potential for measuring material composition based on energy dependent x-ray attenuation. Spectral CT is especially suited for imaging with K-edge contrast agents to address the otherwise limited contrast in soft tissues. We have developed a micro-CT system based on a PCXD. This system enables both 4 energy bins acquisition, as well as full-spectrum mode in which the energy thresholds of the PCXD are swept to sample the full energy spectrum for each detector element and projection angle. Measurements provided by the PCXD, however, are distorted due to undesirable physical effects in the detector and can be very noisy due to photon starvation in narrow energy bins. To address spectral distortions, we propose and demonstrate a novel artificial neural network (ANN)-based spectral distortion correction mechanism, which learns to undo the distortion in spectral CT, resulting in improved material decomposition accuracy. To address noise, post-reconstruction denoising based on bilateral filtration, which jointly enforces intensity gradient sparsity between spectral samples, is used to further improve the robustness of ANN training and material decomposition accuracy. Our ANN-based distortion correction method is calibrated using 3D-printed phantoms and a model of our spectral CT system. To enable realistic simulations and validation of our method, we first modeled the spectral distortions using experimental data acquired from 109Cd and 133Ba radioactive sources measured with our PCXD. Next, we trained an ANN to learn the relationship between the distorted spectral CT projections and the ideal, distortion-free projections in a calibration step. This required knowledge of the ground truth, distortion-free spectral CT projections, which were obtained by simulating a spectral CT scan of the digital version of a 3D-printed phantom. Once the training was completed, the trained ANN was used to perform

  14. A neural network-based method for spectral distortion correction in photon counting x-ray CT

    Science.gov (United States)

    Touch, Mengheng; Clark, Darin P.; Barber, William; Badea, Cristian T.

    2016-08-01

    Spectral CT using a photon counting x-ray detector (PCXD) shows great potential for measuring material composition based on energy dependent x-ray attenuation. Spectral CT is especially suited for imaging with K-edge contrast agents to address the otherwise limited contrast in soft tissues. We have developed a micro-CT system based on a PCXD. This system enables both 4 energy bins acquisition, as well as full-spectrum mode in which the energy thresholds of the PCXD are swept to sample the full energy spectrum for each detector element and projection angle. Measurements provided by the PCXD, however, are distorted due to undesirable physical effects in the detector and can be very noisy due to photon starvation in narrow energy bins. To address spectral distortions, we propose and demonstrate a novel artificial neural network (ANN)-based spectral distortion correction mechanism, which learns to undo the distortion in spectral CT, resulting in improved material decomposition accuracy. To address noise, post-reconstruction denoising based on bilateral filtration, which jointly enforces intensity gradient sparsity between spectral samples, is used to further improve the robustness of ANN training and material decomposition accuracy. Our ANN-based distortion correction method is calibrated using 3D-printed phantoms and a model of our spectral CT system. To enable realistic simulations and validation of our method, we first modeled the spectral distortions using experimental data acquired from 109Cd and 133Ba radioactive sources measured with our PCXD. Next, we trained an ANN to learn the relationship between the distorted spectral CT projections and the ideal, distortion-free projections in a calibration step. This required knowledge of the ground truth, distortion-free spectral CT projections, which were obtained by simulating a spectral CT scan of the digital version of a 3D-printed phantom. Once the training was completed, the trained ANN was used to perform

  15. A neural network-based method for spectral distortion correction in photon counting x-ray CT.

    Science.gov (United States)

    Touch, Mengheng; Clark, Darin P; Barber, William; Badea, Cristian T

    2016-08-21

    Spectral CT using a photon counting x-ray detector (PCXD) shows great potential for measuring material composition based on energy dependent x-ray attenuation. Spectral CT is especially suited for imaging with K-edge contrast agents to address the otherwise limited contrast in soft tissues. We have developed a micro-CT system based on a PCXD. This system enables both 4 energy bins acquisition, as well as full-spectrum mode in which the energy thresholds of the PCXD are swept to sample the full energy spectrum for each detector element and projection angle. Measurements provided by the PCXD, however, are distorted due to undesirable physical effects in the detector and can be very noisy due to photon starvation in narrow energy bins. To address spectral distortions, we propose and demonstrate a novel artificial neural network (ANN)-based spectral distortion correction mechanism, which learns to undo the distortion in spectral CT, resulting in improved material decomposition accuracy. To address noise, post-reconstruction denoising based on bilateral filtration, which jointly enforces intensity gradient sparsity between spectral samples, is used to further improve the robustness of ANN training and material decomposition accuracy. Our ANN-based distortion correction method is calibrated using 3D-printed phantoms and a model of our spectral CT system. To enable realistic simulations and validation of our method, we first modeled the spectral distortions using experimental data acquired from (109)Cd and (133)Ba radioactive sources measured with our PCXD. Next, we trained an ANN to learn the relationship between the distorted spectral CT projections and the ideal, distortion-free projections in a calibration step. This required knowledge of the ground truth, distortion-free spectral CT projections, which were obtained by simulating a spectral CT scan of the digital version of a 3D-printed phantom. Once the training was completed, the trained ANN was used to perform

  16. Geo-correction Algorithm Based on Equivalent RD Model for ScanSAR of HJ-1-C Satellite

    Directory of Open Access Journals (Sweden)

    Liu Jia-yin

    2014-06-01

    Full Text Available HJ-1-C satellite is the first Synthetic Aperture Radar (SAR satellite for civilian use in China, and it has a strip and scan mode. According to the characteristics of the ScanSAR of the HJ-1-C satellite, a geo-correction algorithm based on an equivalent RD model has been outlined in this paper on the basis of an ECS image processing algorithm and a traditional Range-Doppler location method. An azimuth mosaic was presented by a time series relationship, then the different burst was stitched by range, and the equivalent parameters were fitted to locations on the RD model. Finally, the ScanSAR image was geo-corrected. The HJ-1-C satellite data results showed that the location accuracy of ScanSAR for the HJ-1-C satellite was less than 100 m, and the geo-correction algorithm was realized in 10 s in fewer than 24 parallel cores.

  17. A Fixed-Pattern Noise Correction Method Based on Gray Value Compensation for TDI CMOS Image Sensor.

    Science.gov (United States)

    Liu, Zhenwang; Xu, Jiangtao; Wang, Xinlei; Nie, Kaiming; Jin, Weimin

    2015-01-01

    In order to eliminate the fixed-pattern noise (FPN) in the output image of time-delay-integration CMOS image sensor (TDI-CIS), a FPN correction method based on gray value compensation is proposed. One hundred images are first captured under uniform illumination. Then, row FPN (RFPN) and column FPN (CFPN) are estimated based on the row-mean vector and column-mean vector of all collected images, respectively. Finally, RFPN are corrected by adding the estimated RFPN gray value to the original gray values of pixels in the corresponding row, and CFPN are corrected by subtracting the estimated CFPN gray value from the original gray values of pixels in the corresponding column. Experimental results based on a 128-stage TDI-CIS show that, after correcting the FPN in the image captured under uniform illumination with the proposed method, the standard-deviation of row-mean vector decreases from 5.6798 to 0.4214 LSB, and the standard-deviation of column-mean vector decreases from 15.2080 to 13.4623 LSB. Both kinds of FPN in the real images captured by TDI-CIS are eliminated effectively with the proposed method.

  18. A Fixed-Pattern Noise Correction Method Based on Gray Value Compensation for TDI CMOS Image Sensor

    Directory of Open Access Journals (Sweden)

    Zhenwang Liu

    2015-09-01

    Full Text Available In order to eliminate the fixed-pattern noise (FPN in the output image of time-delay-integration CMOS image sensor (TDI-CIS, a FPN correction method based on gray value compensation is proposed. One hundred images are first captured under uniform illumination. Then, row FPN (RFPN and column FPN (CFPN are estimated based on the row-mean vector and column-mean vector of all collected images, respectively. Finally, RFPN are corrected by adding the estimated RFPN gray value to the original gray values of pixels in the corresponding row, and CFPN are corrected by subtracting the estimated CFPN gray value from the original gray values of pixels in the corresponding column. Experimental results based on a 128-stage TDI-CIS show that, after correcting the FPN in the image captured under uniform illumination with the proposed method, the standard-deviation of row-mean vector decreases from 5.6798 to 0.4214 LSB, and the standard-deviation of column-mean vector decreases from 15.2080 to 13.4623 LSB. Both kinds of FPN in the real images captured by TDI-CIS are eliminated effectively with the proposed method.

  19. A Fixed-Pattern Noise Correction Method Based on Gray Value Compensation for TDI CMOS Image Sensor.

    Science.gov (United States)

    Liu, Zhenwang; Xu, Jiangtao; Wang, Xinlei; Nie, Kaiming; Jin, Weimin

    2015-01-01

    In order to eliminate the fixed-pattern noise (FPN) in the output image of time-delay-integration CMOS image sensor (TDI-CIS), a FPN correction method based on gray value compensation is proposed. One hundred images are first captured under uniform illumination. Then, row FPN (RFPN) and column FPN (CFPN) are estimated based on the row-mean vector and column-mean vector of all collected images, respectively. Finally, RFPN are corrected by adding the estimated RFPN gray value to the original gray values of pixels in the corresponding row, and CFPN are corrected by subtracting the estimated CFPN gray value from the original gray values of pixels in the corresponding column. Experimental results based on a 128-stage TDI-CIS show that, after correcting the FPN in the image captured under uniform illumination with the proposed method, the standard-deviation of row-mean vector decreases from 5.6798 to 0.4214 LSB, and the standard-deviation of column-mean vector decreases from 15.2080 to 13.4623 LSB. Both kinds of FPN in the real images captured by TDI-CIS are eliminated effectively with the proposed method. PMID:26389917

  20. Five-wave-packet quantum error correction based on continuous-variable cluster entanglement

    Science.gov (United States)

    Hao, Shuhong; Su, Xiaolong; Tian, Caixing; Xie, Changde; Peng, Kunchi

    2015-10-01

    Quantum error correction protects the quantum state against noise and decoherence in quantum communication and quantum computation, which enables one to perform fault-torrent quantum information processing. We experimentally demonstrate a quantum error correction scheme with a five-wave-packet code against a single stochastic error, the original theoretical model of which was firstly proposed by S. L. Braunstein and T. A. Walker. Five submodes of a continuous variable cluster entangled state of light are used for five encoding channels. Especially, in our encoding scheme the information of the input state is only distributed on three of the five channels and thus any error appearing in the remained two channels never affects the output state, i.e. the output quantum state is immune from the error in the two channels. The stochastic error on a single channel is corrected for both vacuum and squeezed input states and the achieved fidelities of the output states are beyond the corresponding classical limit.

  1. QR Code Image Correction based on Corner Detection and Convex Hull Algorithm

    Directory of Open Access Journals (Sweden)

    Suran Kong

    2013-12-01

    Full Text Available Since the angular deviation produced when shooting a QR code image by a camera would cause geometric distortion of the QR code image, the traditional algorithm of QR code image correction would produce distortion. Therefore this paper puts forward the algorithm which combines corner detection with convex hull algorithm. Firstly, binaryzation of the collected QR code image with uneven light is obtained by the methods of local threshold and mathematical morphology. Next, the outline of the QR code and the dots on it are found and the distorted image is recovered by perspective collineation, according to the algorithm raised by this paper. Finally, experimental verification is made that the algorithm raised by this paper can correctly find the four apexes of QR code and achieves good effects of geometric correction. It will also significantly increase the recognition rate of seriously distorted QR code images

  2. Force-reflecting teleoperation of robots based on on-line correction of a virtual model

    Institute of Scientific and Technical Information of China (English)

    LIU Wei; SONG Aiguo; LI Huijun

    2007-01-01

    Virtual reality is an effective method to eliminate the influence of time delay.However,it depends on the precision of the virtual model.In this paper,we introduce a method that corrects the virtual model on-line to establish a more precise model.The geometric errors of the virtual model were corrected on-line by overlapping the graphics over the images and also by syncretizing the position and force information from the remote.Then the sliding average least squares (SALS)method was adopted to determine the mass,damp,and stiffness of the remote environment and use this information to amend the dynamic model of the environment.Experimental results demonstrate that the on-line correction method we proposed can effectively reduce the impact caused by time delay,and improve the operational performance of the teleoperation system.

  3. Dixon sequence with superimposed model-based bone compartment provides highly accurate PET/MR attenuation correction of the brain

    OpenAIRE

    Koesters, Thomas; Friedman, Kent P.; Fenchel, Matthias; Zhan, Yiqiang; Hermosillo, Gerardo; Babb, James; Jelescu, Ileana O.; Faul, David; Boada, Fernando E.; Shepherd, Timothy M.

    2016-01-01

    Simultaneous PET/MR of the brain is a promising new technology for characterizing patients with suspected cognitive impairment or epilepsy. Unlike CT though, MR signal intensities do not provide a direct correlate to PET photon attenuation correction (AC) and inaccurate radiotracer standard uptake value (SUV) estimation could limit future PET/MR clinical applications. We tested a novel AC method that supplements standard Dixon-based tissue segmentation with a superimposed model-based bone com...

  4. Visual-based simultaneous localization and mapping and global positioning system correction for geo-localization of a mobile robot

    OpenAIRE

    Berrabah, Sid Ahmed; Sahli, Hichem; Baudoin, Yvan

    2011-01-01

    This paper introduces an approach combining visual-based simultaneous localization and mapping (V-SLAM) and global positioning system (GPS) correction for accurate multi-sensor localization of an outdoor mobile robot in geo-referenced maps. The proposed framework combines two extended Kalman filters (EKF); the first one, referred to as the integration filter, is dedicated to the improvement of the GPS localization based on data from an inertial navigation system and wheels’ encode...

  5. An Enhanced MWR-Based Wet Tropospheric Correction for Sentinel-3: Inheritance from Past ESA Altimetry Missions

    Science.gov (United States)

    Lazaro, Clara; Fernandes, Joanna M.

    2015-12-01

    The GNSS-derived Path Delay (GPD) and the Data Combination (DComb) algorithms were developed by University of Porto (U.Porto), in the scope of different projects funded by ESA, to compute a continuous and improved wet tropospheric correction (WTC) for use in satellite altimetry. Both algorithms are mission independent and are based on a linear space-time objective analysis procedure that combines various wet path delay data sources. A new algorithm that gets the best of each aforementioned algorithm (GNSS-derived Path Delay Plus, GPD+) has been developed at U.Porto in the scope of SL_cci project, where the use of consistent and stable in time datasets is of major importance. The algorithm has been applied to the main eight altimetric missions (TOPEX/Poseidon, Jason-1, Jason-2, ERS-1, ERS-2, Envisat and CryoSat-2 and SARAL). Upcoming Sentinel-3 possesses a two-channel on-board radiometer similar to those that were deployed in ERS-1/2 and Envisat. Consequently, the fine-tuning of the GPD+ algorithm to these missions datasets shall enrich it, by increasing its capability to quickly deal with Sentinel-3 data. Foreseeing that the computation of an improved MWR-based WTC for use with Sentinel-3 data will be required, this study focuses on the results obtained for ERS-1/2 and Envisat missions, which are expected to give insight into the computation of this correction for the upcoming ESA altimetric mission. The various WTC corrections available for each mission (in general, the original correction derived from the on-board MWR, the model correction and the one derived from GPD+) are inter-compared either directly or using various sea level anomaly variance statistical analyses. Results show that the GPD+ algorithm is efficient in generating global and continuous datasets, corrected for land and ice contamination and spurious measurements of instrumental origin, with significant impacts on all ESA missions.

  6. Electrically Pumped Room-Temperature Pulsed InGaAsP-Si Hybrid Lasers Based on Metal Bonding

    Institute of Scientific and Technical Information of China (English)

    CHEN Ting; RAN Guang-Zhao; WANG Wei; QIN Guo-Gang; HONG Tao; PAN Jiao-Qing; CHEN Wei-Xi; CHENG Yuan-Bing; WANG Yang; MA Xiao-Bo; LIU Wei-Li; ZHAO Ling-Juan

    2009-01-01

    A pulsed InGaAsP-Si hybrid laser is fabricated using metal bonding.A novel structure in which the optical coupling and metal bonding areas are transversely separated is employed to integrate the silicon waveguide with an InGaAsP multi-quantum well distributed feedback structure.When electrically pumped at room temperature,the laser operates with a threshold current density of 2.9 kA/cm2 and a slope efficiency of 0.02 W/A.The 1542nm laser output exits mainly from the Si waveguide.

  7. Correcting Spatial Variance of RCM for GEO SAR Imaging Based on Time-Frequency Scaling.

    Science.gov (United States)

    Yu, Ze; Lin, Peng; Xiao, Peng; Kang, Lihong; Li, Chunsheng

    2016-01-01

    Compared with low-Earth orbit synthetic aperture radar (SAR), a geosynchronous (GEO) SAR can have a shorter revisit period and vaster coverage. However, relative motion between this SAR and targets is more complicated, which makes range cell migration (RCM) spatially variant along both range and azimuth. As a result, efficient and precise imaging becomes difficult. This paper analyzes and models spatial variance for GEO SAR in the time and frequency domains. A novel algorithm for GEO SAR imaging with a resolution of 2 m in both the ground cross-range and range directions is proposed, which is composed of five steps. The first is to eliminate linear azimuth variance through the first azimuth time scaling. The second is to achieve RCM correction and range compression. The third is to correct residual azimuth variance by the second azimuth time-frequency scaling. The fourth and final steps are to accomplish azimuth focusing and correct geometric distortion. The most important innovation of this algorithm is implementation of the time-frequency scaling to correct high-order azimuth variance. As demonstrated by simulation results, this algorithm can accomplish GEO SAR imaging with good and uniform imaging quality over the entire swath. PMID:27428974

  8. Anatomically guided voxel-based partial volume effect correction in brain PET : Impact of MRI segmentation

    NARCIS (Netherlands)

    Gutierrez, Daniel; Montandon, Marie-Louise; Assal, Frederic; Allaoua, Mohamed; Ratib, Osman; Loevblad, Karl-Olof; Zaidi, Habib

    2012-01-01

    Partial volume effect is still considered one of the main limitations in brain PET imaging given the limited spatial resolution of current generation PET scanners. The accuracy of anatomically guided partial volume effect correction (PVC) algorithms in brain PET is largely dependent on the performan

  9. Correcting encoder interpolation error on the Green Bank Telescope using an iterative model based identification algorithm

    Science.gov (United States)

    Franke, Timothy; Weadon, Tim; Ford, John; Garcia-Sanz, Mario

    2015-10-01

    Various forms of measurement errors limit telescope tracking performance in practice. A new method for identifying the correcting coefficients for encoder interpolation error is developed. The algorithm corrects the encoder measurement by identifying a harmonic model of the system and using that model to compute the necessary correction parameters. The approach improves upon others by explicitly modeling the unknown dynamics of the structure and controller and by not requiring a separate system identification to be performed. Experience gained from pin-pointing the source of encoder error on the Green Bank Radio Telescope (GBT) is presented. Several tell-tale indicators of encoder error are discussed. Experimental data from the telescope, tested with two different encoders, are presented. Demonstration of the identification methodology on the GBT as well as details of its implementation are discussed. A root mean square tracking error reduction from 0.68 arc seconds to 0.21 arc sec was achieved by changing encoders and was further reduced to 0.10 arc sec with the calibration algorithm. In particular, the ubiquity of this error source is shown and how, by careful correction, it is possible to go beyond the advertised accuracy of an encoder.

  10. Model-Based Illumination Correction for Face Images in Uncontrolled Scenarios

    NARCIS (Netherlands)

    Boom, Bas; Spreeuwers, Luuk; Veldhuis, Raymond

    2009-01-01

    Face Recognition under uncontrolled illumination conditions is partly an unsolved problem. Several illumination correction methods have been proposed, but these are usually tested on illumination conditions created in a laboratory. Our focus is more on uncontrolled conditions. We use the Phong model

  11. 76 FR 39006 - Medicare Program; Hospital Inpatient Value-Based Purchasing Program; Correction

    Science.gov (United States)

    2011-07-05

    ... errors that appeared in the final rule published in the Federal Register on May 6, 2011 (76 FR 26490...) 786-2075. SUPPLEMENTARY INFORMATION: I. Background In FR Doc. 2011-10568 of May 6, 2011 (76 FR 26490.... III. Correction of Errors In FR Doc. 2011-10568 of May 6, 2011 (76 FR 26490), make the...

  12. GA-based dynamical correction of dispersion coefficients in Lagrangian puff model

    Institute of Scientific and Technical Information of China (English)

    马元巍; 王德忠; 吉志龙

    2015-01-01

    In atmospheric dispersion models of nuclear accident, the dispersion coefficients were usually obtained by tracer experiment, which are constant in different atmospheric stability classifications. In fact, the atmospheric wind field is complex and unstable. The dispersion coefficients change even in the same atmospheric stability, hence the great errors brought in. According to the regulation, the air concentration of nuclides around nuclear power plant should be monitored during an accident. The monitoring data can be used to correct dispersion coefficients dynamically. The error can be minimized by correcting the coefficients. This reverse problem is nonlinear and sensitive to initial value. The property of searching the optimal solution of Genetic Algorithm (GA) is suitable for complex high-dimensional situation. In this paper, coupling with Lagrange dispersion model, GA is used to estimate the coefficients. The simulation results show that GA scheme performs well when the error is big. When the correcting process is used in the experiment data, the GA-estimated results are numerical instable. The success rate of estimation is 5%lower than the one without correction. Taking into account the continuity of the dispersion coefficient, Savitzky-Golay filter is used to smooth the estimated parameters. The success rate of estimation increases to 75.86%. This method can improve the accuracy of atmospheric dispersion simulation.

  13. A primary standard of optical power based on induced-junction silicon photodiodes operated at room temperature

    Science.gov (United States)

    Dönsberg, Timo; Sildoja, Meelis; Manoocheri, Farshid; Merimaa, Mikko; Petroff, Leo; Ikonen, Erkki

    2014-06-01

    We present the design and construction of a new compact room temperature predictable quantum efficient detector (PQED). It consists of two custom-made induced-junction photodiodes mounted in a wedge trap configuration and a window aligned at Brewster's angle for high transmission of p polarized light. The window can also be removed, in which case a dry nitrogen flow system is utilized to prevent dust contamination of the photodiodes. Measurements of individual detectors at the wavelength of 488 nm indicate that reflectance and spectral responsivity are consistent within 4 ppm and 13 ppm peak-to-peak variation, respectively, and agree with the predicted values. The spatial non-uniformity of the responsivity of the PQED is an order of magnitude lower than that of single photodiodes. The internal quantum efficiency of the photodiodes is concluded to be spatially uniform within 50 ppm. These measurement results—together with the responsivity predictable by fundamental laws of physics—provide evidence that the room temperature PQED may replace the cryogenic radiometer as a primary standard of optical power in the visible wavelength range of 380 nm to 780 nm.

  14. Gesture-Controlled Interface for Contactless Control of Various Computer Programs with a Hooking-Based Keyboard and Mouse-Mapping Technique in the Operating Room.

    Science.gov (United States)

    Park, Ben Joonyeon; Jang, Taekjin; Choi, Jong Woo; Kim, Namkug

    2016-01-01

    We developed a contactless interface that exploits hand gestures to effectively control medical images in the operating room. We developed an in-house program called GestureHook that exploits message hooking techniques to convert gestures into specific functions. For quantitative evaluation of this program, we used gestures to control images of a dynamic biliary CT study and compared the results with those of a mouse (8.54 ± 1.77 s to 5.29 ± 1.00 s; p gestures and the success rates of tasks based on clinical scenarios. For clinical applications, this program was set up in the operating room to browse images for plastic surgery. A surgeon browsed images from three different programs: CT images from a PACS program, volume-rendered images from a 3D PACS program, and surgical planning photographs from a basic image viewing program. All programs could be seamlessly controlled by gestures and motions. This approach can control all operating room programs without source code modification and provide surgeons with a new way to safely browse through images and easily switch applications during surgical procedures. PMID:26981146

  15. Simulation-based partial volume correction for dopaminergic PET imaging. Impact of segmentation accuracy

    International Nuclear Information System (INIS)

    Partial volume correction (PVC) is an essential step for quantitative positron emission tomography (PET). In the present study, PVELab, a freely available software, is evaluated for PVC in 18F-FDOPA brain-PET, with a special focus on the accuracy degradation introduced by various MR-based segmentation approaches. Methods Four PVC algorithms (M-PVC; MG-PVC; mMG-PVC; and R-PVC) were analyzed on simulated 18F-FDOPA brain-PET images. MR image segmentation was carried out using FSL (FMRIB Software Library) and SPM (Statistical Parametric Mapping) packages, including additional adaptation for subcortical regions (SPML). Different PVC and segmentation combinations were compared with respect to deviations in regional activity values and time-activity curves (TACs) of the occipital cortex (OCC), caudate nucleus (CN), and putamen (PUT). Additionally, the PVC impact on the determination of the influx constant (Ki) was assessed. Results Main differences between tissue-maps returned by three segmentation algorithms were found in the subcortical region, especially at PUT. Average misclassification errors in combination with volume reduction was found to be lowest for SPML (PUT < 30%) and highest for FSL (PUT > 70%). Accurate recovery of activity data at OCC is achieved by M-PVC (apparent recovery coefficient varies between 0.99 and 1.10). The other three evaluated PVC algorithms have demonstrated to be more suitable for subcortical regions with MG-PVC and mMG-PVC being less prone to the largest tissue misclassification error simulated in this study. Except for M-PVC, quantification accuracy of Ki for CN and PUT was clearly improved by PVC. Conclusions The regional activity value of PUT was appreciably overcorrected by most of the PVC approaches employing FSL or SPM segmentation, revealing the importance of accurate MR image segmentation for the presented PVC framework. The selection of a PVC approach should be adapted to the anatomical structure of interest. Caution is

  16. Simulation-based partial volume correction for dopaminergic PET imaging. Impact of segmentation accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Rong, Ye; Winz, Oliver H. [University Hospital Aachen (Germany). Dept. of Nuclear Medicine; Vernaleken, Ingo [University Hospital Aachen (Germany). Dept. of Psychiatry, Psychotherapy and Psychosomatics; Goedicke, Andreas [University Hospital Aachen (Germany). Dept. of Nuclear Medicine; High Tech Campus, Philips Research Lab., Eindhoven (Netherlands); Mottaghy, Felix M. [University Hospital Aachen (Germany). Dept. of Nuclear Medicine; Maastricht University Medical Center (Netherlands). Dept. of Nuclear Medicine; Rota Kops, Elena [Forschungszentrum Juelich (Germany). Inst. of Neuroscience and Medicine-4

    2015-07-01

    Partial volume correction (PVC) is an essential step for quantitative positron emission tomography (PET). In the present study, PVELab, a freely available software, is evaluated for PVC in {sup 18}F-FDOPA brain-PET, with a special focus on the accuracy degradation introduced by various MR-based segmentation approaches. Methods Four PVC algorithms (M-PVC; MG-PVC; mMG-PVC; and R-PVC) were analyzed on simulated {sup 18}F-FDOPA brain-PET images. MR image segmentation was carried out using FSL (FMRIB Software Library) and SPM (Statistical Parametric Mapping) packages, including additional adaptation for subcortical regions (SPM{sub L}). Different PVC and segmentation combinations were compared with respect to deviations in regional activity values and time-activity curves (TACs) of the occipital cortex (OCC), caudate nucleus (CN), and putamen (PUT). Additionally, the PVC impact on the determination of the influx constant (K{sub i}) was assessed. Results Main differences between tissue-maps returned by three segmentation algorithms were found in the subcortical region, especially at PUT. Average misclassification errors in combination with volume reduction was found to be lowest for SPM{sub L} (PUT < 30%) and highest for FSL (PUT > 70%). Accurate recovery of activity data at OCC is achieved by M-PVC (apparent recovery coefficient varies between 0.99 and 1.10). The other three evaluated PVC algorithms have demonstrated to be more suitable for subcortical regions with MG-PVC and mMG-PVC being less prone to the largest tissue misclassification error simulated in this study. Except for M-PVC, quantification accuracy of K{sub i} for CN and PUT was clearly improved by PVC. Conclusions The regional activity value of PUT was appreciably overcorrected by most of the PVC approaches employing FSL or SPM segmentation, revealing the importance of accurate MR image segmentation for the presented PVC framework. The selection of a PVC approach should be adapted to the anatomical

  17. An artificial vision-based control system for automatic heliostat positioning offset correction in a central receiver solar power plant

    Energy Technology Data Exchange (ETDEWEB)

    Berenguel, M. [Universidad de Almeria, Dept. de Lenguajes y Computacion, La Canada Almeria (Spain); Rubio, F.R.; Lara, P.J.; Arahal, M.R.; Camacho, E.F.; Lopez, M. [Universidad de Sevilla, Dept. de Ingenieria de Sistemas y Automatica, Sevilla (Spain); Valverde, A. [Plataforma Solar de Almeria (PSA-CIEMAT), Tabernas (Almeria) (Spain)

    2004-07-01

    This paper presents the development of a simplified and automatic heliostat positioning offset correction control system using artificial vision techniques and common CCD devices. The heliostats of a solar power plant reflect solar radiation onto a receiver (in this case, a volumetric receiver) placed at the top of a tower in order to provide a desired energy flux distribution correlated with the coolant flow (in this case air mass flow) through the receiver, usually in an open loop control configuration. There exist error sources that increase the complexity of the control system, some of which are systematic ones, mainly due to tolerances, wrong mirror facets alignment (optical errors), errors due to the approximations made when calculating the solar position, etc., that produce errors (offsets) in the heliostat orientation (aiming point). The approximation adopted in this paper is based on the use of a B/W CCD camera to correct these deviations in an automatic way imitating the same procedure followed by the operators. The obtained images are used to estimate the distance between the sunbeam centroid projected by the heliostats and a target placed on the tower, this distance thus is used for low accuracy offset correction purposes. Basic threshold-based image processing techniques are used for automatic correction. (Author)

  18. Awareness and Attitude toward Refractive Error Correction Methods: A Population Based Study in Mashhad

    Directory of Open Access Journals (Sweden)

    Saber Moghaddam Ranjbar AK

    2013-10-01

    Full Text Available Objectives: This study was designed to determine the level of awareness and attitude toward refractive correction methods in a randomly selected population in Mashhad, Iran. Materials and Methods: A random cluster sampling method was applied to choose 193 subjects aged 12 years and above from Mashhad population. A structured questionnaire with open-ended and closed-ended questions was designed to gather the participants' demographic data such as: gender, age, educational status and occupation, as well as their awareness and attitude toward refractive correction methods (Spectacles, Contact lenses and Refractive surgery. Results:  In overall, 39% of the participants had a clear perception of 'ophthalmologist' and 'optometrist' terms. 80.3%, 87% and 71% of respondents had no information of contact lens application instead of spectacles, cosmetic contact lenses and contact lenses with both refractive correction and cosmetic properties, respectively. 82.5% of participants were not aware of the possibility of refractive surgery for improving their eyesight and decreasing their dependency on spectacles. Awareness about contact lenses and refractive surgery’s adverse effects were only 16% and 8%, respectively. Conclusion: Awareness and perception of refractive correction methods was low among the participants of this study. Although, ophthalmologists were the first source of consultation on sight impairments among respondents, a predominant percentage of subjects were not even aware of obvious differences between an ophthalmologist and an optometrist. These findings emphasize the necessity for proper public education on ophthalmic care and the available services, specially the new correction methods for improvement of quality of life.

  19. Graphene-based, mid-infrared, room-temperature pyroelectric bolometers with ultrahigh temperature coefficient of resistance

    CERN Document Server

    Sassi, U; Nanot, S; Bruna, M; Borini, S; Milana, S; De Fazio, D; Zhuang, Z; Lidorikis, E; Koppens, F H L; Ferrari, A C; Colli, A

    2016-01-01

    Graphene is ideally suited for photonic and optoelectronic applications, with a variety of photodetectors (PDs) in the visible, near-infrared (NIR), and THz reported to date, as well as thermal detectors in the mid-infrared (MIR). Here, we present a room temperature-MIR-PD where the pyroelectric response of a LiNbO3 crystal is transduced with high gain (up to 200) into resistivity modulation for graphene, leading to a temperature coefficient of resistance up to 900%/K, two orders of magnitude higher than the state of the art, for a device area of 300x300um2. This is achieved by fabricating a floating metallic structure that concentrates the charge generated by the pyroelectric substrate on the top-gate capacitor of the graphene channel. This allows us to resolve temperature variations down to 15umK at 1 Hz, paving the way for a new generation of detectors for MIR imaging and spectroscopy

  20. Millimeter-band oscillations based on resonant tunneling in a double-barrier diode at room temperature

    Science.gov (United States)

    Brown, E. R.; Sollner, T. C. L. G.; Goodhue, W. D.; Parker, C. D.

    1987-01-01

    A double-barrier diode at room temperature has yielded oscillations with fundamental frequencies up to 56 GHz and second harmonics up to 87 GHz. The output powers at these frequencies were about 60 and 18 microW, respectively. These results are attributed to a recent improvement in the material parameters of the device and to the integration of the device into a waveguide resonator. The most successful diode to date has thin (about 1.5 nm) AlAs barriers, a 4.5-nm-wide GaAs quantum well, and 2 x 10 to the 17th/cu cm doping concentration in the n-GaAs outside the barriers. This particular diode is expected to oscillate at frequencies higher than those achieved by any reported p-n tunnel diode.

  1. Mapping hydrological environments in central Amazonia: ground validation and surface model based on SRTM DEM data corrected for deforestation

    Directory of Open Access Journals (Sweden)

    G. M. Moulatlet

    2014-07-01

    Full Text Available One of the most important freely available digital elevation models (DEMs for Amazonia is the one obtained by the Shuttle Radar Topography Mission (SRTM. However, since SRTM tends to represent the vegetation surface instead of the ground surface, the broad use of SRTM DEM as a framework for terrain description in Amazonia is hampered by the presence of deforested areas. We present here two datasets: (1 a deforestation-corrected SRTM DEM for the interfluve between the Purus and Madeira rivers, in central Amazonia, which passed through a careful identification of different environments and has deforestation features corrected by a new method of increasing pixel values of the DEM; and (2 a set of eighteen hydrological-topographic descriptors based on the corrected SRTM DEM. The hydrological-topographic description was generated by the Height Above the Nearest Drainage (HAND algorithm, which normalizes the terrain elevation (a.s.l. by the elevation of the nearest hydrologically connected drainage. The validation of the HAND dataset was done by in situ hydrological description of 110 km of walking trails also available in this dataset. The new SRTM DEM expands the applicability of SRTM data for landscape modelling; and the datasets of hydrological features based on topographic modelling is undoubtedly appropriate for ecological modelling and an important contribution for environmental mapping of Amazonia. The deforestation-corrected SRTM DEM is available at http://ppbio.inpa.gov.br/knb/metacat/naman.318.3/ppbio; the polygons selected for deforestation correction are available at http://ppbio.inpa.gov.br/knb/metacat/naman.317.3/ppbio; the set of hydrological-topographic descriptors is available at http://ppbio.inpa.gov.br/knb/metacat/naman.544.2/ppbio; and the environmental description of access trails is available at http://ppbio.inpa.gov.br/knb/metacat/naman.541.2/ppbio.

  2. A Model-Based Scatter Artifacts Correction for Cone Beam CT

    CERN Document Server

    Zhao, Wei; Zhu, Jun; Wang, Luyao; Xing, Lei

    2016-01-01

    The purpose of this work is to provide a fast and accurate scatter artifacts correction algorithm for cone beam CT (CBCT) imaging. The method starts with an estimation of coarse scatter profiles for a set of CBCT data in either image domain or projection domain. A denoising algorithm designed specifically for Poisson signals is then applied to derive the final scatter distribution. Qualitative and quantitative evaluations using thorax and abdomen phantoms with Monte Carlo (MC) simulations, experimental Catphan phantom data, and in vivo human data acquired for a clinical image guided radiation therapy were performed. Results show that the proposed algorithm can significantly reduce scatter artifacts and recover the correct HU in either projection domain or image domain. For the MC thorax phantom study, four components segmentation yield the best results, while the results of three components segmentation are still acceptable. For the Catphan phantom data, the mean value over all pixels in the residual image is...

  3. A Facile pH Controlled Citrate-Based Reduction Method for Gold Nanoparticle Synthesis at Room Temperature.

    Science.gov (United States)

    Tyagi, Himanshu; Kushwaha, Ajay; Kumar, Anshuman; Aslam, Mohammed

    2016-12-01

    The synthesis of gold nanoparticles using citrate reduction process has been revisited. A simplified room temperature approach to standard Turkevich synthesis is employed to obtain fairly monodisperse gold nanoparticles. The role of initial pH alongside the concentration ratio of reactants is explored for the size control of Au nanoparticles. The particle size distribution has been investigated using UV-vis spectroscopy and transmission electron microscope (TEM). At optimal pH of 5, gold nanoparticles obtained are highly monodisperse and spherical in shape and have narrower size distribution (sharp surface plasmon at 520 nm). For other pH conditions, particles are non-uniform and polydisperse, showing a red-shift in plasmon peak due to aggregation and large particle size distribution. The room temperature approach results in highly stable "colloidal" suspension of gold nanoparticles. The stability test through absorption spectroscopy indicates no sign of aggregation for a month. The rate of reduction of auric ionic species by citrate ions is determined via UV absorbance studies. The size of nanoparticles under various conditions is thus predicted using a theoretical model that incorporates nucleation, growth, and aggregation processes. The faster rate of reduction yields better size distribution for optimized pH and reactant concentrations. The model involves solving population balance equation for continuously evolving particle size distribution by discretization techniques. The particle sizes estimated from the simulations (13 to 25 nm) are close to the experimental ones (10 to 32 nm) and corroborate the similarity of reaction processes at 300 and 373 K (classical Turkevich reaction). Thus, substitution of experimentally measured rate of disappearance of auric ionic species into theoretical model enables us to capture the unusual experimental observations. PMID:27526178

  4. A Facile pH Controlled Citrate-Based Reduction Method for Gold Nanoparticle Synthesis at Room Temperature

    Science.gov (United States)

    Tyagi, Himanshu; Kushwaha, Ajay; Kumar, Anshuman; Aslam, Mohammed

    2016-08-01

    The synthesis of gold nanoparticles using citrate reduction process has been revisited. A simplified room temperature approach to standard Turkevich synthesis is employed to obtain fairly monodisperse gold nanoparticles. The role of initial pH alongside the concentration ratio of reactants is explored for the size control of Au nanoparticles. The particle size distribution has been investigated using UV-vis spectroscopy and transmission electron microscope (TEM). At optimal pH of 5, gold nanoparticles obtained are highly monodisperse and spherical in shape and have narrower size distribution (sharp surface plasmon at 520 nm). For other pH conditions, particles are non-uniform and polydisperse, showing a red-shift in plasmon peak due to aggregation and large particle size distribution. The room temperature approach results in highly stable "colloidal" suspension of gold nanoparticles. The stability test through absorption spectroscopy indicates no sign of aggregation for a month. The rate of reduction of auric ionic species by citrate ions is determined via UV absorbance studies. The size of nanoparticles under various conditions is thus predicted using a theoretical model that incorporates nucleation, growth, and aggregation processes. The faster rate of reduction yields better size distribution for optimized pH and reactant concentrations. The model involves solving population balance equation for continuously evolving particle size distribution by discretization techniques. The particle sizes estimated from the simulations (13 to 25 nm) are close to the experimental ones (10 to 32 nm) and corroborate the similarity of reaction processes at 300 and 373 K (classical Turkevich reaction). Thus, substitution of experimentally measured rate of disappearance of auric ionic species into theoretical model enables us to capture the unusual experimental observations.

  5. Application of system-based correction factors in condition rating of steel-composite bridges

    OpenAIRE

    Casas Rius, Joan Ramon; Anitori, Giorgio; ghosn, michel

    2016-01-01

    Traditional condition rating procedures concentrate on member condition and give no consider-ation to system behavior. In this paper a methodology is proposed to modify the correction factor applied dur-ing the assignment of bridge condition rating to account for bridge system behavior. Robustness and redun-dancy concepts that have been used in the past for structural design of new bridges and for assessment of existing bridges are in this work extended to condition rating, which represents t...

  6. The Simulation and Correction to the Brain Deformation Based on the Linear Elastic Model in IGS

    Institute of Scientific and Technical Information of China (English)

    MUXiao-lan; SONGZhi-jian

    2004-01-01

    The brain deformation is a vital factor affecting the precision of the IGS and it becomes a hotspot to simulate and correct the brain deformation recently.The research organizations, which firstly resolved the brain deformation with the physical models, have the Image Processing and Analysis department of Yale University, Biomedical Modeling Lab of Vanderbilt University and so on. The former uses the linear elastic model; the latter uses the consolidation model.

  7. QR Code Image Correction based on Corner Detection and Convex Hull Algorithm

    OpenAIRE

    Suran Kong

    2013-01-01

    Since the angular deviation produced when shooting a QR code image by a camera would cause geometric distortion of the QR code image, the traditional algorithm of QR code image correction would produce distortion. Therefore this paper puts forward the algorithm which combines corner detection with convex hull algorithm. Firstly, binaryzation of the collected QR code image with uneven light is obtained by the methods of local threshold and mathematical morphology. Next, the outline of the QR c...

  8. A Method for Multiplex Gene Synthesis Employing Error Correction Based on Expression

    OpenAIRE

    Timothy H-C Hsiau; David Sukovich; Phillip Elms; Prince, Robin N.; Tobias Strittmatter; Paul Ruan; Bo Curry; Paige Anderson; Jeff Sampson; J Christopher Anderson

    2015-01-01

    Our ability to engineer organisms with new biosynthetic pathways and genetic circuits is limited by the availability of protein characterization data and the cost of synthetic DNA. With new tools for reading and writing DNA, there are opportunities for scalable assays that more efficiently and cost effectively mine for biochemical protein characteristics. To that end, we have developed the Multiplex Library Synthesis and Expression Correction (MuLSEC) method for rapid assembly, error correcti...

  9. Awareness and Attitude toward Refractive Error Correction Methods: A Population Based Study in Mashhad

    OpenAIRE

    Saber Moghaddam Ranjbar AK; Pourmazar R; Gohary I

    2013-01-01

    Objectives: This study was designed to determine the level of awareness and attitude toward refractive correction methods in a randomly selected population in Mashhad, Iran. Materials and Methods: A random cluster sampling method was applied to choose 193 subjects aged 12 years and above from Mashhad population. A structured questionnaire with open-ended and closed-ended questions was designed to gather the participants' demographic data such as: gender, age, educational status and occupation...

  10. RighTime: A real time clock correcting program for MS-DOS-based computer systems

    Science.gov (United States)

    Becker, G. Thomas

    1993-01-01

    A computer program is described which effectively eliminates the misgivings of the DOS system clock in PC/AT-class computers. RighTime is a small, sophisticated memory-resident program that automatically corrects both the DOS system clock and the hardware 'CMOS' real time clock (RTC) in real time. RighTime learns what corrections are required without operator interaction beyond the occasional accurate time set. Both warm (power on) and cool (power off) errors are corrected, usually yielding better than one part per million accuracy in the typical desktop computer with no additional hardware, and RighTime increases the system clock resolution from approximately 0.0549 second to 0.01 second. Program tools are also available which allow visualization of RighTime's actions, verification of its performance, display of its history log, and which provide data for graphing of the system clock behavior. The program has found application in a wide variety of industries, including astronomy, satellite tracking, communications, broadcasting, transportation, public utilities, manufacturing, medicine, and the military.

  11. Ionospheric correction for spaceborne single-frequency GPS based on single layer model

    Indian Academy of Sciences (India)

    Xia Yang; Jiancheng Li; Shoujian Zhang

    2014-06-01

    A modified ionospheric correction method and the corresponding approximate algorithm for spaceborne single-frequency Global Positioning System (GPS) users are proposed in this study. Single Layer Model (SLM) mapping function for spaceborne GPS was analyzed. SLM mapping functions at different altitudes were calculated. Ionospheric Pierce Point (IPP) trajectories of the dlft station (an IGS station located at the longitude of 4° 23′ 15.22′′E and the latitude of 51° 59′ 9.63′′N, in the TU Delft University, The Netherlands) and the GRACE satellite were computed with the corresponding single layer height of 350 and 500 km, respectively. The Klobuchar model was used to compute ionospheric delays for the dlft station, and modified Klobuchar model, together with scale factors, was used to compute the fractional ionospheric corrections above the GRACE altitudes. Calculation results were validated using dual-frequency observations. The study shows that the single layer height needs to be changed from 350 to 500 km according to the altitude of GRACE. Approximate forms of Earth angle and slant factor developed for modified Klobuchar model are applicable to GRACE, with accuracy adequate to preserve the essential elements required to compute ionospheric delays. Results show that the Klobuchar model is effective for ground GPS, and the modified Klobuchar model corrects more than 80% on average of the ionospheric delays for spaceborne single-frequency GPS.

  12. Evaluation of model-based deformation correction in image-guided liver surgery via tracked intraoperative ultrasound.

    Science.gov (United States)

    Clements, Logan W; Collins, Jarrod A; Weis, Jared A; Simpson, Amber L; Adams, Lauryn B; Jarnagin, William R; Miga, Michael I

    2016-01-01

    Soft-tissue deformation represents a significant error source in current surgical navigation systems used for open hepatic procedures. While numerous algorithms have been proposed to rectify the tissue deformation that is encountered during open liver surgery, clinical validation of the proposed methods has been limited to surface-based metrics, and subsurface validation has largely been performed via phantom experiments. The proposed method involves the analysis of two deformation-correction algorithms for open hepatic image-guided surgery systems via subsurface targets digitized with tracked intraoperative ultrasound (iUS). Intraoperative surface digitizations were acquired via a laser range scanner and an optically tracked stylus for the purposes of computing the physical-to-image space registration and for use in retrospective deformation-correction algorithms. Upon completion of surface digitization, the organ was interrogated with a tracked iUS transducer where the iUS images and corresponding tracked locations were recorded. Mean closest-point distances between the feature contours delineated in the iUS images and corresponding three-dimensional anatomical model generated from preoperative tomograms were computed to quantify the extent to which the deformation-correction algorithms improved registration accuracy. The results for six patients, including eight anatomical targets, indicate that deformation correction can facilitate reduction in target error of [Formula: see text]. PMID:27081664

  13. An effective scatter correction method based on single scatter simulation for a 3D whole-body PET scanner

    Institute of Scientific and Technical Information of China (English)

    Gao Fei; Yamada Ryoko; Watanabe Mitsuo; Liu Hua-Feng

    2009-01-01

    Hamamatsu SHR74000 is a newly designed full three-dimensional(3D)whole body positron emission tomography (PET)scanner with small crystal size and large field of view(FOV).With the improvement of sensitivity,the scatter events increase significantly at the same time,especially for large objects.Monte Carlo simulations help US to understand the scatter phenomena and provide good references for scatter correction.In this paper,we introduce an effective scatter correction method based on single scatter simulation for the new PET scanner,which accounts for the full 3D scatter correction.With the results from Monte Carlo simulations,we implement a new scale method with special concentration on scatter events from outside the axial FOV and multiple scatter events.The effects of scatter correction are investigated and evaluated by phantom experiments;the results show good improvements in quantitative accuracy and contrast of the images,even for large objects.

  14. Excited States of DNA Base Pairs Using Long-Range Corrected Time-Dependent Density Functional Theory

    Science.gov (United States)

    Jensen, Lasse; Govind, Niranjan

    2009-08-01

    In this work, we present a study of the excitation energies of adenine, cytosine, guanine, thymine, and the adenine-thymine (AT) and guanine-cytosine (GC) base pairs using long-range corrected (LC) density functional theory. We compare three recent LC functionals, BNL, CAM-B3LYP, and LC-PBE0, with B3LYP and coupled cluster results from the literature. We find that the best overall performance is for the BNL functional based on LDA. However, in order to achieve this good agreement, a smaller attenuation parameter is needed, which leads to nonoptimum performance for ground-state properties. B3LYP, on the other hand, severely underestimates the charge-transfer (CT) transitions in the base pairs. Surprisingly, we also find that the CAM-B3LYP functional also underestimates the CT excitation energy for the GC base pair but correctly describes the AT base pair. This illustrates the importance of retaining the full long-range exact exchange even at distances as short as that of the DNA base pairs. The worst overall performance is obtained with the LC-PBE0 functional, which overestimates the excitations for the individual bases as well as the base pairs. It is therefore crucial to strike a good balance between the amount of local and long-range exact exchange. Thus, this work highlights the difficulties in obtained LC functionals, which provides a good description of both ground- and excited-state properties.

  15. GPU-based finite-size pencil beam algorithm with 3D-density correction for radiotherapy dose calculation

    OpenAIRE

    Gu, Xuejun; Jelen, Urszula; Li, Jinsheng; Jia, Xun; Jiang, Steve B.

    2011-01-01

    Targeting at the development of an accurate and efficient dose calculation engine for online adaptive radiotherapy, we have implemented a finite size pencil beam (FSPB) algorithm with a 3D-density correction method on GPU. This new GPU-based dose engine is built on our previously published ultrafast FSPB computational framework. Dosimetric evaluations against Monte Carlo dose calculations are conducted on 10 IMRT treatment plans (5 head-and-neck cases and 5 lung cases). For all cases, there i...

  16. Optimisation of Simultaneous Tl-201/Tc-99m Dual Isotope Reconstruction with Monte-Carlo-Based Scatter Correction

    Directory of Open Access Journals (Sweden)

    Tuija Kangasmaa

    2012-01-01

    Full Text Available Simultaneous Tl-201/Tc-99m dual isotope myocardial perfusion SPECT is seriously hampered by down-scatter from Tc-99m into the Tl-201 energy window. This paper presents and optimises the ordered-subsets-expectation-maximisation-(OS-EM- based reconstruction algorithm, which corrects the down-scatter using an efficient Monte Carlo (MC simulator. The algorithm starts by first reconstructing the Tc-99m image with attenuation, collimator response, and MC-based scatter correction. The reconstructed Tc-99m image is then used as an input for an efficient MC-based down-scatter simulation of Tc-99m photons into the Tl-201 window. This down-scatter estimate is finally used in the Tl-201 reconstruction to correct the crosstalk between the two isotopes. The mathematical 4D NCAT phantom and physical cardiac phantoms were used to optimise the number of OS-EM iterations where the scatter estimate is updated and the number of MC simulated photons. The results showed that two scatter update iterations and 105 simulated photons are enough for the Tc-99m and Tl-201 reconstructions, whereas 106 simulated photons are needed to generate good quality down-scatter estimates. With these parameters, the entire Tl-201/Tc-99m dual isotope reconstruction can be accomplished in less than 3 minutes.

  17. Optimisation of simultaneous tl-201/tc-99m dual isotope reconstruction with monte-carlo-based scatter correction.

    Science.gov (United States)

    Kangasmaa, Tuija; Kuikka, Jyrki; Sohlberg, Antti

    2012-01-01

    Simultaneous Tl-201/Tc-99m dual isotope myocardial perfusion SPECT is seriously hampered by down-scatter from Tc-99m into the Tl-201 energy window. This paper presents and optimises the ordered-subsets-expectation-maximisation-(OS-EM-) based reconstruction algorithm, which corrects the down-scatter using an efficient Monte Carlo (MC) simulator. The algorithm starts by first reconstructing the Tc-99m image with attenuation, collimator response, and MC-based scatter correction. The reconstructed Tc-99m image is then used as an input for an efficient MC-based down-scatter simulation of Tc-99m photons into the Tl-201 window. This down-scatter estimate is finally used in the Tl-201 reconstruction to correct the crosstalk between the two isotopes. The mathematical 4D NCAT phantom and physical cardiac phantoms were used to optimise the number of OS-EM iterations where the scatter estimate is updated and the number of MC simulated photons. The results showed that two scatter update iterations and 10(5) simulated photons are enough for the Tc-99m and Tl-201 reconstructions, whereas 10(6) simulated photons are needed to generate good quality down-scatter estimates. With these parameters, the entire Tl-201/Tc-99m dual isotope reconstruction can be accomplished in less than 3 minutes.

  18. A GPU-based finite-size pencil beam algorithm with 3D-density correction for radiotherapy dose calculation

    Science.gov (United States)

    Gu, Xuejun; Jelen, Urszula; Li, Jinsheng; Jia, Xun; Jiang, Steve B.

    2011-06-01

    Targeting at the development of an accurate and efficient dose calculation engine for online adaptive radiotherapy, we have implemented a finite-size pencil beam (FSPB) algorithm with a 3D-density correction method on graphics processing unit (GPU). This new GPU-based dose engine is built on our previously published ultrafast FSPB computational framework (Gu et al 2009 Phys. Med. Biol. 54 6287-97). Dosimetric evaluations against Monte Carlo dose calculations are conducted on ten IMRT treatment plans (five head-and-neck cases and five lung cases). For all cases, there is improvement with the 3D-density correction over the conventional FSPB algorithm and for most cases the improvement is significant. Regarding the efficiency, because of the appropriate arrangement of memory access and the usage of GPU intrinsic functions, the dose calculation for an IMRT plan can be accomplished well within 1 s (except for one case) with this new GPU-based FSPB algorithm. Compared to the previous GPU-based FSPB algorithm without 3D-density correction, this new algorithm, though slightly sacrificing the computational efficiency (~5-15% lower), has significantly improved the dose calculation accuracy, making it more suitable for online IMRT replanning.

  19. Reliability of estimating the room volume from a single room impulse response

    NARCIS (Netherlands)

    Kuster, M.

    2008-01-01

    The methods investigated for the room volume estimation are based on geometrical acoustics, eigenmode, and diffuse field models and no data other than the room impulse response are available. The measurements include several receiver positions in a total of 12 rooms of vastly different sizes and aco

  20. Low-cost fabrication of WO3 films using a room temperature and low-vacuum air-spray based deposition system for inorganic electrochromic device applications

    International Nuclear Information System (INIS)

    We report the deposition of tungsten oxide (WO3) thin films on fluorine-doped tin oxide (FTO) and indium-doped tin oxide (ITO) glass substrates by using a room-temperature deposition system based on low-vacuum air-spray for the fabrication of inorganic electrochromic windows. The structure of the WO3 films was characterized using X-ray diffraction, and the surface morphology and film thickness were investigated using scanning electron microscopy and atomic force microscopy. The color of the prepared WO3 films changed from slight yellow to dark blue under applied voltages, demonstrating electrochromism. The WO3 film coated FTO glass exhibited a large electrochromic contrast of up to 50% at a wavelength of 800 nm. The electrochemical properties of the films were examined using cyclic voltammetry and chronocoulometry. - Highlights: • WO3 thin films were fabricated using an air-spray based deposition system at room temperature under low-vacuum conditions. • Dry WO3 particles were directly deposited on FTO and ITO glasses by using a low-cost deposition system. • The FTO glass based WO3 film showed the optical contrast of 50% at a wavelength of 800 nm

  1. Carbon-wire loop based artifact correction outperforms post-processing EEG/fMRI corrections--A validation of a real-time simultaneous EEG/fMRI correction method.

    Science.gov (United States)

    van der Meer, Johan N; Pampel, André; Van Someren, Eus J W; Ramautar, Jennifer R; van der Werf, Ysbrand D; Gomez-Herrero, German; Lepsien, Jöran; Hellrung, Lydia; Hinrichs, Hermann; Möller, Harald E; Walter, Martin

    2016-01-15

    Simultaneous EEG-fMRI combines two powerful neuroimaging techniques, but the EEG signal suffers from severe artifacts in the MRI environment that are difficult to remove. These are the MR scanning artifact and the blood-pulsation artifact--strategies to remove them are a topic of ongoing research. Additionally large, unsystematic artifacts are produced across the full frequency spectrum by the magnet's helium pump (and ventilator) systems which are notoriously hard to remove. As a consequence, experimenters routinely deactivate the helium pump during simultaneous EEG-fMRI acquisitions which potentially risks damaging the MRI system and necessitates more frequent and expensive helium refills. We present a novel correction method addressing both helium pump and ballisto-cardiac (BCG) artifacts, consisting of carbon-wire loops (CWL) as additional sensors to accurately track unpredictable artifacts related to subtle movements in the scanner, and an EEGLAB plugin to perform artifact correction. We compare signal-to-noise metrics of EEG data, corrected with CWL and three conventional correction methods, for helium pump off and on measurements. Because the CWL setup records signals in real-time, it fits requirements of applications where immediate correction is necessary, such as neuro-feedback applications or stimulation time-locked to specific sleep oscillations. The comparison metrics in this paper relate to: (1) the EEG signal itself, (2) the "eyes open vs. eyes closed" effect, and (3) an assessment of how the artifact corrections impacts the ability to perform meaningful correlations between EEG alpha power and the BOLD signal. Results show that the CWL correction corrects for He pump artifact and also produces EEG data more comparable to EEG obtained outside the magnet than conventional post-processing methods.

  2. Ground based measurements on reflectance towards validating atmospheric correction algorithms on IRS-P6 AWiFS data

    Science.gov (United States)

    Rani Sharma, Anu; Kharol, Shailesh Kumar; Kvs, Badarinath; Roy, P. S.

    In Earth observation, the atmosphere has a non-negligible influence on the visible and infrared radiation which is strong enough to modify the reflected electromagnetic signal and at-target reflectance. Scattering of solar irradiance by atmospheric molecules and aerosol generates path radiance, which increases the apparent surface reflectance over dark surfaces while absorption by aerosols and other molecules in the atmosphere causes loss of brightness to the scene, as recorded by the satellite sensor. In order to derive precise surface reflectance from satellite image data, it is indispensable to apply the atmospheric correction which serves to remove the effects of molecular and aerosol scattering. In the present study, we have implemented a fast atmospheric correction algorithm to IRS-P6 AWiFS satellite data which can effectively retrieve surface reflectance under different atmospheric and surface conditions. The algorithm is based on MODIS climatology products and simplified use of Second Simulation of Satellite Signal in Solar Spectrum (6S) radiative transfer code, which is used to generate look-up-tables (LUTs). The algorithm requires information on aerosol optical depth for correcting the satellite dataset. The proposed method is simple and easy to implement for estimating surface reflectance from the at sensor recorded signal, on a per pixel basis. The atmospheric correction algorithm has been tested for different IRS-P6 AWiFS False color composites (FCC) covering the ICRISAT Farm, Patancheru, Hyderabad, India under varying atmospheric conditions. Ground measurements of surface reflectance representing different land use/land cover, i.e., Red soil, Chick Pea crop, Groundnut crop and Pigeon Pea crop were conducted to validate the algorithm and found a very good match between surface reflectance and atmospherically corrected reflectance for all spectral bands. Further, we aggregated all datasets together and compared the retrieved AWiFS reflectance with

  3. Image steganography based on 2k correction and coherent bit length

    Science.gov (United States)

    Sun, Shuliang; Guo, Yongning

    2014-10-01

    In this paper, a novel algorithm is proposed. Firstly, the edge of cover image is detected with Canny operator and secret data is embedded in edge pixels. Sorting method is used to randomize the edge pixels in order to enhance security. Coherent bit length L is determined by relevant edge pixels. Finally, the method of 2k correction is applied to achieve better imperceptibility in stego image. The experiment shows that the proposed method is better than LSB-3 and Jae-Gil Yu's in PSNR and capacity.

  4. The Simulation and Correction to the Brain Deformation Based on the Linear Elastic Model in IGS

    Institute of Scientific and Technical Information of China (English)

    MU Xiao-lan; SONG Zhi-jian

    2004-01-01

    @@ The brain deformation is a vital factor affecting the precision of the IGS and it becomes a hotspot to simulate and correct the brain deformation recently.The research organizations, which firstly resolved the brain deformation with the physical models, have the Image Processing and Analysis department of Yale University, Biomedical Modeling Lab of Vanderbilt University and so on. The former uses the linear elastic model; the latter uses the consolidation model.The linear elastic model only needs to drive the model using the surface displacement of exposed brain cortex,which is more convenient to be measured in the clinic.

  5. Line-ratio based ring artifact correction method using transfer function

    Science.gov (United States)

    Oh, Daejoong; Hwang, Dosik; Kim, Younguk

    2016-03-01

    Computed tomography (CT) has been used for medical purposes. However there are many artifacts at CT images and that makes distorted image. Ring artifact is caused by non-uniform sensitivity of detectors and makes ring shape artifact. Line-ratio method was proposed to solve the problem however there are some problem at specific case. Therefore we propose advanced method to correct ring artifact using transfer function. As a result, ring artifacts can be removed at more global cases. Simulation data shows the proposed method outperforms the conventional line-ratio method.

  6. An All Linear Optical Quantum Memory Based on Quantum Error Correction

    CERN Document Server

    Gingrich, R M; Lee, H; Vatan, F; Dowling, J P; Dowling, Jonathan P.; Gingrich, Robert M.; Kok, Pieter; Lee, Hwang; Vatan, Farrokh

    2003-01-01

    When photons are sent through a fiber as part of a quantum communication protocol, the error that is most difficult to correct is photon loss. Here, we propose and analyze a two-to-four qubit encoding scheme, which can recover the loss of one qubit in the transmission. This device acts as a repeater when it is placed in series to cover a distance larger than the attenuation length of the fiber, and it acts as an optical quantum memory when it is inserted in a fiber loop. We call this dual-purpose device a ``quantum transponder.''

  7. Excess Ni-doping induced enhanced room temperature magneto-functionality in Ni-Mn-Sn based shape memory alloy

    Science.gov (United States)

    Pramanick, S.; Chatterjee, S.; Giri, S.; Majumdar, S.

    2014-09-01

    Present work reports on the observation of large magnetoresistance (˜-30% at 80 kOe) and magnetocaloric effect (˜12 J.kg-1.K-1 for 0-50 kOe) near room temperature (˜290 K) on the Ni-excess ferromagnetic shape memory alloy Ni2.04Mn1.4Sn0.56. The sample can be thought of being derived from the parent Ni2Mn1.4Sn0.6 alloy, where excess Ni was doped at the expense of Sn. Such Ni doping enhances the martensitic transition temperature and for the Ni2.04Mn1.4Sn0.56 it is found to be optimum (288 K). The doped alloy shows enhanced magneto-functional properties as well as reduced saturation magnetization as compared to the undoped counterpart at low temperature. A probable increment of antiferromagnetic correlation between Mn-atoms on Ni substitution can be accounted for the enhanced magneto-functional properties as well as reduction in saturation moment.

  8. Black Phosphorus Based Field Effect Transistors with Simultaneously Achieved Near Ideal Subthreshold Swing and High Hole Mobility at Room Temperature

    Science.gov (United States)

    Liu, Xinke; Ang, Kah-Wee; Yu, Wenjie; He, Jiazhu; Feng, Xuewei; Liu, Qiang; Jiang, He; Dan Tang; Wen, Jiao; Lu, Youming; Liu, Wenjun; Cao, Peijiang; Han, Shun; Wu, Jing; Liu, Wenjun; Wang, Xi; Zhu, Deliang; He, Zhubing

    2016-04-01

    Black phosphorus (BP) has emerged as a promising two-dimensional (2D) material for next generation transistor applications due to its superior carrier transport properties. Among other issues, achieving reduced subthreshold swing and enhanced hole mobility simultaneously remains a challenge which requires careful optimization of the BP/gate oxide interface. Here, we report the realization of high performance BP transistors integrated with HfO2 high-k gate dielectric using a low temperature CMOS process. The fabricated devices were shown to demonstrate a near ideal subthreshold swing (SS) of ~69 mV/dec and a room temperature hole mobility of exceeding >400 cm2/Vs. These figure-of-merits are benchmarked to be the best-of-its-kind, which outperform previously reported BP transistors realized on traditional SiO2 gate dielectric. X-ray photoelectron spectroscopy (XPS) analysis further reveals the evidence of a more chemically stable BP when formed on HfO2 high-k as opposed to SiO2, which gives rise to a better interface quality that accounts for the SS and hole mobility improvement. These results unveil the potential of black phosphorus as an emerging channel material for future nanoelectronic device applications.

  9. Room temperature synthesis of crystalline Sb2S3 for SnO2 photoanode-based solar cell application

    Indian Academy of Sciences (India)

    Anil N Kulkarni; Sandeep A Arote; Habib M Pathan; Rajendra S Patil

    2015-04-01

    The preparation of crystalline antimony sulphide (Sb2S3) by chemical route at room temperature was reported in this paper. The structural, morphological and optical properties of as-synthesized sample were system- atically investigated. X-ray diffraction (XRD) analysis confirms the orthorhombic crystal phase for prepared Sb2S3. Scanning electron microscope (SEM) images show uniform, dense spherical morphology having diameter around 200–220 nm. Energy band gap calculated from optical absorption spectra was observed around 2.17 eV. Contact angle measurement confirms the hydrophilic nature of the deposited film. The photoluminescence analysis shows low green luminescence as well as Stoke's shift for as-prepared Sb2S3. The nanostructured solar cell is fabricated for energy harvesting purpose with Sb2S3-sensitized SnO2 photoanode and polysulphide electrolyte. The solar cell with FTO/SnO2/Sb2S3 photoanode shows OC ∼ 240 mV, sc ∼ 0.640 mA cm−2 and FF ∼ 35%. The working mechanism and energy level diagram of Sb2S3/SnO2 system have been discussed.

  10. Synthesis aspects, structural, spectroscopic, antimicrobial and room temperature ferromagnetism of zinc iodide complex with Schiff based ligand

    Science.gov (United States)

    Shakila, K.; Kalainathan, S.

    2015-01-01

    In this paper, we report the successful growth of complex compound of zinc iodide with thiocarbamide by slow evaporation method. The single crystal XRD study reveals that the crystal belongs to monoclinic system with centrosymmetric space group and powder XRD analysis shows that the perfect crystalline nature of the crystal. The presence of functional group and element were confirmed from FT-IR and EDAX analysis. Optical absorbance of the grown crystal was studied by UV-Vis spectrophotometer. The optical constants were calculated from the optical absorbance data such as refractive index (n), extinction coefficient (K) and reflectance (R). The optical band gap (Eg) of thiocarbamide zinc iodide crystal is 4.22 eV. The magnetic properties of grown crystal have been determined by Vibrating Sample Magnetometry (VSM). Room temperature magnetization revealed a ferromagnetic behaviour for the grown crystal. The antibacterial and antifungal activities of the title compound were performed by well diffusion method and MIC method against the standard bacteria like Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia and against fungus like Aspergillus niger, Rhizopus sps and Penicillium sps. Thermal behaviour of the crystal has been investigated using thermogravimetric analysis (TGA) and differential thermal analysis (DTA).

  11. Excess Ni-doping induced enhanced room temperature magneto-functionality in Ni-Mn-Sn based shape memory alloy

    Energy Technology Data Exchange (ETDEWEB)

    Pramanick, S.; Giri, S.; Majumdar, S., E-mail: sspsm2@iacs.res.in [Department of Solid State Physics, Indian Association for the Cultivation of Science, 2A and B Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032 (India); Chatterjee, S. [UGC-DAE Consortium for Scientific Research, Kolkata Centre, Sector III, LB-8, Salt Lake, Kolkata 700 098 (India)

    2014-09-15

    Present work reports on the observation of large magnetoresistance (∼−30% at 80 kOe) and magnetocaloric effect (∼12 J·kg{sup −1}·K{sup −1} for 0–50 kOe) near room temperature (∼290 K) on the Ni-excess ferromagnetic shape memory alloy Ni{sub 2.04}Mn{sub 1.4}Sn{sub 0.56}. The sample can be thought of being derived from the parent Ni{sub 2}Mn{sub 1.4}Sn{sub 0.6} alloy, where excess Ni was doped at the expense of Sn. Such Ni doping enhances the martensitic transition temperature and for the Ni{sub 2.04}Mn{sub 1.4}Sn{sub 0.56} it is found to be optimum (288 K). The doped alloy shows enhanced magneto-functional properties as well as reduced saturation magnetization as compared to the undoped counterpart at low temperature. A probable increment of antiferromagnetic correlation between Mn-atoms on Ni substitution can be accounted for the enhanced magneto-functional properties as well as reduction in saturation moment.

  12. Black Phosphorus Based Field Effect Transistors with Simultaneously Achieved Near Ideal Subthreshold Swing and High Hole Mobility at Room Temperature.

    Science.gov (United States)

    Liu, Xinke; Ang, Kah-Wee; Yu, Wenjie; He, Jiazhu; Feng, Xuewei; Liu, Qiang; Jiang, He; Dan Tang; Wen, Jiao; Lu, Youming; Liu, Wenjun; Cao, Peijiang; Han, Shun; Wu, Jing; Liu, Wenjun; Wang, Xi; Zhu, Deliang; He, Zhubing

    2016-04-22

    Black phosphorus (BP) has emerged as a promising two-dimensional (2D) material for next generation transistor applications due to its superior carrier transport properties. Among other issues, achieving reduced subthreshold swing and enhanced hole mobility simultaneously remains a challenge which requires careful optimization of the BP/gate oxide interface. Here, we report the realization of high performance BP transistors integrated with HfO2 high-k gate dielectric using a low temperature CMOS process. The fabricated devices were shown to demonstrate a near ideal subthreshold swing (SS) of ~69 mV/dec and a room temperature hole mobility of exceeding >400 cm(2)/Vs. These figure-of-merits are benchmarked to be the best-of-its-kind, which outperform previously reported BP transistors realized on traditional SiO2 gate dielectric. X-ray photoelectron spectroscopy (XPS) analysis further reveals the evidence of a more chemically stable BP when formed on HfO2 high-k as opposed to SiO2, which gives rise to a better interface quality that accounts for the SS and hole mobility improvement. These results unveil the potential of black phosphorus as an emerging channel material for future nanoelectronic device applications.

  13. An irrotation correction on pressure gradient and orthogonal-path integration for PIV-based pressure reconstruction

    Science.gov (United States)

    Wang, Zhongyi; Gao, Qi; Wang, Chengyue; Wei, Runjie; Wang, Jinjun

    2016-06-01

    Particle image velocimetry (PIV)-based pressure reconstruction has become a popular technique in experimental fluid mechanics. Noise or errors in raw velocity field would significantly affect the quality of pressure reconstruction in PIV measurement. To reduce experimental errors in pressure gradient and improve the precision of reconstructed pressure field, a minimal 2-norm criteria-based new technique called irrotation correction (IC) with orthogonal decomposition is developed. The pressure reconstruction is therefore composed of three steps: calculation of pressure gradient from time-resolved velocity fields of PIV, an irrotation correction on the pressure gradient field, and finally a simple orthogonal-path integration (OPI) for pressure. Systematic assessments of IC algorithm are performed on synthetic solid-body rotation flow, direct numerical simulations of a channel flow and an isotropic turbulent flow. The results show that IC is a robust algorithm which can significantly improve the accuracy of pressure reconstruction primarily in the low wave number domain. After irrotation correction, noisy pressure gradient field ideally becomes an irrotational field on which the pressure integration is independent of integrating paths. Therefore, an OPI algorithm is proposed to perform the pressure integration in an efficient way with very few integration paths. This makes the new technique to be a doable method on three-dimensional pressure reconstruction with acceptable computational cost.

  14. Use of mass and toxicity balances in risk-based corrective action decisions at contaminated sites

    International Nuclear Information System (INIS)

    The contaminated groundwater at a sour gas plant facility was studied to identify the chemicals of environmental concern. Simple mass balance principles were used to determine the proportion of organic carbon, organic nitrogen and MicrotoxR toxicity that can be attributed to two process chemicals that have contaminated several sour gas plants in western Canada. The two process chemicals are sulfolane and diisopropanolamine (DIPA). The organic carbon balance was calculated by determining the molar contribution of sulfolane and DIPA relative to the mass of carboxylic acid-corrected dissolved organic carbon. Organic carbon balances ranged from 44 to 96 per cent. The organic nitrogen balance was calculated by determining the molar contribution of DIPA relative to the mass of ammonium ion-corrected dissolved Kjeldahl nitrogen. The nitrogen balances were highly variable between 8 to 48 per cent for samples with organic nitrogen concentrations between 10 and 32 mg/L. The MicrotoxR toxicity balance was calculated by determining the proportions of toxicity that could be accounted for by pure phase sulfolane and DIPA. The MicrotoxR toxicity balance for samples that showed significant toxicity ranged from 71 to 122 per cent

  15. Single-image-based solution for optics temperature-dependent nonuniformity correction in an uncooled long-wave infrared camera.

    Science.gov (United States)

    Cao, Yanpeng; Tisse, Christel-Loic

    2014-02-01

    In this Letter, we propose an efficient and accurate solution to remove temperature-dependent nonuniformity effects introduced by the imaging optics. This single-image-based approach computes optics-related fixed pattern noise (FPN) by fitting the derivatives of correction model to the gradient components, locally computed on an infrared image. A modified bilateral filtering algorithm is applied to local pixel output variations, so that the refined gradients are most likely caused by the nonuniformity associated with optics. The estimated bias field is subtracted from the raw infrared imagery to compensate the intensity variations caused by optics. The proposed method is fundamentally different from the existing nonuniformity correction (NUC) techniques developed for focal plane arrays (FPAs) and provides an essential image processing functionality to achieve completely shutterless NUC for uncooled long-wave infrared (LWIR) imaging systems.

  16. CEBAF Control Room Renovation

    CERN Document Server

    Spata, Michael; Fanning, Harry; Oren, Tom C

    2005-01-01

    The Machine Control Center at Jefferson Lab's Continuous Electron Beam Accelerator Facility was initially constructed in the early 1990s and based on proven technology of that era. Through our experience over the last 15 years and in our planning for the facilities 12 GeV upgrade we reevaluated the control room environment to capitalize on emerging visualization and display technologies and improve on workflow processes and ergonomic attributes. This effort also sets the foundation for the redevelopment of the accelerator's control system to deliver high reliability performance with improvements in beam specifications management and information flow. The complete renovation was performed over a three-week period with no interruption to beam operations. We present the results of this effort.

  17. Highly efficient organic solar Cells based on a robust room-temperature solution-processed copper iodide hole transporter

    KAUST Repository

    Zhao, Kui

    2015-07-30

    Achieving high performance and reliable organic solar cells hinges on the development of stable and energetically suitable hole transporting buffer layers in tune with the electrode and photoactive materials of the solar cell stack. Here we have identified solution-processed copper(I) iodide (CuI) thin films with low-temperature processing conditions as an effective hole–transporting layer (HTL) for a wide range of polymer:fullerene bulk heterojunction (BHJ) systems. The solar cells using CuI HTL show higher power conversion efficiency (PCE) in standard device structure for polymer blends, up to PCE of 8.8%, as compared with poly(3,4-ethylenedioxy-thiophene):poly(styrenesulfonate) (PEDOT:PSS) HTL, for a broad range of polymer:fullerene systems. The CuI layer properties and solar cell device behavior are shown to be remarkably robust and insensitive to a wide range of processing conditions of the HTL, including processing solvent, annealing temperature (room temperature up to 200 °C), and film thickness. CuI is also shown to improve the overall lifetime of solar cells in the standard architecture as compared to PEDOT:PSS. We further demonstrate promising solar cell performance when using CuI as top HTL in an inverted device architecture. The observation of uncommon properties, such as photoconductivity of CuI and templating effects on the BHJ layer formation, are also discussed. This study points to CuI as being a good candidate to replace PEDOT:PSS in solution-processed solar cells thanks to the facile implementation and demonstrated robustness of CuI thin films.

  18. Error Correction in Classroom

    Institute of Scientific and Technical Information of China (English)

    Dr. Grace Zhang

    2000-01-01

    Error correction is an important issue in foreign language acquisition. This paper investigates how students feel about the way in which error correction should take place in a Chinese-as-a foreign-language classroom, based on empirical data of a large scale. The study shows that there is a general consensus that error correction is necessary. In terms of correction strategy, the students preferred a combination of direct and indirect corrections, or a direct only correction. The former choice indicates that students would be happy to take either so long as the correction gets done.Most students didn't mind peer correcting provided it is conducted in a constructive way. More than halfofthe students would feel uncomfortable ifthe same error they make in class is corrected consecutively more than three times. Taking these findings into consideration, we may want to cncourage peer correcting, use a combination of correction strategies (direct only if suitable) and do it in a non-threatening and sensitive way. It is hoped that this study would contribute to the effectiveness of error correction in a Chinese language classroom and it may also have a wider implication on other languages.

  19. Microcontroller–Based Modified SEPIC Converter for Driving Lamp with Power Factor Correction

    Directory of Open Access Journals (Sweden)

    S.Yamuna

    2014-07-01

    Full Text Available A methodological study of electronic ballast for electrode less lamps including design and development issues is presented in this paper. The ballast is intended to feed a 300 W ultra violet lamp at 100 kHz with dimming feature. The proposed topology is composed of a Single-Ended Primary Inductance Converter (SEPIC, used as power factor correction (PFC stage, integrated with a resonant half-bridge inverter, used as lamp power control (PC stage. The integration of both stages is proposed in this paper, in order to reduce the number of active switches, as well as to simplify the required driving and control circuitry for this application. The implemented topology attained very high power factor (0.9982, and low line current total harmonic distortion (THD (1.86%, without using electromagnetic interference (EMI filter, while the measured efficiency was 90% at nominal lamp power.

  20. Corrected knife-edge-based reconstruction of tightly focused higher order beams

    CERN Document Server

    Orlov, S; Marchenko, P; Banzer, P; Leuchs, G

    2016-01-01

    The knife-edge method is an established technique for profiling of even tightly focused light beams. However the straightforward implementation of this method fails if the materials and geometry of the knife-edges are not chosen carefully or in particular if knife-edges are used that are made of pure materials. In these cases artifacts are introduced in the shape and position of the reconstructed beam profile due to the interaction of the light beam under study with the knife. Hence, corrections to the standard knife-edge evaluation method are required. Here we investigate the knife-edge method for highly focused radially and azimuthally polarized beams and their linearly polarized constituents. We introduce relative shifts for those constituents and report on the consistency with the case of a linearly polarized Gaussian beam. An adapted knife-edge reconstruction technique is presented and proof-of-concept tests demonstrating the reconstruction of beam profiles are shown.

  1. Improving operating room safety

    OpenAIRE

    Garrett Jill; Hurlbert Scott N

    2009-01-01

    Abstract Despite the introduction of the Universal Protocol, patient safety in surgery remains a daily challenge in the operating room. This present study describes one community health system's efforts to improve operating room safety through human factors training and ultimately the development of a surgical checklist. Using a combination of formal training, local studies documenting operating room safety issues and peer to peer mentoring we were able to substantially change the culture of ...

  2. Brown carbon and thermal-optical analysis: A correction based on optical multi-wavelength apportionment of atmospheric aerosols

    Science.gov (United States)

    Massabò, D.; Caponi, L.; Bove, M. C.; Prati, P.

    2016-01-01

    Thermo-optical analysis is widely adopted for the quantitative determination of total, TC, organic, OC and elemental, EC, Carbon in aerosol samples collected on quartz fibre filters. Nevertheless, the methodology presents several issues in particular about the artefacts related to the formation of pyrolytic carbon. It is usually neglected the uncertainty due to the possible presence of brown carbon (BrC) in the sample under analysis, i.e. the optically active fraction of OC produced by biomass burning and with characteristics intermediate between OC and EC. We introduce here a novel correction to the standard thermo-optical protocol based on the determination of the fraction of the sample absorbance due to the (possible) presence of BrC. This is achievable thanks to the coupled use of the Multi Wavelength Absorbance Analyser (MWAA) of the University of Genoa and a standard Sunset Inc. EC/OC analyser. Our correction provides a firmer OC/EC separation as well as an operative quantification of the BrC mass. The methodology has been validated against independent determination of the levoglucosan content in the same filters sent to the Sunset analysis. Corrections up to 23% in the OC and EC values, determined via the standard and new thermo-optical analysis, have been found in a set of PM10 (i.e. Particulate Matter with aerodynamic diameter less than 10 μm) samples collected wintertime at a mountain site in Northern Italy.

  3. 27-day variation of the GCR intensity based on corrected and uncorrected for geomagnetic disturbances data of neutron monitors

    CERN Document Server

    Alania, M V; Wawrzynczak, A; Sdobnov, V E; Kravtsova, M V

    2015-01-01

    We study 27-day variations of the galactic cosmic ray (GCR) intensity for 2005- 2008 period of the solar cycle #23. We use neutron monitors (NMs) data corrected and uncorrected for geomagnetic disturbances. Besides the limited time intervals when the 27-day variations are clearly established, always exist some feeble 27-day variations in the GCR 5 intensity related to the constantly present weak heliolongitudinal asymmetry in the heliosphere. We calculate the amplitudes of the 27-day variation of the GCR intensity based on the NMs data corrected and uncorrected for geomagnetic disturbances. We show that these amplitudes do not differ for NMs with cut-off rigidities smaller than 4-5 GV comparing with NMs of higher cut-off rigidities. Rigidity spectrum of the 27-day variation of the GCR intensity found in the uncorrected data is soft while it is hard in the case of the corrected data. For both cases exists definite tendency of softening the temporal changes of the 27-day variation's rigidity spectrum in period ...

  4. Cathode design investigation based on iterative correction of predicted profile errors in electrochemical machining of compressor blades

    Institute of Scientific and Technical Information of China (English)

    Zhu Dong; Liu Cheng; Xu Zhengyang; Liu Jia

    2016-01-01

    Electrochemical machining (ECM) is an effective and economical manufacturing method for machining hard-to-cut metal materials that are often used in the aerospace field. Cathode design is very complicated in ECM and is a core problem influencing machining accuracy, especially for complex profiles such as compressor blades in aero engines. A new cathode design method based on iterative correction of predicted profile errors in blade ECM is proposed in this paper. A math-ematical model is first built according to the ECM shaping law, and a simulation is then carried out using ANSYS software. A dynamic forming process is obtained and machining gap distributions at different stages are analyzed. Additionally, the simulation deviation between the prediction profile and model is improved by the new method through correcting the initial cathode profile. Further-more, validation experiments are conducted using cathodes designed before and after the simulation correction. Machining accuracy for the optimal cathode is improved markedly compared with that for the initial cathode. The experimental results illustrate the suitability of the new method and that it can also be applied to other complex engine components such as diffusers.

  5. Local strain redistribution corrections for a simplified inelastic analysis procedure based on an elastic finite-element analysis

    Science.gov (United States)

    Kaufman, A.; Hwang, S. Y.

    1985-01-01

    Strain redistribution corrections were developed for a simplified inelastic analysis procedure to economically calculate material cyclic response at the critical location of a structure for life prediction proposes. The method was based on the assumption that the plastic region in the structure is local and the total strain history required for input can be defined from elastic finite-element analyses. Cyclic stress-strain behavior was represented by a bilinear kinematic hardening model. The simplified procedure predicts stress-strain response with reasonable accuracy for thermally cycled problems but needs improvement for mechanically load-cycled problems. Neuber-type corrections were derived and incorporated in the simplified procedure to account for local total strain redistribution under cyclic mechanical loading. The corrected simplified method was used on a mechanically load-cycled benchmark notched-plate problem. The predicted material response agrees well with the nonlinear finite-element solutions for the problem. The simplified analysis computer program was 0.3% of the central processor unit time required for a nonlinear finite-element analysis.

  6. Cathode design investigation based on iterative correction of predicted profile errors in electrochemical machining of compressor blades

    Directory of Open Access Journals (Sweden)

    Zhu Dong

    2016-08-01

    Full Text Available Electrochemical machining (ECM is an effective and economical manufacturing method for machining hard-to-cut metal materials that are often used in the aerospace field. Cathode design is very complicated in ECM and is a core problem influencing machining accuracy, especially for complex profiles such as compressor blades in aero engines. A new cathode design method based on iterative correction of predicted profile errors in blade ECM is proposed in this paper. A mathematical model is first built according to the ECM shaping law, and a simulation is then carried out using ANSYS software. A dynamic forming process is obtained and machining gap distributions at different stages are analyzed. Additionally, the simulation deviation between the prediction profile and model is improved by the new method through correcting the initial cathode profile. Furthermore, validation experiments are conducted using cathodes designed before and after the simulation correction. Machining accuracy for the optimal cathode is improved markedly compared with that for the initial cathode. The experimental results illustrate the suitability of the new method and that it can also be applied to other complex engine components such as diffusers.

  7. Corneal storage at room temperature.

    Science.gov (United States)

    Sachs, U; Goldman, K; Valenti, J; Kaufman, H E

    1978-06-01

    Short-term eye banking is based mainly on moist chamber and McCarey-Kaufman medium (M-K medium) preservation. Both involve a controlled 4 C temperature for storage. Warming the cornea to room temperature, however, drastically affects the endothelial viability. On enzymatic staining and histological study, the M-K medium-stored rabbit corneas had more normal endothelium than did "moist chamber" eyes when storage was prolonged for seven days at room temperature. In human corneas that were kept at 4 C for 24 hours and then exposed to a temperature of 25 C, destruction of organelles had occurred by six hours and was increased by 12 hours. Corneas that were kept in M-K medium had relatively intact endothelium after four days, but cell disruption and vacuolation was present by the seventh day. The M-K medium, therefore, affords protection to tissue warmed to room temperature, where metabolic activity is resumed. PMID:350203

  8. Production of CNT-taxol-embedded PCL microspheres using an ammonium-based room temperature ionic liquid: as a sustained drug delivery system.

    Science.gov (United States)

    Kim, Seong Yeol; Hwang, Ji-Young; Seo, Jae-Won; Shin, Ueon Sang

    2015-03-15

    We describe a one-pot method for the mass production of polymeric microspheres containing water-soluble carbon-nanotube (w-CNT)-taxol complexes using an ammonium-based room temperature ionic liquid. Polycaprolactone (PCL), trioctylmethylammonium chloride (TOMAC; liquid state from -20 to 240°C), and taxol were used, respectively, as a model polymer, room temperature ionic liquid, and drug. Large quantities of white colored PCL powder without w-CNT-taxol complexes and gray colored PCL powders containing w-CNT-taxol (1:1 or 1:2 wt/wt) complexes were produced by phase separation between the hydrophilic TOMAC and the hydrophobic PCL. Both microsphere types had a uniform, spherical structure of average diameter 3-5μm. The amount of taxol embedded in PCL microspheres was determined by HPLC and (1)H NMR to be 8-12μg per 1.0mg of PCL (loading capacity (LC): 0.8-1.2%; entrapment efficiency (EE): 16-24%). An in vitro HPLC release assay showed sustain release of taxol without an initial burst over 60days at an average rate of 0.003-0.0073mg per day. The viability patterns of human breast cancer cells (MCF-7) for PCTx-1 and -2 showed dose-dependent inhibitory effects. In the presence of PCTx-1 and -2, the MCF-7 cells showed high viability in the concentration level of, respectably, <70 and <5μg/mL.

  9. Determination of Glucose by Affinity Adsorption Solid Substrate-room Temperature Phosphorimetry Based on Triticum Vulgare Lectin Labeled with Silicon Dioxide Nanoparticle Containing Fiuorescein Isothiocyanate

    Institute of Scientific and Technical Information of China (English)

    LIU Jia-Ming; LIU Zhen-Bo; LI Zhi-Ming; HE Hang-Xia; LIN Wei-Nü; HUANG Ya-Hong; WANG Fang-Mei

    2008-01-01

    In the presence of heavy atom perturber Pb2+,silicon dioxide nanoparticle containing fluorescein isothiocyanate (FITC-SiO2) could emit a strong and stable room temperature phosphorescence (RTP) signal on the surface of acetyl cellulose membrane (ACM).It was found in the research that a quantitative specific affinity adsorption (AA) reaction between triticum vulgare lectin (WGA) labeled with luminescent nanoparticle and glucose (g)could be carried on the surface of ACM.The product (WGA-G-WGA-FITC-SiO2) of the reaction could emit a stronger RTP signal,and the △Ip had linear correlation to the content of G.According to the facts above,a new method to determine G by affinity adsorption solid substrate room temperature phosphorimetry (AA-SS-RTP) was established,based on WGA labeled with FITC-SiO2.The detection limit (LD) of this method calculated by 3Sb/k was 0.47 pg·spot-1 (corresponding to a concentration value 1.2 × 10-9 g·mL-1,namely 5.3 × 10-9 mol·L-1),the sensitivity was high.Meanwhile,the mechanism for the determination of G by AA-SS-RTP was discussed.

  10. A Physically Based Algorithm for Non-Blackbody Correction of Cloud-Top Temperature and Application to Convection Study

    Science.gov (United States)

    Wang, Chunpeng; Lou, Zhengzhao Johnny; Chen, Xiuhong; Zeng, Xiping; Tao, Wei-Kuo; Huang, Xianglei

    2014-01-01

    Cloud-top temperature (CTT) is an important parameter for convective clouds and is usually different from the 11-micrometers brightness temperature due to non-blackbody effects. This paper presents an algorithm for estimating convective CTT by using simultaneous passive [Moderate Resolution Imaging Spectroradiometer (MODIS)] and active [CloudSat 1 Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO)] measurements of clouds to correct for the non-blackbody effect. To do this, a weighting function of the MODIS 11-micrometers band is explicitly calculated by feeding cloud hydrometer profiles from CloudSat and CALIPSO retrievals and temperature and humidity profiles based on ECMWF analyses into a radiation transfer model.Among 16 837 tropical deep convective clouds observed by CloudSat in 2008, the averaged effective emission level (EEL) of the 11-mm channel is located at optical depth; approximately 0.72, with a standard deviation of 0.3. The distance between the EEL and cloud-top height determined by CloudSat is shown to be related to a parameter called cloud-top fuzziness (CTF), defined as the vertical separation between 230 and 10 dBZ of CloudSat radar reflectivity. On the basis of these findings a relationship is then developed between the CTF and the difference between MODIS 11-micrometers brightness temperature and physical CTT, the latter being the non-blackbody correction of CTT. Correction of the non-blackbody effect of CTT is applied to analyze convective cloud-top buoyancy. With this correction, about 70% of the convective cores observed by CloudSat in the height range of 6-10 km have positive buoyancy near cloud top, meaning clouds are still growing vertically, although their final fate cannot be determined by snapshot observations.

  11. Dixon imaging-based partial volume correction improves quantification of choline detected by breast 3D-MRSI

    Energy Technology Data Exchange (ETDEWEB)

    Minarikova, Lenka; Gruber, Stephan; Bogner, Wolfgang; Trattnig, Siegfried; Chmelik, Marek [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, MR Center of Excellence, Vienna (Austria); Pinker-Domenig, Katja; Baltzer, Pascal A.T.; Helbich, Thomas H. [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Vienna (Austria)

    2014-09-14

    Our aim was to develop a partial volume (PV) correction method of choline (Cho) signals detected by breast 3D-magnetic resonance spectroscopic imaging (3D-MRSI), using information from water/fat-Dixon MRI. Following institutional review board approval, five breast cancer patients were measured at 3 T. 3D-MRSI (1 cm{sup 3} resolution, duration ∝11 min) and Dixon MRI (1 mm{sup 3}, ∝2 min) were measured in vivo and in phantoms. Glandular/lesion tissue was segmented from water/fat-Dixon MRI and transformed to match the resolution of 3D-MRSI. The resulting PV values were used to correct Cho signals. Our method was validated on a two-compartment phantom (choline/water and oil). PV values were correlated with the spectroscopic water signal. Cho signal variability, caused by partial-water/fat content, was tested in 3D-MRSI voxels located in/near malignant lesions. Phantom measurements showed good correlation (r = 0.99) with quantified 3D-MRSI water signals, and better homogeneity after correction. The dependence of the quantified Cho signal on the water/fat voxel composition was significantly (p < 0.05) reduced using Dixon MRI-based PV correction, compared to the original uncorrected data (1.60-fold to 3.12-fold) in patients. The proposed method allows quantification of the Cho signal in glandular/lesion tissue independent of water/fat composition in breast 3D-MRSI. This can improve the reproducibility of breast 3D-MRSI, particularly important for therapy monitoring. (orig.)

  12. GTE: a new FFT based software to compute terrain correction on airborne gravity surveys in spherical approximation.

    Science.gov (United States)

    Capponi, Martina; Sampietro, Daniele; Sansò, Fernando

    2016-04-01

    The computation of the vertical attraction due to the topographic masses (Terrain Correction) is still a matter of study both in geodetic as well as in geophysical applications. In fact it is required in high precision geoid estimation by the remove-restore technique and it is used to isolate the gravitational effect of anomalous masses in geophysical exploration. This topographical effect can be evaluated from the knowledge of a Digital Terrain Model in different ways: e.g. by means of numerical integration, by prisms, tesseroids, polyedra or Fast Fourier Transform (FFT) techniques. The increasing resolution of recently developed digital terrain models, the increasing number of observation points due to extensive use of airborne gravimetry and the increasing accuracy of gravity data represents nowadays major issues for the terrain correction computation. Classical methods such as prism or point masses approximations are indeed too slow while Fourier based techniques are usually too approximate for the required accuracy. In this work a new software, called Gravity Terrain Effects (GTE), developed in order to guarantee high accuracy and fast computation of terrain corrections is presented. GTE has been thought expressly for geophysical applications allowing the computation not only of the effect of topographic and bathymetric masses but also those due to sedimentary layers or to the Earth crust-mantle discontinuity (the so called Moho). In the present contribution we summarize the basic theory of the software and its practical implementation. Basically the GTE software is based on a new algorithm which, by exploiting the properties of the Fast Fourier Transform, allows to quickly compute the terrain correction, in spherical approximation, at ground or airborne level. Some tests to prove its performances are also described showing GTE capability to compute high accurate terrain corrections in a very short time. Results obtained for a real airborne survey with GTE

  13. TH-A-18C-04: Ultrafast Cone-Beam CT Scatter Correction with GPU-Based Monte Carlo Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y [UT Southwestern Medical Center, Dallas, TX (United States); Southern Medical University, Guangzhou (China); Bai, T [UT Southwestern Medical Center, Dallas, TX (United States); Xi' an Jiaotong University, Xi' an (China); Yan, H; Ouyang, L; Wang, J; Pompos, A; Jiang, S; Jia, X [UT Southwestern Medical Center, Dallas, TX (United States); Zhou, L [Southern Medical University, Guangzhou (China)

    2014-06-15

    Purpose: Scatter artifacts severely degrade image quality of cone-beam CT (CBCT). We present an ultrafast scatter correction framework by using GPU-based Monte Carlo (MC) simulation and prior patient CT image, aiming at automatically finish the whole process including both scatter correction and reconstructions within 30 seconds. Methods: The method consists of six steps: 1) FDK reconstruction using raw projection data; 2) Rigid Registration of planning CT to the FDK results; 3) MC scatter calculation at sparse view angles using the planning CT; 4) Interpolation of the calculated scatter signals to other angles; 5) Removal of scatter from the raw projections; 6) FDK reconstruction using the scatter-corrected projections. In addition to using GPU to accelerate MC photon simulations, we also use a small number of photons and a down-sampled CT image in simulation to further reduce computation time. A novel denoising algorithm is used to eliminate MC scatter noise caused by low photon numbers. The method is validated on head-and-neck cases with simulated and clinical data. Results: We have studied impacts of photo histories, volume down sampling factors on the accuracy of scatter estimation. The Fourier analysis was conducted to show that scatter images calculated at 31 angles are sufficient to restore those at all angles with <0.1% error. For the simulated case with a resolution of 512×512×100, we simulated 10M photons per angle. The total computation time is 23.77 seconds on a Nvidia GTX Titan GPU. The scatter-induced shading/cupping artifacts are substantially reduced, and the average HU error of a region-of-interest is reduced from 75.9 to 19.0 HU. Similar results were found for a real patient case. Conclusion: A practical ultrafast MC-based CBCT scatter correction scheme is developed. The whole process of scatter correction and reconstruction is accomplished within 30 seconds. This study is supported in part by NIH (1R01CA154747-01), The Core Technology Research

  14. Wavelet based error correction and predictive uncertainty of a hydrological forecasting system

    Science.gov (United States)

    Bogner, Konrad; Pappenberger, Florian; Thielen, Jutta; de Roo, Ad

    2010-05-01

    River discharge predictions most often show errors with scaling properties of unknown source and statistical structure that degrade the quality of forecasts. This is especially true for lead-time ranges greater then a few days. Since the European Flood Alert System (EFAS) provides discharge forecasts up to ten days ahead, it is necessary to take these scaling properties into consideration. For example the range of scales for the error that occurs at the spring time will be caused by long lasting snowmelt processes, and is by far larger then the error, that appears during the summer period and is caused by convective rain fields of short duration. The wavelet decomposition is an excellent way to provide the detailed model error at different levels in order to estimate the (unobserved) state variables more precisely. A Vector-AutoRegressive model with eXogenous input (VARX) is fitted for the different levels of wavelet decomposition simultaneously and after predicting the next time steps ahead for each scale, a reconstruction formula is applied to transform the predictions in the wavelet domain back to the original time domain. The Bayesian Uncertainty Processor (BUP) developed by Krzysztofowicz is an efficient method to estimate the full predictive uncertainty, which is derived by integrating the hydrological model uncertainty and the meteorological input uncertainty. A hydrological uncertainty processor has been applied to the error corrected discharge series at first in order to derive the predictive conditional distribution under the hypothesis that there is no input uncertainty. The uncertainty of the forecasted meteorological input forcing the hydrological model is derived from the combination of deterministic weather forecasts and ensemble predictions systems (EPS) and the Input Processor maps this input uncertainty into the output uncertainty under the hypothesis that there is no hydrological uncertainty. The main objective of this Bayesian forecasting system

  15. A GPU-based finite-size pencil beam algorithm with 3D-density correction for radiotherapy dose calculation

    OpenAIRE

    Gu, Xuejun; Jelen, Urszula; Li, Jinsheng; Jia, Xun; Jiang, Steve B.

    2011-01-01

    Targeting at the development of an accurate and efficient dose calculation engine for online adaptive radiotherapy, we have implemented a finite size pencil beam (FSPB) algorithm with a 3D-density correction method on GPU. This new GPU-based dose engine is built on our previously published ultrafast FSPB computational framework [Gu et al. Phys. Med. Biol. 54 6287-97, 2009]. Dosimetric evaluations against Monte Carlo dose calculations are conducted on 10 IMRT treatment plans (5 head-and-neck c...

  16. Geo-correction Algorithm Based on Equivalent RD Model for ScanSAR of HJ-1-C Satellite

    OpenAIRE

    Liu Jia-yin; Wen Shuang-yan; Zhang Hong-yi; Hong Wen

    2014-01-01

    HJ-1-C satellite is the first Synthetic Aperture Radar (SAR) satellite for civilian use in China, and it has a strip and scan mode. According to the characteristics of the ScanSAR of the HJ-1-C satellite, a geo-correction algorithm based on an equivalent RD model has been outlined in this paper on the basis of an ECS image processing algorithm and a traditional Range-Doppler location method. An azimuth mosaic was presented by a time series relationship, then the different burst was stitched b...

  17. Assessing the optimal location for alcohol-based hand rub dispensers in a patient room in an intensive care unit

    NARCIS (Netherlands)

    Boog, M.C.; Erasmus, V.; De Graaf, J.M.; Van Beeck, E.H.E.; Melles, M.; Van Beeck, E.F.

    2013-01-01

    Background The introduction of alcohol-based hand rub dispensers has had a positive influence on compliance of healthcare workers with the recommended guidelines for hand hygiene. However, establishing the best location for alcohol-based hand rub dispensers remains a problem, and no method is curren

  18. Study of CT-based positron range correction in high resolution 3D PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Cal-Gonzalez, J., E-mail: jacobo@nuclear.fis.ucm.es [Grupo de Fisica Nuclear, Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Herraiz, J.L. [Grupo de Fisica Nuclear, Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Espana, S. [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Vicente, E. [Grupo de Fisica Nuclear, Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Cientificas (CSIC), Madrid (Spain); Herranz, E. [Grupo de Fisica Nuclear, Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Desco, M. [Unidad de Medicina y Cirugia Experimental, Hospital General Universitario Gregorio Maranon, Madrid (Spain); Vaquero, J.J. [Dpto. de Bioingenieria e Ingenieria Espacial, Universidad Carlos III, Madrid (Spain); Udias, J.M. [Grupo de Fisica Nuclear, Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain)

    2011-08-21

    Positron range limits the spatial resolution of PET images and has a different effect for different isotopes and positron propagation materials. Therefore it is important to consider it during image reconstruction, in order to obtain optimal image quality. Positron range distributions for most common isotopes used in PET in different materials were computed using the Monte Carlo simulations with PeneloPET. The range profiles were introduced into the 3D OSEM image reconstruction software FIRST and employed to blur the image either in the forward projection or in the forward and backward projection. The blurring introduced takes into account the different materials in which the positron propagates. Information on these materials may be obtained, for instance, from a segmentation of a CT image. The results of introducing positron blurring in both forward and backward projection operations was compared to using it only during forward projection. Further, the effect of different shapes of positron range profile in the quality of the reconstructed images with positron range correction was studied. For high positron energy isotopes, the reconstructed images show significant improvement in spatial resolution when positron range is taken into account during reconstruction, compared to reconstructions without positron range modeling.

  19. Biomechanical Implications of Corrective Surgery for FAI: An Evidence-based Review.

    Science.gov (United States)

    Sampson, Joshua D; Safran, Marc R

    2015-12-01

    Femoroacetabular impingement (FAI) has been identified as a potential cause of hip osteoarthritis. The goal of FAI surgery is to relieve pain, and hopefully delay or prevent osteoarthritis of the hip. Several studies have now demonstrated favorable clinical outcomes after arthroscopic and open surgical correction of symptomatic FAI. The concept is restoration of normal hip anatomy may result in improved biomechanical function and kinematics of the hip, which may prevent or delay the progression of osteoarthritis. Although many clinical studies demonstrate restoration of "normal" anatomy, there are few studies evaluating improvement of biomechanics and function. To date, only 5 studies have been published in the English literature that study biomechanics and/or kinematics of the hip both preoperatively and postoperatively. At this point in the understanding of FAI, critical analysis of the literature suggests that FAI surgery can improve several parameters of biomechanical hip function. However, the impact of these improved biomechanics on the natural history and progression of degenerative changes in patients that are treated for symptomatic FAI has not been demonstrated.

  20. Ionospheric Correction Based on Ingestion of Global Ionospheric Maps into the NeQuick 2 Model

    Directory of Open Access Journals (Sweden)

    Xiao Yu

    2015-01-01

    Full Text Available The global ionospheric maps (GIMs, generated by Jet Propulsion Laboratory (JPL and Center for Orbit Determination in Europe (CODE during a period over 13 years, have been adopted as the primary source of data to provide global ionospheric correction for possible single frequency positioning applications. The investigation aims to assess the performance of new NeQuick model, NeQuick 2, in predicting global total electron content (TEC through ingesting the GIMs data from the previous day(s. The results show good performance of the GIMs-driven-NeQuick model with average 86% of vertical TEC error less than 10 TECU, when the global daily effective ionization indices (Az versus modified dip latitude (MODIP are constructed as a second order polynomial. The performance of GIMs-driven-NeQuick model presents variability with solar activity and behaves better during low solar activity years. The accuracy of TEC prediction can be improved further through performing a four-coefficient function expression of Az versus MODIP. As more measurements from earlier days are involved in the Az optimization procedure, the accuracy may decrease. The results also reveal that more efforts are needed to improve the NeQuick 2 model capabilities to represent the ionosphere in the equatorial and high-latitude regions.

  1. Performance evaluation of DWT based image watermarking using error correcting codes.

    Directory of Open Access Journals (Sweden)

    Shaikh Rakhshan Anjum, Priyanka Verma

    2012-12-01

    Full Text Available Due to excessive proliferation of digital multimedia, the need of protecting the ownership of digital media becomes a major issue. For content protection digital image watermarking plays an important role in Multimedia security fields. Methods developed under this are used to protect Intellectual property rights of digital data such as video, image, audio, etc. without affecting the fidelity of the original data. In this paper we show that if the logo is coded using error correcting codes before being embedded into the watermarked image the robustness of the watermark is increased. Different codes that are taken into consideration in this paper are Hamming and cyclic codes. Here the encoded and embedded watermarked image is considered to be encountering an AWG noise while transmission. We observe that the SNR and PSNR of the watermarked image even in AWGN channel are better when logo is coded before embedding. Also we observe that Hamming codes SNR and PSNR are much more superior to cyclic codes.

  2. Performance evaluation of DWT based image watermarking using error correcting codes

    Directory of Open Access Journals (Sweden)

    Shaikh Rakhshan Anjum

    2012-12-01

    Full Text Available Due to excessive proliferation of digital multimedia, the need of protecting the ownership of digital media becomes a major issue. For content protection digital image watermarking plays an important role in Multimedia security fields. Methods developed under this are used to protect Intellectual property rights of digital data such as video, image, audio, etc. without affecting the fidelity of the original data. In this paper we show that if the logo is coded using error correcting codes before being embedded into the watermarked image the robustness of the watermark is increased. Different codes that are taken into consideration in this paper are Hamming and cyclic codes. Here the encoded and embedded watermarked image is considered to be encountering an AWG noise while transmission. We observe that the SNR and PSNR of the watermarked image even in AWGN channel are better when logo is coded before embedding. Also we observe that Hamming codes SNR and PSNR are much more superior to cyclic codes.

  3. Biomechanical Implications of Corrective Surgery for FAI: An Evidence-based Review.

    Science.gov (United States)

    Sampson, Joshua D; Safran, Marc R

    2015-12-01

    Femoroacetabular impingement (FAI) has been identified as a potential cause of hip osteoarthritis. The goal of FAI surgery is to relieve pain, and hopefully delay or prevent osteoarthritis of the hip. Several studies have now demonstrated favorable clinical outcomes after arthroscopic and open surgical correction of symptomatic FAI. The concept is restoration of normal hip anatomy may result in improved biomechanical function and kinematics of the hip, which may prevent or delay the progression of osteoarthritis. Although many clinical studies demonstrate restoration of "normal" anatomy, there are few studies evaluating improvement of biomechanics and function. To date, only 5 studies have been published in the English literature that study biomechanics and/or kinematics of the hip both preoperatively and postoperatively. At this point in the understanding of FAI, critical analysis of the literature suggests that FAI surgery can improve several parameters of biomechanical hip function. However, the impact of these improved biomechanics on the natural history and progression of degenerative changes in patients that are treated for symptomatic FAI has not been demonstrated. PMID:26524550

  4. Air Temperature Error Correction Based on Solar Radiation in an Economical Meteorological Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Xingming Sun

    2015-07-01

    Full Text Available Air temperature (AT is an extremely vital factor in meteorology, agriculture, military, etc., being used for the prediction of weather disasters, such as drought, flood, frost, etc. Many efforts have been made to monitor the temperature of the atmosphere, like automatic weather stations (AWS. Nevertheless, due to the high cost of specialized AT sensors, they cannot be deployed within a large spatial density. A novel method named the meteorology wireless sensor network relying on a sensing node has been proposed for the purpose of reducing the cost of AT monitoring. However, the temperature sensor on the sensing node can be easily influenced by environmental factors. Previous research has confirmed that there is a close relation between AT and solar radiation (SR. Therefore, this paper presents a method to decrease the error of sensed AT, taking SR into consideration. In this work, we analyzed all of the collected data of AT and SR in May 2014 and found the numerical correspondence between AT error (ATE and SR. This corresponding relation was used to calculate real-time ATE according to real-time SR and to correct the error of AT in other months.

  5. Corrections to the Mann et al. (1998) proxy data base and northern hemispheric average temperature series

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, S.; McKitrick, R. [University of Guelph, Ontario (Canada). Dept. of Economics

    2003-11-01

    The data set of proxies of past climate used in Mann, Bradley and Hughes (1998, 'MBH98' hereafter) for the estimation of temperatures from 1400 to 1980 contains collation errors, unjustifiable truncation or extrapolation of source data, obsolete data, geographical location errors, incorrect calculation of principal components and other quality control defects. We detail these errors and defects. We then apply MBH98 methodology to the construction of a Northern Hemisphere average temperature index for the 1400-1980 period, using corrected and updated source data. The major finding is that the values in the early 15th century exceed any values in the 20th century. The particular 'hockey stick' shape derived in the MBH98 proxy construction - a temperature index that decreases slightly between the early 15th century and early 20th century and then increases dramatically up to 1980 - is primarily an artefact of poor data handling, obsolete data and incorrect calculation of principal components. (Author)

  6. Ionospheric correction based on ingestion of global ionospheric maps into the NeQuick 2 model.

    Science.gov (United States)

    Yu, Xiao; She, Chengli; Zhen, Weimin; Bruno, Nava; Liu, Dun; Yue, Xinan; Ou, Ming; Xu, Jisheng

    2015-01-01

    The global ionospheric maps (GIMs), generated by Jet Propulsion Laboratory (JPL) and Center for Orbit Determination in Europe (CODE) during a period over 13 years, have been adopted as the primary source of data to provide global ionospheric correction for possible single frequency positioning applications. The investigation aims to assess the performance of new NeQuick model, NeQuick 2, in predicting global total electron content (TEC) through ingesting the GIMs data from the previous day(s). The results show good performance of the GIMs-driven-NeQuick model with average 86% of vertical TEC error less than 10 TECU, when the global daily effective ionization indices (Az) versus modified dip latitude (MODIP) are constructed as a second order polynomial. The performance of GIMs-driven-NeQuick model presents variability with solar activity and behaves better during low solar activity years. The accuracy of TEC prediction can be improved further through performing a four-coefficient function expression of Az versus MODIP. As more measurements from earlier days are involved in the Az optimization procedure, the accuracy may decrease. The results also reveal that more efforts are needed to improve the NeQuick 2 model capabilities to represent the ionosphere in the equatorial and high-latitude regions. PMID:25815369

  7. Wall correction model for wind tunnels with open test section

    DEFF Research Database (Denmark)

    Sørensen, Jens Nørkær; Shen, Wen Zhong; Mikkelsen, Robert Flemming

    2006-01-01

    In the paper we present a correction model for wall interference on rotors of wind turbines or propellers in wind tunnels. The model, which is based on a one-dimensional momentum approach, is validated against results from CFD computations using a generalized actuator disc principle. In the model...... the exchange of axial momentum between the tunnel and the ambient room is represented by a simple formula, derived from actuator disc computations. The correction model is validated against Navier-Stokes computations of the flow about a wind turbine rotor. Generally, the corrections from the model are in very...... good agreement with the CFD computations, demonstrating that one-dimensional momentum theory is a reliable way of predicting corrections for wall interference in wind tunnels with closed as well as open cross sections....

  8. Operating room manager game

    NARCIS (Netherlands)

    Hans, Erwin W.; Nieberg, Tim

    2007-01-01

    The operating room (OR) department of a hospital forms the heart of the organization, where the single largest cost is incurred. This document presents and reports on the “Operating Room Manager Game,” developed to give insight into managing a large hospital's OR department at various levels of cont

  9. The Virtual Dressing Room

    DEFF Research Database (Denmark)

    Holte, Michael Boelstoft; Gao, Yi; Petersson, Eva

    2015-01-01

    This paper presents the design and evaluation of a usability and user experience test of a virtual dressing room. First, we motivate and introduce our recent developed prototype of a virtual dressing room. Next, we present the research and test design grounded in related usability and user experi...

  10. Predicting Acoustics in Class Rooms

    DEFF Research Database (Denmark)

    Christensen, Claus Lynge; Rindel, Jens Holger

    2005-01-01

    Typical class rooms have fairly simple geometries, even so room acoustics in this type of room is difficult to predict using today's room acoustic computer modeling software. The reasons why acoustics of class rooms are harder to predict than acoustics of complicated concert halls might be explai......Typical class rooms have fairly simple geometries, even so room acoustics in this type of room is difficult to predict using today's room acoustic computer modeling software. The reasons why acoustics of class rooms are harder to predict than acoustics of complicated concert halls might...... with surface scattering is presented. Each of the two scattering effects is modeled as frequency dependent functions....

  11. Improved UTE-based attenuation correction for cranial PET-MR using dynamic magnetic field monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Aitken, A. P.; Giese, D.; Tsoumpas, C.; Schleyer, P.; Kozerke, S.; Prieto, C.; Schaeffter, T., E-mail: Tobias.Schaeffter@kcl.ac.uk [Department of Biomedical Engineering, Division of Imaging Sciences and Biomedical Engineering, King' s College London, King' s Health Partners, St. Thomas Hospital, London SE1 7EH (United Kingdom)

    2014-01-15

    Purpose: Ultrashort echo time (UTE) MRI has been proposed as a way to produce segmented attenuation maps for PET, as it provides contrast between bone, air, and soft tissue. However, UTE sequences require samples to be acquired during rapidly changing gradient fields, which makes the resulting images prone to eddy current artifacts. In this work it is demonstrated that this can lead to misclassification of tissues in segmented attenuation maps (AC maps) and that these effects can be corrected for by measuring the true k-space trajectories using a magnetic field camera. Methods: The k-space trajectories during a dual echo UTE sequence were measured using a dynamic magnetic field camera. UTE images were reconstructed using nominal trajectories and again using the measured trajectories. A numerical phantom was used to demonstrate the effect of reconstructing with incorrect trajectories. Images of an ovine leg phantom were reconstructed and segmented and the resulting attenuation maps were compared to a segmented map derived from a CT scan of the same phantom, using the Dice similarity measure. The feasibility of the proposed method was demonstrated inin vivo cranial imaging in five healthy volunteers. Simulated PET data were generated for one volunteer to show the impact of misclassifications on the PET reconstruction. Results: Images of the numerical phantom exhibited blurring and edge artifacts on the bone–tissue and air–tissue interfaces when nominal k-space trajectories were used, leading to misclassification of soft tissue as bone and misclassification of bone as air. Images of the tissue phantom and thein vivo cranial images exhibited the same artifacts. The artifacts were greatly reduced when the measured trajectories were used. For the tissue phantom, the Dice coefficient for bone in MR relative to CT was 0.616 using the nominal trajectories and 0.814 using the measured trajectories. The Dice coefficients for soft tissue were 0.933 and 0.934 for the

  12. Evaluation of training programs and entry-level qualifications for nuclear-power-plant control-room personnel based on the systems approach to training

    Energy Technology Data Exchange (ETDEWEB)

    Haas, P M; Selby, D L; Hanley, M J; Mercer, R T

    1983-09-01

    This report summarizes results of research sponsored by the US Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research to initiate the use of the Systems Approach to Training in the evaluation of training programs and entry level qualifications for nuclear power plant (NPP) personnel. Variables (performance shaping factors) of potential importance to personnel selection and training are identified, and research to more rigorously define an operationally useful taxonomy of those variables is recommended. A high-level model of the Systems Approach to Training for use in the nuclear industry, which could serve as a model for NRC evaluation of industry programs, is presented. The model is consistent with current publically stated NRC policy, with the approach being followed by the Institute for Nuclear Power Operations, and with current training technology. Checklists to be used by NRC evaluators to assess training programs for NPP control-room personnel are proposed which are based on this model.

  13. Hole-exciton interaction induced high field decay of magneto-electroluminescence in Alq3-based organic light-emitting diodes at room temperature

    International Nuclear Information System (INIS)

    The magnetic field effects on the electroluminescence of aluminium tris-(8-hydroxyqinoline) (Alq3) based organic light emitting diodes have been investigated by varying the electron/hole ratio in the emissive layer. Experimental results reveal that a negative high field effect in the magneto-electroluminescence (MEL) can be found in devices with very low triplet exciton concentration at room temperature. This suggests triplet-triplet annihilation cannot be used to explain the negative high field MEL in the Alq3 system. Our results suggest that hole-exciton interaction may be the origin of the negative high field MEL and also, in parallel with this interaction, there is also the more common positive high field process occurring which has been tentatively attributed to electron-exciton interactions. The competition between these different processes decides the final shape of the MEL at high fields

  14. Evaluation of training programs and entry-level qualifications for nuclear-power-plant control-room personnel based on the systems approach to training

    International Nuclear Information System (INIS)

    This report summarizes results of research sponsored by the US Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research to initiate the use of the Systems Approach to Training in the evaluation of training programs and entry level qualifications for nuclear power plant (NPP) personnel. Variables (performance shaping factors) of potential importance to personnel selection and training are identified, and research to more rigorously define an operationally useful taxonomy of those variables is recommended. A high-level model of the Systems Approach to Training for use in the nuclear industry, which could serve as a model for NRC evaluation of industry programs, is presented. The model is consistent with current publically stated NRC policy, with the approach being followed by the Institute for Nuclear Power Operations, and with current training technology. Checklists to be used by NRC evaluators to assess training programs for NPP control-room personnel are proposed which are based on this model

  15. Hole-exciton interaction induced high field decay of magneto-electroluminescence in Alq{sub 3}-based organic light-emitting diodes at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Tingting; Holford, D. F.; Gu, Hang; Kreouzis, T. [Materials Research Institute and School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Zhang, Sijie, E-mail: Sijie.zhang@scu.edu.cn, E-mail: w.gillin@qmul.ac.uk [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Gillin, W. P., E-mail: Sijie.zhang@scu.edu.cn, E-mail: w.gillin@qmul.ac.uk [Materials Research Institute and School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China)

    2016-01-11

    The magnetic field effects on the electroluminescence of aluminium tris-(8-hydroxyqinoline) (Alq{sub 3}) based organic light emitting diodes have been investigated by varying the electron/hole ratio in the emissive layer. Experimental results reveal that a negative high field effect in the magneto-electroluminescence (MEL) can be found in devices with very low triplet exciton concentration at room temperature. This suggests triplet-triplet annihilation cannot be used to explain the negative high field MEL in the Alq{sub 3} system. Our results suggest that hole-exciton interaction may be the origin of the negative high field MEL and also, in parallel with this interaction, there is also the more common positive high field process occurring which has been tentatively attributed to electron-exciton interactions. The competition between these different processes decides the final shape of the MEL at high fields.

  16. A high performance hydrogen sulfide gas sensor based on porous α-Fe2O3 operates at room-temperature

    International Nuclear Information System (INIS)

    Highlights: • Novel porous α-Fe2O3 nanoparticles were prepared by a facile hydrothermal method. • The sensor based on porous α-Fe2O3 exhibits high sensitivity towards H2S gas. • The detection limit towards H2S gas was as low as 50 ppb at room temperature. • The sensor exhibits excellent selectivity against other toxic and noxious gases. - Abstract: Porous α-Fe2O3 nanoparticles were synthesized by simple annealing of β-FeOOH precursor derived from a facile hydrothermal route, the structures and morphologies of the as-prepared product were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the average crystallite size of the obtained porous α-Fe2O3 was 34 nm and exits numerous irregularly distributed pores with a diameter varying from 2 nm to 10 nm on the particle surface. The gas-sensing properties of the sensor based on porous α-Fe2O3 nanoparticles were investigated, and the result showed that the sensor exhibited a high performance in hydrogen sulfide (H2S) detection at room temperature. The highest sensitivity reached 38.4 for 100 ppm H2S, and the detection limit was as low as 50 ppb. In addition, the response of the sensor towards other gases including C2H5OH, CO, H2 and NH3 indicates the sensor has an excellent selectivity to detection H2S gas. Finally, the sensing mechanism of the sensor towards H2S was also discussed

  17. A high performance hydrogen sulfide gas sensor based on porous α-Fe{sub 2}O{sub 3} operates at room-temperature

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yanwu; Chen, Weimei; Zhang, Shouchao; Kuang, Zhong; Ao, Dongyi [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, 610054 (China); Alkurd, Nooraldeen Rafat; Zhou, Weilie [Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148 (United States); Liu, Wei [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, 610054 (China); Shen, Wenzhong [Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001 (China); Li, Zhijie, E-mail: zhijieli@uestc.edu.cn [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, 610054 (China)

    2015-10-01

    Highlights: • Novel porous α-Fe{sub 2}O{sub 3} nanoparticles were prepared by a facile hydrothermal method. • The sensor based on porous α-Fe{sub 2}O{sub 3} exhibits high sensitivity towards H{sub 2}S gas. • The detection limit towards H{sub 2}S gas was as low as 50 ppb at room temperature. • The sensor exhibits excellent selectivity against other toxic and noxious gases. - Abstract: Porous α-Fe{sub 2}O{sub 3} nanoparticles were synthesized by simple annealing of β-FeOOH precursor derived from a facile hydrothermal route, the structures and morphologies of the as-prepared product were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the average crystallite size of the obtained porous α-Fe{sub 2}O{sub 3} was 34 nm and exits numerous irregularly distributed pores with a diameter varying from 2 nm to 10 nm on the particle surface. The gas-sensing properties of the sensor based on porous α-Fe{sub 2}O{sub 3} nanoparticles were investigated, and the result showed that the sensor exhibited a high performance in hydrogen sulfide (H{sub 2}S) detection at room temperature. The highest sensitivity reached 38.4 for 100 ppm H{sub 2}S, and the detection limit was as low as 50 ppb. In addition, the response of the sensor towards other gases including C{sub 2}H{sub 5}OH, CO, H{sub 2} and NH{sub 3} indicates the sensor has an excellent selectivity to detection H{sub 2}S gas. Finally, the sensing mechanism of the sensor towards H{sub 2}S was also discussed.

  18. Fast rendering of scanned room geometries

    DEFF Research Database (Denmark)

    Olesen, Søren Krarup; Markovic, Milos; Hammershøi, Dorte

    2014-01-01

    Room acoustics are rendered in Virtual Realities based on models of the real world. These are typically rather coarse representations of the true geometry resulting in room impulse responses with a lack of natural detail. This problem can be overcome by using data scanned by sensors, such as e.g....

  19. Radiometric Non-Uniformity Characterization and Correction of Landsat 8 OLI Using Earth Imagery-Based Techniques

    Directory of Open Access Journals (Sweden)

    Frank Pesta

    2014-12-01

    Full Text Available Landsat 8 is the first satellite in the Landsat mission to acquire spectral imagery of the Earth using pushbroom sensor instruments. As a result, there are almost 70,000 unique detectors on the Operational Land Imager (OLI alone to monitor. Due to minute variations in manufacturing and temporal degradation, every detector will exhibit a different behavior when exposed to uniform radiance, causing a noticeable striping artifact in collected imagery. Solar collects using the OLI’s on-board solar diffuser panels are the primary method of characterizing detector level non-uniformity. This paper reports on an approach for using a side-slither maneuver to estimate relative detector gains within each individual focal plane module (FPM in the OLI. A method to characterize cirrus band detector-level non-uniformity using deep convective clouds (DCCs is also presented. These approaches are discussed, and then, correction results are compared with the diffuser-based method. Detector relative gain stability is assessed using the side-slither technique. Side-slither relative gains were found to correct streaking in test imagery with quality comparable to diffuser-based gains (within 0.005% for VNIR/PAN; 0.01% for SWIR and identified a 0.5% temporal drift over a year. The DCC technique provided relative gains that visually decreased striping over the operational calibration in many images.

  20. Distributed Localization Algorithm for Wireless Sensor Network Based on Multidimensional Scaling and the Shortest Path Distance Correction

    Institute of Scientific and Technical Information of China (English)

    DING Yingqiang; DU Liufeng; YANG Ting; SUN Yugeng

    2009-01-01

    Sensor localization is crucial for the configuration and applications of wireless sensor network (WSN). A novel distributed localization algorithm, MDS-DC was proposed for wireless sensor network based on multidi-mensional scaling (MDS) and the shortest path distance correction. In MDS-DC, several local positioning regions with reasonable distribution were firstly constructed by an adaptive search algorithm, which ensures the mergence between the local relative maps of the adjacent local position regions and can reduce the number of common nodes in the network. Then, based on the relationships between the estimated distances and actual distances of anchors, the distance estimation vectors of sensors around anchors were corrected in each local positioning region. During the computations of the local relative coordinates, an iterative process, which is the combination of classical MDS algorithm and SMACOF algorithm, was applied. Finally, the global relative positions or absolute positions of sen-sors were obtained through merging the relative maps of all local positioning regions. Simulation results show that MDS-DC has better performances in positioning precision, energy efficiency and robustness to range error, which can meet the requirements of applications for sensor localization in WSN.

  1. Visual-based simultaneous localization and mapping and global positioning system correction for geo-localization of a mobile robot

    International Nuclear Information System (INIS)

    This paper introduces an approach combining visual-based simultaneous localization and mapping (V-SLAM) and global positioning system (GPS) correction for accurate multi-sensor localization of an outdoor mobile robot in geo-referenced maps. The proposed framework combines two extended Kalman filters (EKF); the first one, referred to as the integration filter, is dedicated to the improvement of the GPS localization based on data from an inertial navigation system and wheels' encoders. The second EKF implements the V-SLAM process. The linear and angular velocities in the dynamic model of the V-SLAM EKF filter are given by the GPS/INS/Encoders integration filter. On the other hand, the output of the V-SLAM EKF filter is used to update the dynamics estimation in the integration filter and therefore the geo-referenced localization. This solution increases the accuracy and the robustness of the positioning during GPS outage and allows SLAM in less featured environments

  2. Physically Gelled Room-Temperature Ionic Liquid-Based Composite Membranes for CO2/N-2 Separation: Effect of Composition and Thickness on Membrane Properties and Performance

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, PT; Voss, BA; Wiesenauer, EF; Gin, DL; Nobe, RD

    2013-07-03

    An aspartame-based, low molecular-weight organic gelator (LMOG) was used to form melt-infused and composite membranes with two different imidazolium-based room-temperature ionic liquids (RTILs) for CO2 separation from N-2. Previous work demonstrated that LMOGs can gel RTILs at low, loading levels, and this aspartame-based LMOG was selected because it has been reported to gel a large number of RTILs. The imidazolium-based RTILs were used because of their inherent good properties for CO2/light gas separations. Analysis of the resulting bulk RTIL/LMOG physical gels showed that these materials have high sol-gel transition temperatures (ca. 135 degrees C) suitable for flue gas applications. Gas permeabilities and burst pressure measurements of thick, melt infused membranes revealed a trade-off between high CO2 permeabilities and good mechanical stability as a function of the LMOG loading. Defect-free, composite membranes of the gelled RTILs were successfully fabricated by choosing an appropriate porous membrane support (hydrophobic PTFE) using a suitable coating technique (roller coating). The thicknesses of the applied composite gel layers ranged from 10.3 to 20.7 mu m, which represents an order of magnitude decrease in active layer thickness, compared to the original melt-infused gel RTIL membranes.

  3. Prediction of the enthalpies of vaporization for room-temperature ionic liquids: Correlations and a substitution-based additive scheme

    Energy Technology Data Exchange (ETDEWEB)

    Kabo, Gennady J. [Chemistry Faculty and Research Institute for Physical Chemical Problems, Belarusian State University, Leningradskaya 14, 220030 Minsk (Belarus); Paulechka, Yauheni U., E-mail: paulechka@gmail.com [Chemistry Faculty and Research Institute for Physical Chemical Problems, Belarusian State University, Leningradskaya 14, 220030 Minsk (Belarus); Zaitsau, Dzmitry H. [Department of Physical Chemistry, University of Rostock, Dr-Lorenz-Weg. 1, 18059 Rostock (Germany); Department of Physical Chemistry, Kazan Federal University, Kremlevskaya str. 18, 420008 Kazan (Russian Federation); Firaha, Alena S. [Chemistry Faculty and Research Institute for Physical Chemical Problems, Belarusian State University, Leningradskaya 14, 220030 Minsk (Belarus)

    2015-06-10

    Highlights: • The available literature data on Δ{sub l}{sup g}H for ionic liquids were analyzed. • Correlation equations for Δ{sub l}{sup g}H were derived using symbolic regression. • A substitution-based incremental scheme for Δ{sub l}{sup g}H was developed. • The proposed scheme has an advantage over the existing predictive procedures. - Abstract: The literature data on the enthalpies of vaporization for aprotic ionic liquids (ILs) published by the end of May 2014 were analyzed and the most reliable Δ{sub l}{sup g}H{sub m} values were derived for 68 ILs. The selected enthalpies of vaporization were correlated with density and surface tension using symbolic regression and a number of effective correlation equations were proposed. The substitution-based incremental scheme for prediction of the enthalpies of vaporization of imidazolium, pyridinium and pyrrolidinium ILs was developed. The standard error of the regression for the developed scheme is significantly lower than that for the atom-based group-contribution schemes proposed earlier.

  4. Accurate mass error correction in liquid chromatography time-of-flight mass spectrometry based metabolomics

    NARCIS (Netherlands)

    Mihaleva, V.V.; Vorst, O.F.J.; Maliepaard, C.A.; Verhoeven, H.A.; Vos, de C.H.; Hall, R.D.; Ham, van R.C.H.J.

    2008-01-01

    Compound identification and annotation in (untargeted) metabolomics experiments based on accurate mass require the highest possible accuracy of the mass determination. Experimental LC/TOF-MS platforms equipped with a time-to-digital converter (TDC) give the best mass estimate for those mass signals

  5. Image artifacts from MR-based attenuation correction in clinical, whole-body PET/MRI

    DEFF Research Database (Denmark)

    Keller, Sune H; Holm, Søren; Hansen, Adam E;

    2013-01-01

    Integrated whole-body PET/MRI tomographs have become available. PET/MR imaging has the potential to supplement, or even replace combined PET/CT imaging in selected clinical indications. However, this is true only if methodological pitfalls and image artifacts arising from novel MR-based attenuation...

  6. Using Structure-Based Organic Chemistry Online Tutorials with Automated Correction for Student Practice and Review

    Science.gov (United States)

    O'Sullivan, Timothy P.; Hargaden, Gra´inne C.

    2014-01-01

    This article describes the development and implementation of an open-access organic chemistry question bank for online tutorials and assessments at University College Cork and Dublin Institute of Technology. SOCOT (structure-based organic chemistry online tutorials) may be used to supplement traditional small-group tutorials, thereby allowing…

  7. Development of new tip-loss corrections based on vortex theory and vortex methods

    DEFF Research Database (Denmark)

    Branlard, Emmanuel Simon Pierre; Gaunaa, Mac

    2014-01-01

    A new analytical formulation of the tip-loss factor is established based on helical vortex lament solutions. The derived tip-loss factor can be applied to wind-turbines, propellers or other rotary wings. Similar numerical formulations are used to assess the influence of wake expansion on tip...

  8. Improving quantitative dosimetry in (177)Lu-DOTATATE SPECT by energy window-based scatter corrections

    DEFF Research Database (Denmark)

    de Nijs, Robin; Lagerburg, Vera; Klausen, Thomas L;

    2014-01-01

    PURPOSE: Patient-specific dosimetry of lutetium-177 ((177)Lu)-DOTATATE treatment in neuroendocrine tumours is important, because uptake differs across patients. Single photon emission computer tomography (SPECT)-based dosimetry requires a conversion factor between the obtained counts and the acti...

  9. RILIS laser room

    CERN Multimedia

    2016-01-01

    Footage of the RILIS laser room at ISOLDE. The Resonance Ionization Laser Ion Source (RILIS) is a chemically selective ion source which relies on resonant excitation of atomic transitions using tunable laser radiation. This video shows you the laser table with the different lenses and optics as well as an overview of the RILIS laser setup. It also shows laser light with different colors and operation by the RILIS laser experts. The last part of the video shows you the laser path from the RILIS laser room into the ISOLDE GPS separator room where it enters the GPS separator magnet.

  10. RILIS laser room HD

    CERN Multimedia

    2016-01-01

    Footage of the RILIS laser room at ISOLDE. The Resonance Ionization Laser Ion Source (RILIS) is a chemically selective ion source which relies on resonant excitation of atomic transitions using tunable laser radiation. This video shows you the laser table with the different lenses and optics as well as an overview of the RILIS laser setup. It also shows laser light with different colors and operation by the RILIS laser experts. The last part of the video shows you the laser path from the RILIS laser room into the ISOLDE GPS separator room where it enters the GPS separator magnet.

  11. Emission-based estimation of lung attenuation coefficients for attenuation correction in time-of-flight PET/MR

    International Nuclear Information System (INIS)

    In standard segmentation-based MRI-guided attenuation correction (MRAC) of PET data on hybrid PET/MRI systems, the inter/intra-patient variability of linear attenuation coefficients (LACs) is ignored owing to the assignment of a constant LAC to each tissue class. This can lead to PET quantification errors, especially in the lung regions. In this work, we aim to derive continuous and patient-specific lung LACs from time-of-flight (TOF) PET emission data using the maximum likelihood reconstruction of activity and attenuation (MLAA) algorithm. The MLAA algorithm was constrained for estimation of lung LACs only in the standard 4-class MR attenuation map using Gaussian lung tissue preference and Markov random field smoothness priors. MRAC maps were derived from segmentation of CT images of 19 TOF-PET/CT clinical studies into background air, lung, soft tissue and fat tissue classes, followed by assignment of predefined LACs of 0, 0.0224, 0.0864 and 0.0975 cm−1, respectively. The lung LACs of the resulting attenuation maps were then estimated from emission data using the proposed MLAA algorithm. PET quantification accuracy of MRAC and MLAA methods was evaluated against the reference CT-based AC method in the lungs, lesions located in/near the lungs and neighbouring tissues. The results show that the proposed MLAA algorithm is capable of retrieving lung density gradients and compensate fairly for respiratory-phase mismatch between PET and corresponding attenuation maps. It was found that the mean of the estimated lung LACs generally follow the trend of the reference CT-based attenuation correction (CTAC) method. Quantitative analysis revealed that the MRAC method resulted in average relative errors of  −5.2   ±   7.1% and  −6.1   ±   6.7% in the lungs and lesions, respectively. These were reduced by the MLAA algorithm to  −0.8   ±   6.3% and  −3.3   ±   4.7%, respectively. In conclusion, we

  12. Spelling Correction in Context

    OpenAIRE

    Pinot, Guillaume; Enguehard, Chantal

    2005-01-01

    International audience Spelling checkers, frequently used nowadays, do not allow to correct real-word errors. Thus, the erroneous replacement of dessert by desert is not detected. We propose in this article an algorithm based on the examination of the context of words to correct this kind of spelling errors. This algorithm uses a training on a raw corpus.

  13. Determination of human IgG by solid substrate room temperature phosphorescence immunoassay based on an antibody labeled with nanoparticles containing dibromofluorescein luminescent molecules

    International Nuclear Information System (INIS)

    Luminescent silicon dioxide nano-particles with size of 20 nm, which containing dibromofluorescein (D) were synthesized by sol-gel method (symbolized by D-SiO2).The particles can emit intense and stable room temperature phosphorescence signal on polyamide membrane when Pb(Ac)2 was used as a heavy atom perturber. The λexmax/λemmax was 457/622 nm. Our research indicated that the specific immune reaction between goat-anti-human IgG antibody labeled with D-SiO2 and human IgG could be carried out on polyamide membrane quantitatively, and the phosphorescence intensity of the particle was enhanced after the immunoreactions. Thus a new method of solid substrate room temperature phosphorescence immunoassay (SS-RTP-IA) for the determination of human IgG was established basing on antibody labeled with the D-SiO2 nanoparticles. The linear range of this method was 0.0624-20.0 pg human IgG spot-1 (corresponding concentration: 0.156-50.0 ng ml-1, the sample volume: 0.40 μl spot-1) with a limit of detection (LD) as 0.018 pg spot-1, and the regression equation of working curve was ΔIp = 7.201 mIgG (pg spot-1) + 82.57. Samples containing 0.156 and 50.0 ng ml-1 of IgG were measured repeatedly for 11 times and R.S.D.s were 4.1 and 3.4%, respectively. Results showed that this method had the merits as sensitive, accurate and precise

  14. Determination of human IgG by solid substrate room temperature phosphorescence immunoassay based on an antibody labeled with nanoparticles containing Rhodamine 6G luminescent molecules

    Science.gov (United States)

    Jia-Ming, Liu; hui, Zhu Guo; Aihong, Wu; Pingping, Li; Huanhuan, Xu; Li, Long-Di; Liu, Zhen-bo

    2005-03-01

    Luminescent silicon dioxide nanoparticles (R-SiO 2) with size of 50 nm containing Rhodamine 6G (R) were synthesized by sol-gel method. In the presence of Pb(Ac) 2 as a heavy atom perturber, the particle can emit intense and stable room temperature phosphorescence signal of R, respectively, on polyamide membrane, with the λexmax/λemmax=470/635 nm for R. Our research indicates that the specific immune reaction between goat-anti-human IgG antibody labeled with R-SiO 2 and human IgG can be carried on polyamide membrane quantitatively, and the phosphorescence intensity was enhanced after the immunoreactions. Thus, a new method of solid substrate room temperature phosphorescence immunoassay (SS-RTP-IA) for the determination of human IgG was established basing on antibody labeled with the nanoparticles containing binary luminescent molecules. The linear range of this method is 0.0624-20.0 pg spot -1 of human IgG (corresponding concentration, 0.156-50.0 ng mL -1; sample volume, 0.40 μL spot -1). The regression equations of working curves are Δ Ip = 88.16. + 16.79m IgG (pg spot -1) (485/646 nm, r = 0.9997). Detection limits calculated by 3Sb/k are 0.017 pg spot -1. For samples containing 0.156 and 50.0 ng mL -1 of IgG, we measured repeatedly for 11 times, RSDs are 3.9 and 2.8%, respectively. This method is sensitive, accurate and of high precision.

  15. Scattering correction based on regularization de-convolution for Cone-Beam CT

    CERN Document Server

    Xie, Shi-peng

    2016-01-01

    In Cone-Beam CT (CBCT) imaging systems, the scattering phenomenon has a significant impact on the reconstructed image and is a long-lasting research topic on CBCT. In this paper, we propose a simple, novel and fast approach for mitigating scatter artifacts and increasing the image contrast in CBCT, belonging to the category of convolution-based method in which the projected data is de-convolved with a convolution kernel. A key step in this method is how to determine the convolution kernel. Compared with existing methods, the estimation of convolution kernel is based on bi-l1-l2-norm regularization imposed on both the intermediate the known scatter contaminated projection images and the convolution kernel. Our approach can reduce the scatter artifacts from 12.930 to 2.133.

  16. Irinotecan-based regimens for recurrent glioblastoma multiforme: [corrected] a systematic review.

    Science.gov (United States)

    Abdel-Rahman, Omar; Fouad, Mona

    2015-01-01

    This systematic review aims to assess irinotecan-based salvage regimens for patients with recurrent glioblastoma multiforme (GBM) beyond first line treatment. Eligible trials were identified using databases search and 25 studies were included in the final analysis. Among the 25 studies, PFS-6 rate was reported in 15 studies and it ranged from 16% to 63%. Median PFS was reported in 18 studies and it ranged from 1 to 7.6 months. While for median OS, it was reported in 17 studies and it ranged from 5.8 months to 17.9 months. The available data suggests that routine use of irinotecan-based salvage regimens cannot be recommended outside the setting of well-controlled prospective randomized studies investigating novel combinations of irinotecan. PMID:26469869

  17. Correcting Laser-Based Water Stable Isotope Readings Biased by Carrier Gas Changes.

    Science.gov (United States)

    Gralher, Benjamin; Herbstritt, Barbara; Weiler, Markus; Wassenaar, Leonard I; Stumpp, Christine

    2016-07-01

    Recently, laser-based water stable isotope spectrometers have become popular as they enable previously impossible approaches of environmental observations. Consequently, they have been subjected to increasingly heterogeneous atmospheric conditions. However, there is still a severe lack of data on the impact of nonstandardized gas matrices on analyzer performances. Against this background, we investigated the influence of changing proportions of N2, O2, and CO2 in the carrier gas on the isotope measurements of a typical laser-based water stable isotope analyzer (Picarro L2120-i). We combined environmentally relevant mixtures of N2, O2, and CO2 with referenced, flash-evaporated water and found that isotope readings of the same water were altered by up to +14.57‰ for δ(18)O and -35.9‰ for δ(2)H. All tested relationships between carrier gas changes and respective isotope readings were strongly linearly correlated (R(2) > 0.99). Furthermore, an analyzer-measured variable allowed for reliable postcorrection of the biased isotope readings, which we additionally tested on field data. Our findings are of importance for environmental data obtained by analyzers based on the same technology. They are relevant for assays where inconsistent gas matrices or a mismatch in this regard between unknown and reference analyses cannot be excluded, which is in particular common when investigating the soil-vegetation-atmosphere continuum. PMID:27291718

  18. Tritium Removal System for Airtight Room in High-flux Advanced Neutron Application Reactor (HANARO) - 12110

    International Nuclear Information System (INIS)

    An Airtight room was installed to prevent the diffusion of tritium from the instrument room to other areas in HANARO. It was isolated by a robust structure and the inside was closed tightly. A Tritium removal system located outside the instrument room was connected to the airtight room to lower the tritium concentration when the workers enter the room for maintenance of the instruments. The tritium concentration and the dew point in the airtight room were continuously measured during the operation of the tritium removal system. The data were analyzed by using a model. There was a difference between the measured tritium concentration and the one obtained by the model. It is believed that the difference is due to the change of the generation rate of tritium which would increase as the dew point becomes lower. Based on this assumption, the previous equation was revised to better express the performance of the tritium removal system. It was re-estimated that the change of tritium concentration in an airtight room could be predicted well by using a model and equation proposed in the previous study. It was confirmed that there was a definite difference between the measured tritium concentration and the one obtained by equation from the model. It is believed that the difference is due to the change of the generation rate of tritium which would increase as the dew point becomes lower. Based on this assumption, the generation rate of tritium was controlled to have higher value and the change of tritium concentration in airtight room could be more correctly predicted. By using the revised equation, the tritium removal system would be operated more effectively. (authors)

  19. Guided filter and adaptive learning rate based non-uniformity correction algorithm for infrared focal plane array

    Science.gov (United States)

    Sheng-Hui, Rong; Hui-Xin, Zhou; Han-Lin, Qin; Rui, Lai; Kun, Qian

    2016-05-01

    Imaging non-uniformity of infrared focal plane array (IRFPA) behaves as fixed-pattern noise superimposed on the image, which affects the imaging quality of infrared system seriously. In scene-based non-uniformity correction methods, the drawbacks of ghosting artifacts and image blurring affect the sensitivity of the IRFPA imaging system seriously and decrease the image quality visibly. This paper proposes an improved neural network non-uniformity correction method with adaptive learning rate. On the one hand, using guided filter, the proposed algorithm decreases the effect of ghosting artifacts. On the other hand, due to the inappropriate learning rate is the main reason of image blurring, the proposed algorithm utilizes an adaptive learning rate with a temporal domain factor to eliminate the effect of image blurring. In short, the proposed algorithm combines the merits of the guided filter and the adaptive learning rate. Several real and simulated infrared image sequences are utilized to verify the performance of the proposed algorithm. The experiment results indicate that the proposed algorithm can not only reduce the non-uniformity with less ghosting artifacts but also overcome the problems of image blurring in static areas.

  20. Wavelet-based denoising of the Fourier metric in real-time wavefront correction for single molecule localization microscopy

    Science.gov (United States)

    Tehrani, Kayvan Forouhesh; Mortensen, Luke J.; Kner, Peter

    2016-03-01

    Wavefront sensorless schemes for correction of aberrations induced by biological specimens require a time invariant property of an image as a measure of fitness. Image intensity cannot be used as a metric for Single Molecule Localization (SML) microscopy because the intensity of blinking fluorophores follows exponential statistics. Therefore a robust intensity-independent metric is required. We previously reported a Fourier Metric (FM) that is relatively intensity independent. The Fourier metric has been successfully tested on two machine learning algorithms, a Genetic Algorithm and Particle Swarm Optimization, for wavefront correction about 50 μm deep inside the Central Nervous System (CNS) of Drosophila. However, since the spatial frequencies that need to be optimized fall into regions of the Optical Transfer Function (OTF) that are more susceptible to noise, adding a level of denoising can improve performance. Here we present wavelet-based approaches to lower the noise level and produce a more consistent metric. We compare performance of different wavelets such as Daubechies, Bi-Orthogonal, and reverse Bi-orthogonal of different degrees and orders for pre-processing of images.

  1. A GPU-based finite-size pencil beam algorithm with 3D-density correction for radiotherapy dose calculation

    CERN Document Server

    Gu, Xuejun; Li, Jinsheng; Jia, Xun; Jiang, Steve B

    2011-01-01

    Targeting at developing an accurate and efficient dose calculation engine for online adaptive radiotherapy, we have implemented a finite size pencil beam (FSPB) algorithm with a 3D-density correction method on GPU. This new GPU-based dose engine is built on our previously published ultrafast FSPB computational framework [Gu et al. Phys. Med. Biol. 54 6287-97, 2009]. Dosimetric evaluations against MCSIM Monte Carlo dose calculations are conducted on 10 IMRT treatment plans with heterogeneous treatment regions (5 head-and-neck cases and 5 lung cases). For head and neck cases, when cavities exist near the target, the improvement with the 3D-density correction over the conventional FSPB algorithm is significant. However, when there are high-density dental filling materials in beam paths, the improvement is small and the accuracy of the new algorithm is still unsatisfactory. On the other hand, significant improvement of dose calculation accuracy is observed in all lung cases. Especially when the target is in the m...

  2. Operative correction of judoists’ training loads on the base of on-line monitoring of heart beats rate

    Directory of Open Access Journals (Sweden)

    Liu Yong Qiang

    2015-02-01

    Full Text Available Purpose: ensure increase of effectiveness of training process’s control by means of operative correction of training loads of different qualification judo wrestlers’ heart beats rate indicators. Material: the research was conducted on the base of Brest SCJSOR № 1. Judo wrestlers of different sport qualification (age 17-19 years old, n=15 participated in the research. Monitoring of judo wrestlers’ heart beats rate was carried out with the help of system “Polar”. Results: we have found factorial structure of functional fitness in every profile of sportsmen. Model characteristics of judo wrestlers were supplemented with the most important sides of functional fitness. Analysis of indicators of restoration effectiveness indicators (REI in both groups of judo wrestlers showed high level of organism’s responsiveness to training load of special and power orientation in comparison with speed power load. We have worked out algorithm of operative correction of training loads by indicators of heart beats rate in training process, depending on orientation and intensity of loads’ physiological influence on judo wrestler. Conclusions: Telemetric on-line monitoring of sportsman’s heart beats rate and calculation of REI permit to objectively assess effectiveness of training’s construction and of micro-cycle in total and detect in due time the trend to development of over-loading and failure of adaptation.

  3. Comments on "Synthesis aspects, structural, spectroscopic, antimicrobial and room temperature ferromagnetism of zinc iodide complex with Schiff based ligand" by K. Shakila and S. Kalainathan, Spectrochim. Acta 135 A (2015) 1059-1065

    Science.gov (United States)

    Srinivasan, Bikshandarkoil R.; Nadkarni, V. S.

    2016-06-01

    Shakila and Kalainathan report on the synthetic and structural aspects of a zinc iodide complex with Schiff based ligand, which exhibits room temperature ferromagnetism. In this comment, many points of criticism, concerning the characterization of this so called zinc iodide complex of Schiff based ligand are highlighted to prove that the title paper is completely erroneous.

  4. Conditions of Psychological Readiness of Pupils to Corrections in Cognitive Areas (Based on Reading)

    OpenAIRE

    Kirakosyan A. Kh.

    2014-01-01

    We present a comparative study of the conditions of formation of readiness for classes in students with high and low levels of a given cognitive skill (based on the reading actions). We compared conditions associated, on the one hand, with the child's understanding that his actions are not optimal, and with the work in the zone of proximal development, on the other, with the work in the area of actual skill development and child's satisfaction of the actions result. We assumed optimality of t...

  5. The Ringhals HSI and control room modernisation programme - the practical application of a contemporary user and HF based HSI design process

    International Nuclear Information System (INIS)

    The existing Ringhals 2 main control room and constituent HSI has now been in operation over approximately 30 years. It has been estimated that the plant's life expectancy can be extended a further 25 years, assuming that a comprehensive modernisation of the present R2 I and C systems is implemented. This paper is intended to provide the readers with a general overview of the modernisation programme initiated during 1999 and expected to be completed with the new MCR and HSI to be in operation during 2006. There are a number of aspects to the modernisation programme that may make it somewhat unique. Naturally the lessons learned during this programme may be of interest for other organisations discussing future plant modernisation Although we can naturally cite the conventional reasons for plant modernisation, one should not neglect other factors that at first glance may not be all that obvious. Such factors include the changing demographic trends in knowledge and training represented in the national educational processes in conjunction with the transition to digital technologies. Personnel expectations upon their future work places also play a role. Nor for that matter should issues such as personnel recruitment policies and organisational goals be underestimated in the design process. A critical aspect of the Ringhals modernisation programme that had to be tackled with was the design development process adopted for design specification, design development and design verification of the MCR and HSI solutions. From the outset Ringhals has pursued the goal of applying an integrated user and human factors (HF) based design approach in the modernisation process's design activities. Therefore user participation in the design process as well as the application of the NUREG 0711 HF Design Process Model and other suitable guidelines for HFE design processes has been a guiding principle. Ringhals possibly represents an interesting example of the practical application of

  6. Gyro Drift Correction for An Indirect Kalman Filter Based Sensor Fusion Driver

    Science.gov (United States)

    Lee, Chan-Gun; Dao, Nhu-Ngoc; Jang, Seonmin; Kim, Deokhwan; Kim, Yonghun; Cho, Sungrae

    2016-01-01

    Sensor fusion techniques have made a significant contribution to the success of the recently emerging mobile applications era because a variety of mobile applications operate based on multi-sensing information from the surrounding environment, such as navigation systems, fitness trackers, interactive virtual reality games, etc. For these applications, the accuracy of sensing information plays an important role to improve the user experience (UX) quality, especially with gyroscopes and accelerometers. Therefore, in this paper, we proposed a novel mechanism to resolve the gyro drift problem, which negatively affects the accuracy of orientation computations in the indirect Kalman filter based sensor fusion. Our mechanism focuses on addressing the issues of external feedback loops and non-gyro error elements contained in the state vectors of an indirect Kalman filter. Moreover, the mechanism is implemented in the device-driver layer, providing lower process latency and transparency capabilities for the upper applications. These advances are relevant to millions of legacy applications since utilizing our mechanism does not require the existing applications to be re-programmed. The experimental results show that the root mean square errors (RMSE) before and after applying our mechanism are significantly reduced from 6.3×10-1 to 5.3×10-7, respectively. PMID:27294941

  7. Gyro Drift Correction for An Indirect Kalman Filter Based Sensor Fusion Driver.

    Science.gov (United States)

    Lee, Chan-Gun; Dao, Nhu-Ngoc; Jang, Seonmin; Kim, Deokhwan; Kim, Yonghun; Cho, Sungrae

    2016-01-01

    Sensor fusion techniques have made a significant contribution to the success of the recently emerging mobile applications era because a variety of mobile applications operate based on multi-sensing information from the surrounding environment, such as navigation systems, fitness trackers, interactive virtual reality games, etc. For these applications, the accuracy of sensing information plays an important role to improve the user experience (UX) quality, especially with gyroscopes and accelerometers. Therefore, in this paper, we proposed a novel mechanism to resolve the gyro drift problem, which negatively affects the accuracy of orientation computations in the indirect Kalman filter based sensor fusion. Our mechanism focuses on addressing the issues of external feedback loops and non-gyro error elements contained in the state vectors of an indirect Kalman filter. Moreover, the mechanism is implemented in the device-driver layer, providing lower process latency and transparency capabilities for the upper applications. These advances are relevant to millions of legacy applications since utilizing our mechanism does not require the existing applications to be re-programmed. The experimental results show that the root mean square errors (RMSE) before and after applying our mechanism are significantly reduced from 6.3 × 10(-1) to 5.3 × 10(-7), respectively. PMID:27294941

  8. Gyro Drift Correction for An Indirect Kalman Filter Based Sensor Fusion Driver.

    Science.gov (United States)

    Lee, Chan-Gun; Dao, Nhu-Ngoc; Jang, Seonmin; Kim, Deokhwan; Kim, Yonghun; Cho, Sungrae

    2016-06-11

    Sensor fusion techniques have made a significant contribution to the success of the recently emerging mobile applications era because a variety of mobile applications operate based on multi-sensing information from the surrounding environment, such as navigation systems, fitness trackers, interactive virtual reality games, etc. For these applications, the accuracy of sensing information plays an important role to improve the user experience (UX) quality, especially with gyroscopes and accelerometers. Therefore, in this paper, we proposed a novel mechanism to resolve the gyro drift problem, which negatively affects the accuracy of orientation computations in the indirect Kalman filter based sensor fusion. Our mechanism focuses on addressing the issues of external feedback loops and non-gyro error elements contained in the state vectors of an indirect Kalman filter. Moreover, the mechanism is implemented in the device-driver layer, providing lower process latency and transparency capabilities for the upper applications. These advances are relevant to millions of legacy applications since utilizing our mechanism does not require the existing applications to be re-programmed. The experimental results show that the root mean square errors (RMSE) before and after applying our mechanism are significantly reduced from 6.3 × 10(-1) to 5.3 × 10(-7), respectively.

  9. A comparative study of Sterofundin and Ringer lactate based infusion protocol in scoliosis correction surgery

    Science.gov (United States)

    Sharma, Ashima; Yadav, Monu; Kumar, B. Rajesh; Lakshman, P. Sai; Iyenger, Raju; Ramchandran, Gopinath

    2016-01-01

    Background: A major change in anesthesia practice as regards to intraoperative infusion therapy is the present requirement. Switching over to balanced fluids can substantially decrease the incidence of lactic acidosis and hyperchloremic acidosis. The deleterious effects of unbalanced fluids are more recognizable during major surgeries. We prospectively studied the influence of Sterofundin (SF) and Ringer lactate (RL) on acid–base changes, hemodynamics, and readiness for extubation during scoliosis surgery. Subjects and Methods: Thirty consecutive children posted for scoliosis surgery were randomized to receive either RL (n = 15) or SF (n = 15) as intraoperative fluid at 10 mg/kg/h. Fluid boluses were added according to the study fluid algorithm. Arterial blood was sampled and analyzed at hourly intervals during surgery. Red blood cell transfusion was guided by hematocrit below 27. Patients were followed for 24 h postoperatively in the Intensive Care Unit. Results: There was no statistically significant difference in the volume of infused fluid (2400 ± 512 ml in Group RL and 2200 ± 640 ml in Group SF. There were no significant changes in pH of patients infused with SF. Statistically, significant higher lactate levels were seen in RL-infused group. The strong ion difference was decreased in both groups, but it normalized earlier with SF. Conclusions: SF-infused patients had nonremarkable changes in acid–base physiology in scoliosis surgery. PMID:27746547

  10. Gyro Drift Correction for An Indirect Kalman Filter Based Sensor Fusion Driver

    Directory of Open Access Journals (Sweden)

    Chan-Gun Lee

    2016-06-01

    Full Text Available Sensor fusion techniques have made a significant contribution to the success of the recently emerging mobile applications era because a variety of mobile applications operate based on multi-sensing information from the surrounding environment, such as navigation systems, fitness trackers, interactive virtual reality games, etc. For these applications, the accuracy of sensing information plays an important role to improve the user experience (UX quality, especially with gyroscopes and accelerometers. Therefore, in this paper, we proposed a novel mechanism to resolve the gyro drift problem, which negatively affects the accuracy of orientation computations in the indirect Kalman filter based sensor fusion. Our mechanism focuses on addressing the issues of external feedback loops and non-gyro error elements contained in the state vectors of an indirect Kalman filter. Moreover, the mechanism is implemented in the device-driver layer, providing lower process latency and transparency capabilities for the upper applications. These advances are relevant to millions of legacy applications since utilizing our mechanism does not require the existing applications to be re-programmed. The experimental results show that the root mean square errors (RMSE before and after applying our mechanism are significantly reduced from 6.3 × 10−1 to 5.3 × 10−7, respectively.

  11. Enhanced Monitoring of the Preterm Infant during Stabilisation in the Delivery Room

    Directory of Open Access Journals (Sweden)

    Daragh eFinn

    2016-03-01

    Full Text Available Monitoring of preterm infants in the delivery room remains limited. Current guidelines suggest that pulse oximetry should be available for all preterm infant deliveries, and that if intubated a colormetric carbon dioxide detector should provide verification of correct endotracheal tube placement. These two methods of assessment represent the extent of objective monitoring of the newborn commonly performed in the delivery room. Monitoring non-invasive ventilation effectiveness (either by capnography or respiratory function monitoring, and cerebral oxygenation (near infrared spectroscopy are becoming more common within research settings. In this article, we will review the different modalities available for cardio-respiratory and neuro-monitoring in the delivery room, and assess the current evidence base on their feasibility, strengths and limitations during preterm stabilisation.

  12. Preparation of the glucose sensor based on three-dimensional ordered macroporous gold film and room temperature ionic liquid

    Institute of Scientific and Technical Information of China (English)

    CHEN XiaoJun; XUAN Jie; JIANG LiPing; ZHU JunJie

    2009-01-01

    A novel type of glucose sensor was fabricated based on a glucose oxidase (GOD)-N,N-dimethtylformamide (DMF)-[BMIm][BF4]composites modified three-dimensional ordered macroporous (3DOM) gold film electrode.The immobilized GOD exhibits a pair of well-defined reversible peaks in 50 mM pH 7.0 phosphate buffer solutions (PBS),which could be attributed to the redox of flavin adenine dinucleotide (FAD) in GOD.The research results show that ionic liquid ([BMIm][BF_4]),DMF and 3DOM gold film are crucial for GOD to exhibit a pair of stable and reversible peaks.It is believed that the large active area of 3DOM gold film can increase the amount of immobilized GOD.Simultaneously,the application of IL enhances the stability of GOD and facilitates the electron transfer between GOD and the electrode.The synergetic effect of DMF can help the GOD to maintain its bioactivity better.GOD immobilized on the electrode exhibits the favorable electrocatalytic property to glucose,and the prepared sensor has a linear range from 10 to 125 nM with a detection limit of 3.3 nM at a signal-to-noise ratio of 30.The apparent K_m (Michaelis-Menten constant) for the enzymatic reaction is 0.018 mM.

  13. Preparation of the glucose sensor based on three-dimensional ordered macroporous gold film and room temperature ionic liquid

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A novel type of glucose sensor was fabricated based on a glucose oxidase(GOD)-N,N-dimethtylformamide(DMF)-[BMIm][BF4] composites modified three-dimensional ordered macroporous(3DOM) gold film electrode.The immobilized GOD exhibits a pair of well-defined reversible peaks in 50 mM pH 7.0 phosphate buffer solutions(PBS),which could be attributed to the redox of flavin adenine dinucleotide(FAD) in GOD.The research results show that ionic liquid([BMIm][BF4]),DMF and 3DOM gold film are crucial for GOD to exhibit a pair of stable and reversible peaks.It is believed that the large active area of 3DOM gold film can increase the amount of immobilized GOD.Simultaneously,the application of IL enhances the stability of GOD and facilitates the electron transfer between GOD and the electrode.The synergetic effect of DMF can help the GOD to maintain its bioactivity better.GOD immobilized on the electrode exhibits the favorable electrocatalytic property to glucose,and the prepared sensor has a linear range from 10 to 125 nM with a detection limit of 3.3 nM at a signal-to-noise ratio of 3σ.The apparent Km(Michaelis-Menten constant) for the enzymatic reaction is 0.018 mM.

  14. Analysis of measured data of human body based on error correcting frequency

    Science.gov (United States)

    Jin, Aiyan; Peipei, Gao; Shang, Xiaomei

    2014-04-01

    Anthropometry is to measure all parts of human body surface, and the measured data is the basis of analysis and study of the human body, establishment and modification of garment size and formulation and implementation of online clothing store. In this paper, several groups of the measured data are gained, and analysis of data error is gotten by analyzing the error frequency and using analysis of variance method in mathematical statistics method. Determination of the measured data accuracy and the difficulty of measured parts of human body, further studies of the causes of data errors, and summarization of the key points to minimize errors possibly are also mentioned in the paper. This paper analyses the measured data based on error frequency, and in a way , it provides certain reference elements to promote the garment industry development.

  15. The correction of vibration in frequency scanning interferometry based absolute distance measurement system for dynamic measurements

    Science.gov (United States)

    Lu, Cheng; Liu, Guodong; Liu, Bingguo; Chen, Fengdong; Zhuang, Zhitao; Xu, Xinke; Gan, Yu

    2015-10-01

    Absolute distance measurement systems are of significant interest in the field of metrology, which could improve the manufacturing efficiency and accuracy of large assemblies in fields such as aircraft construction, automotive engineering, and the production of modern windmill blades. Frequency scanning interferometry demonstrates noticeable advantages as an absolute distance measurement system which has a high precision and doesn't depend on a cooperative target. In this paper , the influence of inevitable vibration in the frequency scanning interferometry based absolute distance measurement system is analyzed. The distance spectrum is broadened as the existence of Doppler effect caused by vibration, which will bring in a measurement error more than 103 times bigger than the changes of optical path difference. In order to decrease the influence of vibration, the changes of the optical path difference are monitored by a frequency stabilized laser, which runs parallel to the frequency scanning interferometry. The experiment has verified the effectiveness of this method.

  16. Physiologically corrected coupled motion during gait analysis using a model-based approach.

    Science.gov (United States)

    Bonnechère, Bruno; Sholukha, Victor; Salvia, Patrick; Rooze, Marcel; Van Sint Jan, Serge

    2015-01-01

    Gait analysis is used in daily clinics for patients' evaluation and follow-up. Stereophotogrammetric devices are the most used tool to perform these analyses. Although these devices are accurate results must be analyzed carefully due to relatively poor reproducibility. One of the major issues is related to skin displacement artifacts. Motion representation is recognized reliable for the main plane of motion displacement, but secondary motions, or combined, are less reliable because of the above artifacts. Model-based approach (MBA) combining accurate joint kinematics and motion data was previously developed based on a double-step registration method. This study presents an extensive validation of this MBA method by comparing results with a conventional motion representation model. Thirty five healthy subjects participated to this study. Gait motion data were obtained from a stereophotogrammetric system. Plug-in Gait model (PiG) and MBA were applied to raw data, results were then compared. Range-of-motion, were computed for pelvis, hip, knee and ankle joints. Differences between PiG and MBA were then computed. Paired-sample t-tests were used to compare both methods. Normalized root-mean square errors were also computed. Shapes of the curves were compared using coefficient of multiple correlations. The MBA and PiG approaches shows similar results for the main plane of motion displacement but statistically significative discrepancies appear for the combined motions. MBA appear to be usable in applications (such as musculoskeletal modeling) requesting better approximations of the joints-of-interest thanks to the integration of validated joint mechanisms.

  17. Highly sensitive room temperature organic vapor sensor based on polybenzoxazine-derived carbon aerogel thin film composite

    Energy Technology Data Exchange (ETDEWEB)

    Thubsuang, Uthen [Materials Science and Engineering, School of Engineering and Resources, Walailak University, Nakhon Si Thammarat 80160 (Thailand); Sukanan, Darunee [The Petroleum and Petrochemical College and the Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Bangkok 10330 (Thailand); Sahasithiwat, Somboon [National Metal and Materials Technology Center, Thailand Science Park (TSP), Khlong Luang, Pathum Thani 12120 (Thailand); Wongkasemjit, Sujitra [The Petroleum and Petrochemical College and the Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Bangkok 10330 (Thailand); Chaisuwan, Thanyalak, E-mail: thanyalak.c@chula.ac.th [The Petroleum and Petrochemical College and the Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Bangkok 10330 (Thailand)

    2015-10-15

    Graphical abstract: - Highlights: • Activated carbon aerogel with high surface area can be prepared from polybenzoxazine. • Activated carbon aerogel enhances the adsorption capacity of gas sensor. • Organic vapors with very low concentration can be detected by the as-prepared sensor. • The as-prepared sensor shows impressive short exposure and recovery time. • The response to different organic vapors can be tailored by changing polymer matrix. - Abstract: Gas sensing composites were fabricated using polybenzoxazine-based activated carbon aerogel as a conductive filler. The activated carbon aerogel is a nano-porous material, which has high pore volume of 0.57 cm{sup 3}/g and surface area of 917 m{sup 2}/g. The activated carbon aerogel/polybutadiene composite displayed good response of 11.2 and 6.7 to toluene and n-hexane, respectively, compared to those of graphite/polybutadiene composite. The activated carbon aerogel/polybutadiene composite also showed high sensitivity of 3.09 × 10{sup 2} ppm{sup −1} to toluene. However, the sensitivity of activated carbon aerogel/polybutadiene composite drastically decreased to 1.99 ppm{sup −1} and zero when exposed to acetone and water, respectively. Contrarily, when polyvinyl alcohol was used as a matrix, the sensitivity was about 4.19 ppm{sup −1} to water. While the composite was found to be not sensitive to toluene. The activated carbon aerogel/polybutadiene composite also showed good recovery as the electrical resistance came back to the original value within minutes when exposed to nitrogen gas.

  18. Whole-body PET/MRI: The effect of bone attenuation during MR-based attenuation correction in oncology imaging

    DEFF Research Database (Denmark)

    Aznar, M.C.; Sersar, Rachida; Saabye, J.;

    2014-01-01

    .3%) and lowest for spongCT (–2.2%, range: 0.0% to –13.7%). Conclusions: In PET/MR imaging using standard MR-AC PET uptake values in soft lesions and bone lesions are underestimated by about 10%. In individual patients this bias can be as high as 22%, which is significant during clinical follow-up exams. If bone...... segmentation is available, then assigning a fixed attenuation value of spongious bone to all bone structures appears reasonable and results in only a minor bias of 5%, or less in uptake values of soft tissue and bone lesions.......Purpose: In combined PET/MRI standard PET attenuation correction (AC) is based on tissue segmentation following dedicated MR sequencing and, typically, bone tissue is not represented. We evaluate PET quantification in whole-body (WB)-PET/MRI following MR-AC without considering bone attenuation...

  19. Modelling and correction of the non-linear transverse dynamics of the LHC from beam-based measurements

    CERN Document Server

    Ewen, Hamish Maclean; Riccardo, Bartolini

    The non-linear beam dynamics of a circular accelerator, such as the Large Hadron Collider, can have a significant impact on its operation. In order to avoid limitations on the performance reach of the accelerator, and ensure machine protection, it is vital that the beam dynamics are well understood and controlled. This thesis presents the results of studies of non-linear beam dynamics undertaken on the Large Hadron Collider at CERN, during the 2010 to 2013 period. It sets out to quantify the understanding of the non-linear beam dynamics through the comparison of beam-based measurements to simulation, and where able and appropriate seeks to explain deviations of measurement from the model, and define corrections for relevant aspects of the dynamics. The analyses presented in this thesis represent considerable advances in the understanding of the LHC beam dynamics which should allow for an improved operation of the machine in the coming years.

  20. Maximum efficiency of ideal heat engines based on a small system: correction to the Carnot efficiency at the nanoscale.

    Science.gov (United States)

    Quan, H T

    2014-06-01

    We study the maximum efficiency of a heat engine based on a small system. It is revealed that due to the finiteness of the system, irreversibility may arise when the working substance contacts with a heat reservoir. As a result, there is a working-substance-dependent correction to the Carnot efficiency. We derive a general and simple expression for the maximum efficiency of a Carnot cycle heat engine in terms of the relative entropy. This maximum efficiency approaches the Carnot efficiency asymptotically when the size of the working substance increases to the thermodynamic limit. Our study extends Carnot's result of the maximum efficiency to an arbitrary working substance and elucidates the subtlety of thermodynamic laws in small systems.

  1. Nonrigid registration-based coronary artery motion correction for cardiac computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Bhagalia, Roshni; Pack, Jed D.; Miller, James V.; Iatrou, Maria [GE Global Research, Niskayuna, New York 12309 (United States); GE Healthcare, Hoboken, New Jersey 07030 (United States)

    2012-07-15

    Purpose: X-ray computed tomography angiography (CTA) is the modality of choice to noninvasively monitor and diagnose heart disease with coronary artery health and stenosis detection being of particular interest. Reliable, clinically relevant coronary artery imaging mandates high spatiotemporal resolution. However, advances in intrinsic scanner spatial resolution (CT scanners are available which combine nearly 900 detector columns with focal spot oversampling) can be tempered by motion blurring, particularly in patients with unstable heartbeats. As a result, recently numerous methods have been devised to improve coronary CTA imaging. Solutions involving hardware, multisector algorithms, or {beta}-blockers are limited by cost, oversimplifying assumptions about cardiac motion, and populations showing contraindications to drugs, respectively. This work introduces an inexpensive algorithmic solution that retrospectively improves the temporal resolution of coronary CTA without significantly affecting spatial resolution. Methods: Given the goal of ruling out coronary stenosis, the method focuses on 'deblurring' the coronary arteries. The approach makes no assumptions about cardiac motion, can be used on exams acquired at high heart rates (even over 75 beats/min), and draws on a fast and accurate three-dimensional (3D) nonrigid bidirectional labeled point matching approach to estimate the trajectories of the coronary arteries during image acquisition. Motion compensation is achieved by employing a 3D warping of a series of partial reconstructions based on the estimated motion fields. Each of these partial reconstructions is created from data acquired over a short time interval. For brevity, the algorithm 'Subphasic Warp and Add' (SWA) reconstruction. Results: The performance of the new motion estimation-compensation approach was evaluated by a systematic observer study conducted using nine human cardiac CTA exams acquired over a range of average heart

  2. Patient-specific scatter correction for flat-panel detector-based cone-beam CT imaging

    Science.gov (United States)

    Zhao, Wei; Brunner, Stephen; Niu, Kai; Schafer, Sebastian; Royalty, Kevin; Chen, Guang-Hong

    2015-02-01

    A patient-specific scatter correction algorithm is proposed to mitigate scatter artefacts in cone-beam CT (CBCT). The approach belongs to the category of convolution-based methods in which a scatter potential function is convolved with a convolution kernel to estimate the scatter profile. A key step in this method is to determine the free parameters introduced in both scatter potential and convolution kernel using a so-called calibration process, which is to seek for the optimal parameters such that the models for both scatter potential and convolution kernel is able to optimally fit the previously known coarse estimates of scatter profiles of the image object. Both direct measurements and Monte Carlo (MC) simulations have been proposed by other investigators to achieve the aforementioned rough estimates. In the present paper, a novel method has been proposed and validated to generate the needed coarse scatter profile for parameter calibration in the convolution method. The method is based upon an image segmentation of the scatter contaminated CBCT image volume, followed by a reprojection of the segmented image volume using a given x-ray spectrum. The reprojected data is subtracted from the scatter contaminated projection data to generate a coarse estimate of the needed scatter profile used in parameter calibration. The method was qualitatively and quantitatively evaluated using numerical simulations and experimental CBCT data acquired on a clinical CBCT imaging system. Results show that the proposed algorithm can significantly reduce scatter artefacts and recover the correct CT number. Numerical simulation results show the method is patient specific, can accurately estimate the scatter, and is robust with respect to segmentation procedure. For experimental and in vivo human data, the results show the CT number can be successfully recovered and anatomical structure visibility can be significantly improved.

  3. A Novel Error Correcting System Based on Product Codes for Future Magnetic Recording Channels

    CERN Document Server

    Van, Vo Tam

    2012-01-01

    We propose a novel construction of product codes for high-density magnetic recording based on binary low-density parity check (LDPC) codes and binary image of Reed Solomon (RS) codes. Moreover, two novel algorithms are proposed to decode the codes in the presence of both AWGN errors and scattered hard errors (SHEs). Simulation results show that at a bit error rate (bER) of approximately 10^-8, our method allows improving the error performance by approximately 1.9dB compared with that of a hard decision decoder of RS codes of the same length and code rate. For the mixed error channel including random noises and SHEs, the signal-to-noise ratio (SNR) is set at 5dB and 150 to 400 SHEs are randomly generated. The bit error performance of the proposed product code shows a significant improvement over that of equivalent random LDPC codes or serial concatenation of LDPC and RS codes.

  4. Correction and Densification of Uas-Based Photogrammetric Thermal Point Cloud

    Science.gov (United States)

    Akcay, O.; Erenoglu, R. C.; Erenoglu, O.

    2016-06-01

    Photogrammetric processing algorithms can suffer problems due to either the initial image quality (noise, low radiometric quality, shadows and so on) or to certain surface materials (shiny or textureless objects). This can result in noisy point clouds and/or difficulties in feature extraction. Specifically, dense point clouds which are generated with photogrammetric method using a lightweight thermal camera, are more noisy and sparse than the point clouds of high-resolution digital camera images. In this paper, new method which produces more reliable and dense thermal point cloud using the sparse thermal point cloud and high resolution digital point cloud was considered. Both thermal and digital images were obtained with UAS (Unmanned Aerial System) based lightweight Optris PI 450 and Canon EOS 605D camera images. Thermal and digital point clouds, and orthophotos were produced using photogrammetric methods. Problematic thermal point cloud was transformed to a high density thermal point cloud using image processing methods such as rasterizing, registering, interpolation and filling. The results showed that the obtained thermal point cloud - up to chosen processing parameters - was 87% more densify than the original point cloud. The second improvement was gained at the height accuracy of the thermal point cloud. New densified point cloud has more consistent elevation model while the original thermal point cloud shows serious deviations from the expected surface model.

  5. Room-temperature CW operation of a nitride-based vertical-cavity surface-emitting laser using thick GaInN quantum wells

    Science.gov (United States)

    Furuta, Takashi; Matsui, Kenjo; Horikawa, Kosuke; Ikeyama, Kazuki; Kozuka, Yugo; Yoshida, Shotaro; Akagi, Takanobu; Takeuchi, Tetsuya; Kamiyama, Satoshi; Iwaya, Motoaki; Akasaki, Isamu

    2016-05-01

    We demonstrated a room-temperature (RT) continuous-wave (CW) operation of a GaN-based vertical-cavity surface-emitting laser (VCSEL) using a thick GaInN quantum well (QW) active region and an AlInN/GaN distributed Bragg reflector. We first investigated the following two characteristics of a 6 nm GaInN 5 QWs active region in light-emitting diode (LED) structures. The light output power at a high current density (∼10 kA/cm2) from the 6 nm GaInN 5 QWs was the same or even higher than that from standard 3 nm 5 QWs. In addition, we found that hole injection into the farthest QW from a p-layer was sufficient. We then demonstrated a GaN-based VCSEL with the 6 nm 5 QWs, resulting in the optical confinement factor of 3.5%. The threshold current density under CW operation at RT was 7.5 kA/cm2 with a narrow (0.4 nm) emission spectrum of 413.5 nm peak wavelength.

  6. Vanadium Dioxide Nanoparticle-based Thermochromic Smart Coating: High Luminous Transmittance, Excellent Solar Regulation Efficiency, and Near Room Temperature Phase Transition.

    Science.gov (United States)

    Zhu, Jingting; Zhou, Yijie; Wang, Bingbing; Zheng, Jianyun; Ji, Shidong; Yao, Heliang; Luo, Hongjie; Jin, Ping

    2015-12-23

    An annealing-assisted preparation method of well-crystallized VxW1-xO2(M)@SiO2 core-shell nanoparticles for VO2-based thermochromic smart coatings (VTSC) is presented. The additional annealing process reduces the defect density of the initial hydrothermally prepared VxW1-xO2(M) nanoparticles and enhances their crystallinity so that the thermochromic film based on VxW1-xO2(M)@SiO2 nanoparticles can exhibit outstanding thermochromic performance with balanced solar regulation efficiency (ΔTsol) of 17.3%, luminous transmittance (Tlum) up to 52.2%, and critical phase transition temperature (Tc) around 40.4 °C, which is very promising for practical application. Furthermore, it makes great progress in reducing Tc of VTSC to near room temperature (25.2 °C) and simutaneously maintaining excellent optical properties (ΔTsol = 14.7% and Tlum = 50.6%). Such thermochromic performance is good enough to make VTSC applicable to practical architecture. PMID:26618391

  7. Selective Oxidation of Glycerol to Glyceric Acid in Base-Free Aqueous Solution at Room Temperature Catalyzed by Platinum Supported on Carbon Activated with Potassium Hydroxide

    KAUST Repository

    Tan, Hua

    2016-04-18

    Pt supported on KOH-activated mesoporous carbon (K-AMC) was used to catalyze glycerol oxidation under base-free conditions at room temperature. To study the relationship between the carbon surface chemistry and the catalytic performance of the K-AMC-based Pt catalysts, different levels of surface oxygen functional groups (SOFGs) on the AMC supports were induced by thermal treatment at different temperatures under inert or H2 gas. A strong effect of the surface chemistry was observed on AMC-supported Pt catalysts for glycerol oxidation. The presence of carboxylic acid groups impedes the adsorption of glycerol, which leads to the reduction of catalytic activity, whereas the presence of high-desorption-temperature SOFGs, such as phenol, ether, and carbonyl/quinone groups, provide hydrophilicity to the carbon surface that improves the adsorption of glycerol molecules on Pt metal surface, which is beneficial for the catalytic activity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Compact CH{sub 4} sensor system based on a continuous-wave, low power consumption, room temperature interband cascade laser

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Lei, E-mail: donglei@sxu.edu.cn [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006 (China); Li, Chunguang; Gluszek, Aleksander K.; Tittel, Frank K. [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Sanchez, Nancy P.; Griffin, Robert J. [Department of Civil and Environmental Engineering, Rice University, Houston, Texas 77005 (United States)

    2016-01-04

    A tunable diode laser absorption spectroscopy-based methane sensor, employing a dense-pattern multi-pass gas cell and a 3.3 μm, CW, DFB, room temperature interband cascade laser (ICL), is reported. The optical integration based on an advanced folded optical path design and an efficient ICL control system with appropriate electrical power management resulted in a CH{sub 4} sensor with a small footprint (32 × 20 × 17 cm{sup 3}) and low-power consumption (6 W). Polynomial and least-squares fit algorithms are employed to remove the baseline of the spectral scan and retrieve CH{sub 4} concentrations, respectively. An Allan-Werle deviation analysis shows that the measurement precision can reach 1.4 ppb for a 60 s averaging time. Continuous measurements covering a seven-day period were performed to demonstrate the stability and robustness of the reported CH{sub 4} sensor system.

  9. The pathogen- and incidence-based DALY approach: an appropriate [corrected] methodology for estimating the burden of infectious diseases.

    Directory of Open Access Journals (Sweden)

    Marie-Josée J Mangen

    Full Text Available In 2009, the European Centre for Disease Prevention and Control initiated the 'Burden of Communicable Diseases in Europe (BCoDE' project to generate evidence-based and comparable burden-of-disease estimates of infectious diseases in Europe. The burden-of-disease metric used was the Disability-Adjusted Life Year (DALY, composed of years of life lost due to premature death (YLL and due to disability (YLD. To better represent infectious diseases, a pathogen-based approach was used linking incident cases to sequelae through outcome trees. Health outcomes were included if an evidence-based causal relationship between infection and outcome was established. Life expectancy and disability weights were taken from the Global Burden of Disease Study and alternative studies. Disease progression parameters were based on literature. Country-specific incidence was based on surveillance data corrected for underestimation. Non-typhoidal Salmonella spp. and Campylobacter spp. were used for illustration. Using the incidence- and pathogen-based DALY approach the total burden for Salmonella spp. and Campylobacter spp. was estimated at 730 DALYs and at 1,780 DALYs per year in the Netherlands (average of 2005-2007. Sequelae accounted for 56% and 82% of the total burden of Salmonella spp. and Campylobacter spp., respectively. The incidence- and pathogen-based DALY methodology allows in the case of infectious diseases a more comprehensive calculation of the disease burden as subsequent sequelae are fully taken into account. Not considering subsequent sequelae would strongly underestimate the burden of infectious diseases. Estimates can be used to support prioritisation and comparison of infectious diseases and other health conditions, both within a country and between countries.

  10. Cardiac motion correction based on partial angle reconstructed images in x-ray CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seungeon; Chang, Yongjin; Ra, Jong Beom, E-mail: jbra@kaist.ac.kr [Department of Electrical Engineering, KAIST, Daejeon 305-701 (Korea, Republic of)

    2015-05-15

    two conjugate PAR images. To evaluate the proposed algorithm, digital XCAT and physical dynamic cardiac phantom datasets are used. The XCAT phantom datasets were generated with heart rates of 70 and 100 bpm, respectively, by assuming a system rotation time of 300 ms. A physical dynamic cardiac phantom was scanned using a slowly rotating XCT system so that the effective heart rate will be 70 bpm for a system rotation speed of 300 ms. Results: In the XCAT phantom experiment, motion-compensated 3D images obtained from the proposed algorithm show coronary arteries with fewer motion artifacts for all phases. Moreover, object boundaries contaminated by motion are well restored. Even though object positions and boundary shapes are still somewhat different from the ground truth in some cases, the authors see that visibilities of coronary arteries are improved noticeably and motion artifacts are reduced considerably. The physical phantom study also shows that the visual quality of motion-compensated images is greatly improved. Conclusions: The authors propose a novel PAR image-based cardiac motion estimation and compensation algorithm. The algorithm requires an angular scan range of less than 360°. The excellent performance of the proposed algorithm is illustrated by using digital XCAT and physical dynamic cardiac phantom datasets.

  11. Carotid wall volume quantification from magnetic resonance images using deformable model fitting and learning-based correction of systematic errors

    International Nuclear Information System (INIS)

    We present a method for carotid vessel wall volume quantification from magnetic resonance imaging (MRI). The method combines lumen and outer wall segmentation based on deformable model fitting with a learning-based segmentation correction step. After selecting two initialization points, the vessel wall volume in a region around the bifurcation is automatically determined. The method was trained on eight datasets (16 carotids) from a population-based study in the elderly for which one observer manually annotated both the lumen and outer wall. An evaluation was carried out on a separate set of 19 datasets (38 carotids) from the same study for which two observers made annotations. Wall volume and normalized wall index measurements resulting from the manual annotations were compared to the automatic measurements. Our experiments show that the automatic method performs comparably to the manual measurements. All image data and annotations used in this study together with the measurements are made available through the website http://ergocar.bigr.nl. (paper)

  12. Charge transport studies in donor-acceptor block copolymer PDPP-TNT and PC71BM based inverted organic photovoltaic devices processed in room conditions

    International Nuclear Information System (INIS)

    Diketopyrrolopyrole-naphthalene polymer (PDPP-TNT), a donor-acceptor co-polymer, has shown versatile behavior demonstrating high performances in organic field-effect transistors (OFETs) and organic photovoltaic (OPV) devices. In this paper we report investigation of charge carrier dynamics in PDPP-TNT, and [6,6]-phenyl C71 butyric acid methyl ester (PC71BM) bulk-heterojunction based inverted OPV devices using current density-voltage (J-V) characteristics, space charge limited current (SCLC) measurements, capacitance-voltage (C-V) characteristics, and impedance spectroscopy (IS). OPV devices in inverted architecture, ITO/ZnO/PDPP-TNT:PC71BM/MoO3/Ag, are processed and characterized at room conditions. The power conversion efficiency (PCE) of these devices are measured ∼3.8%, with reasonably good fill-factor 54.6%. The analysis of impedance spectra exhibits electron’s mobility ∼2 × 10−3 cm2V−1s−1, and lifetime in the range of 0.03-0.23 ms. SCLC measurements give hole mobility of 1.12 × 10−5 cm2V−1s−1, and electron mobility of 8.7 × 10−4 cm2V−1s−1

  13. Quantitative prediction of physical properties of imidazolium based room temperature ionic liquids through determination of condensed phase site charges: a refined force field.

    Science.gov (United States)

    Mondal, Anirban; Balasubramanian, Sundaram

    2014-03-27

    Quantitative prediction of physical properties of room temperature ionic liquids through nonpolarizable force field based molecular dynamics simulations is a challenging task. The challenge lies in the fact that mean ion charges in the condensed phase can be less than unity due to polarization and charge transfer effects whose magnitude cannot be fully captured through quantum chemical calculations conducted in the gas phase. The present work employed the density-derived electrostatic and chemical (DDEC/c3) charge partitioning method to calculate site charges of ions using electronic charge densities obtained from periodic density functional theory (DFT) calculations of their crystalline phases. The total ion charges obtained thus range between -0.6e for chloride and -0.8e for the PF6 ion. The mean value of the ion charges obtained from DFT calculations of an ionic liquid closely matches that obtained from the corresponding crystal thus confirming the suitability of using crystal site charges in simulations of liquids. These partial charges were deployed within the well-established force field developed by Lopes et al., and consequently, parameters of its nonbonded and torsional interactions were refined to ensure that they reproduced quantum potential energy scans for ion pairs in the gas phase. The refined force field was employed in simulations of seven ionic liquids with six different anions. Nearly quantitative agreement with experimental measurements was obtained for the density, surface tension, enthalpy of vaporization, and ion diffusion coefficients. PMID:24605817

  14. Optimised room temperature, water-based synthesis of CPO-27-M metal-organic frameworks with high space-time yields †

    Science.gov (United States)

    Garzón-Tovar, L.; Carné-Sánchez, A.; Carbonell, C.; Imaz, I.; Maspoch, D.

    2016-01-01

    The exceptional porosity of Metal-Organic Frameworks (MOFs) could be harnessed for countless practical applications. However, one of the challenges currently precluding the industrial exploitation of these materials is a lack of green methods for their synthesis. Since green synthetic methods obviate the use of organic solvents, they are expected to reduce the production costs, safety hazards and environmental impact typically associated with MOF fabrication. Herein we describe the stepwise optimisation of reaction parameters (pH, reagent concentrations and reaction time) for the room temperature, water-based synthesis of several members of the CPO-27/MOF-74-M series of MOFs, including ones made from Mg(II), Ni(II), Co(II) and Zn(II) ions. Using this method, we built MOFs with excellent BET surface areas and unprecedented Space-Time Yields (STYs). Employing this approach, we have synthesised CPO-27-M MOFs with record BET surface areas, including 1279 m2 g-1 (CPO-27-Zn), 1351 m2 g-1 (CPO-27-Ni), 1572 m2 g-1 (CPO-27-Co), and 1603 m2 g-1 (CPO-27-Mg). We anticipate that our method could be applied to produce CPO-27-Ni, -Mg, -Co and -Zn with STYs of 44 Kg m-3 day-1, 191 Kg m-3 day-1, 1462 Kg m-3 day-1 and a record 18720 Kg m-3 day-1, respectively. PMID:27293584

  15. Charge transport studies in donor-acceptor block copolymer PDPP-TNT and PC71BM based inverted organic photovoltaic devices processed in room conditions

    Science.gov (United States)

    Srivastava, Shashi B.; Sonar, Prashant; Singh, Samarendra P.

    2015-07-01

    Diketopyrrolopyrole-naphthalene polymer (PDPP-TNT), a donor-acceptor co-polymer, has shown versatile behavior demonstrating high performances in organic field-effect transistors (OFETs) and organic photovoltaic (OPV) devices. In this paper we report investigation of charge carrier dynamics in PDPP-TNT, and [6,6]-phenyl C71 butyric acid methyl ester (PC71BM) bulk-heterojunction based inverted OPV devices using current density-voltage (J-V) characteristics, space charge limited current (SCLC) measurements, capacitance-voltage (C-V) characteristics, and impedance spectroscopy (IS). OPV devices in inverted architecture, ITO/ZnO/PDPP-TNT:PC71BM/MoO3/Ag, are processed and characterized at room conditions. The power conversion efficiency (PCE) of these devices are measured ˜3.8%, with reasonably good fill-factor 54.6%. The analysis of impedance spectra exhibits electron's mobility ˜2 × 10-3 cm2V-1s-1, and lifetime in the range of 0.03-0.23 ms. SCLC measurements give hole mobility of 1.12 × 10-5 cm2V-1s-1, and electron mobility of 8.7 × 10-4 cm2V-1s-1.

  16. Charge transport studies in donor-acceptor block copolymer PDPP-TNT and PC71BM based inverted organic photovoltaic devices processed in room conditions

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Shashi B.; Singh, Samarendra P., E-mail: samarendra.singh@snu.edu.in [Department of Physics, Shiv Nadar University, Gautam Buddha Nagar, Uttar Pradesh, India-201307 (India); Sonar, Prashant [School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, Australia-4001 (Australia)

    2015-07-15

    Diketopyrrolopyrole-naphthalene polymer (PDPP-TNT), a donor-acceptor co-polymer, has shown versatile behavior demonstrating high performances in organic field-effect transistors (OFETs) and organic photovoltaic (OPV) devices. In this paper we report investigation of charge carrier dynamics in PDPP-TNT, and [6,6]-phenyl C{sub 71} butyric acid methyl ester (PC71BM) bulk-heterojunction based inverted OPV devices using current density-voltage (J-V) characteristics, space charge limited current (SCLC) measurements, capacitance-voltage (C-V) characteristics, and impedance spectroscopy (IS). OPV devices in inverted architecture, ITO/ZnO/PDPP-TNT:PC71BM/MoO{sub 3}/Ag, are processed and characterized at room conditions. The power conversion efficiency (PCE) of these devices are measured ∼3.8%, with reasonably good fill-factor 54.6%. The analysis of impedance spectra exhibits electron’s mobility ∼2 × 10{sup −3} cm{sup 2}V{sup −1}s{sup −1}, and lifetime in the range of 0.03-0.23 ms. SCLC measurements give hole mobility of 1.12 × 10{sup −5} cm{sup 2}V{sup −1}s{sup −1}, and electron mobility of 8.7 × 10{sup −4} cm{sup 2}V{sup −1}s{sup −1}.

  17. Development of a severe accident module of a nuclear power plant based in the MELCOR nuclear code and its incorporation to the room simulator

    International Nuclear Information System (INIS)

    This work describes the development of the Severe Accidents Module (MAS) based on the Code MELCOR and its incorporation to the Simulator of Classroom of the Group of Nuclear Engineering of the Engineering Faculty (GrINFI) of the National Autonomous University of Mexico (UNAM). The module of Severe Accidents has the purpose of counting with installed and operational capacity for the simulation of accident sequences with capacitation purposes, training, analysis and design. A shallow description of SimAula is presented, and the philosophy used to obtain the interactive version of MELCOR are discussed, as well as its implementation in the atmosphere of SimAula. Finally, after confirming the correct operation of the development of the tool, some possible topics are discussed for specific applications of the MAS. (Author)

  18. Design of splints based on the NiTi alloy for the correction of joint deformities in the fingers

    Directory of Open Access Journals (Sweden)

    Puértolas Sergio

    2010-09-01

    Full Text Available Abstract Background The proximal interphalange joint (PIP is fundamental for the functional nature of the hand. The contracture in flexion of the PIP, secondary to traumatisms or illnesses leads to an important functional loss. The use of correcting splints is the common procedure for treating this problem. Its functioning is based on the application of a small load and a prolonged stress which can be dynamic, static progressive or static serial. It is important that the therapist has a splint available which can release a constant and sufficient force to correct the contracture in flexion. Nowadays NiTi is commonly used in bio-engineering, due to its superelastical characteristics. The experience of the authors in the design of other devices based on the NiTi alloy, makes it possible to carry out a new design in this work - the production of a finger splint for the treatment of the contracture in flexion of the PIP joint. Methods Commercial orthosis have been characterized using a universal INSTRON 5565 machine. A computational simulation of the proposed design has been conducted, reproducing its performance and using a model "ad hoc" for the NiTi material. Once the parameters have been adjusted, the design is validated using the same type of test as those carried out on commercial orthosis. Results and Discussion For commercial splint the recovering force falls to excessively low values as the angle increases. Angle curves for different lengths and thicknesses of the proposed design have been obtained, with a practically constant recovering force value over a wide range of angles that vary between 30° and 150° in every case. Then the whole treatment is possible with only one splint, and without the need of progressive replacements as the joint recovers. Conclusions A new model of splint based on NiTi alloy has been designed, simulated and tested comparing its behaviour with two of the most regularly used splints. Its uses is recommended

  19. Accuracy and Radiation Dose of CT-Based Attenuation Correction for Small Animal PET: A Monte Carlo Simulation Study

    International Nuclear Information System (INIS)

    -Small animal PET allows qualitative assessment and quantitative measurement of biochemical processes in vivo, but the accuracy and reproducibility of imaging results can be affected by several parameters. The first aim of this study was to investigate the performance of different CT-based attenuation correction strategies and assess the resulting impact on PET images. The absorbed dose in different tissues caused by scanning procedures was also discussed to minimize biologic damage generated by radiation exposure due to PET/CT scanning. A small animal PET/CT system was modeled based on Monte Carlo simulation to generate imaging results and dose distribution. Three energy mapping methods, including the bilinear scaling method, the dual-energy method and the hybrid method which combines the kVp conversion and the dual-energy method, were investigated comparatively through assessing the accuracy of estimating linear attenuation coefficient at 511 keV and the bias introduced into PET quantification results due to CT-based attenuation correction. Our results showed that the hybrid method outperformed the bilinear scaling method, while the dual-energy method achieved the highest accuracy among the three energy mapping methods. Overall, the accuracy of PET quantification results have similar trend as that for the estimation of linear attenuation coefficients, whereas the differences between the three methods are more obvious in the estimation of linear attenuation coefficients than in the PET quantification results. With regards to radiation exposure from CT, the absorbed dose ranged between 7.29-45.58 mGy for 50-kVp scan and between 6.61-39.28 mGy for 80-kVp scan. For 18F radioactivity concentration of 1.86x105 Bq/ml, the PET absorbed dose was around 24 cGy for tumor with a target-to-background ratio of 8. The radiation levels for CT scans are not lethal to the animal, but concurrent use of PET in longitudinal study can increase the risk of biological effects. The

  20. A Geometrical-based Vertical Gain Correction for Signal Strength Prediction of Downtilted Base Station Antennas in Urban Areas

    DEFF Research Database (Denmark)

    Rodriguez, Ignacio; Nguyen, Huan Cong; Sørensen, Troels Bundgaard;

    2012-01-01

    Base station antenna downtilt is one of the most important parameters for optimizing a cellular network with tight frequency reuse. By downtilting, inter-site interference is reduced, which leads to an improved performance of the network. In this study we show that a simple geometrical...