Science.gov

Sample records for augmented nerve-mediated relaxation

  1. Activation of P2Y1 and P2Y2 nucleotide receptors by adenosine 5′-triphosphate analogues augmented nerve-mediated relaxation of human corpus cavernosum

    PubMed Central

    Gur, Serap; Hellstrom, Wayne J.G.

    2009-01-01

    Introduction Adenosine 5′-triphosphate (ATP) is a ubiquitous cellular energy source. We evaluated the effect of ATP and its analogues on nonadrenergic and noncholinergic relaxation in precontracted human corpus cavernosal smooth muscle (HCCSM). Methods We obtained specimens of human corpus cavernosum (HCC) from patients undergoing penile prosthesis surgery (patient age 46–70 yr, n = 17) with prior approval from the local institutional review board. Isolated HCC strips were placed in organ baths containing Krebs solution and functional experiments were conducted. Immunohistochemical localization studies were performed to establish the presence of purinergic P2X1, P2Y1 and P2Y2 receptors in HCC. Results The amplitude of relaxation induced by electrical-field stimulation (EFS) on HCC was significantly increased after exposure to ATP (P2X and P2Y agonists), 2-MeSATP (P2Y1 agonist), and uridine 5’ triphosphate (P2Y2 agonist), but not α,β-methylene ATP (P2X1 agonist). The P2X1 antagonist pyridoxal-5’-phosphate-6-azophenyl-2’, 4’-disulfonate, and the nonspecific P2Y antagonist, reactive blue 2, did not inhibit the potentiated response of EFS on HCC. Although immunoreactivity for both P2Y1 and P2Y2 receptors was localized abundantly in HCC, there was only low-level immunostaining for the P2X1 receptor. Conclusion These data demonstrate that nerve-mediated relaxation of HCCSM strips precontracted with phenylephrine in organ bath preparations is amplified by stimulating purinergic P2Y1 and P2Y2 receptors. Although nucleotides are important regulators of HCCSM tone, these observations suggest an independent purinergic relaxing mechanism in the HCC, separate from the better known nitrergic system. PMID:19672446

  2. Antagonist of nitric oxide synthesis inhibits nerve-mediated relaxation of isolated strips of rumen and reticulum.

    PubMed

    Schneider, D A; Eades, S C

    1998-10-01

    The present study investigated the possibility that nitric oxide is a nonadrenergic, noncholinergic neurotransmitter of nerves that are intrinsic to the forestomach. Tunica muscularis, myenteric plexus preparations of bovine reticulum and rumen were maintained in vitro in a physiological solution of buffer that contained scopolamine. Trains of electric field stimulation transiently reduced (relaxed) the tone induced by BaCl2. NG-Nitro-L-arginine methyl ester, a nitric oxide synthase competitive antagonist, inhibited relaxation of the rumen and reticulum preparations that had been induced by the electrical field. The actions of NG-nitro-L-arginine methyl ester were partially reversed by L-arginine. These data suggest that nitric oxide, or a related substance, is an inhibitory neurotransmitter of nerves that are intrinsic to tunica muscularis, myenteric plexus preparations of the bovine forestomach. PMID:9812264

  3. Relaxed core projector-augmented-wave method.

    PubMed

    Marsman, M; Kresse, G

    2006-09-14

    We extend the full-potential projector-augmented-wave method beyond the frozen core approximation, i.e., include the self-consistent optimization of the core charge density, in such a manner that the valence wave functions remain orthogonal to the core. The method consists of an on-the-fly repseudization of the all-electron problem, solving for the self-consistent core charge density within a spherical approximation. The key ideas in our procedure are to keep the projector functions fixed throughout the electronic minimization and to derive the new pseudopartial waves from these original projector functions, at each step of the electronic minimization procedure. Results of relaxed core calculations for atomic interconfigurational energies, structural energy differences between bulk phases of Fe, atomization energies of a subset of Pople's G2-1 set, and the Rh 3d surface core level shifts for the (log3 x log3)-Rh(111) surface at 1/3 CO coverage are presented. PMID:16999509

  4. Relaxed core projector-augmented-wave method

    NASA Astrophysics Data System (ADS)

    Marsman, M.; Kresse, G.

    2006-09-01

    We extend the full-potential projector-augmented-wave method beyond the frozen core approximation, i.e., include the self-consistent optimization of the core charge density, in such a manner that the valence wave functions remain orthogonal to the core. The method consists of an on-the-fly repseudization of the all-electron problem, solving for the self-consistent core charge density within a spherical approximation. The key ideas in our procedure are to keep the projector functions fixed throughout the electronic minimization and to derive the new pseudopartial waves from these original projector functions, at each step of the electronic minimization procedure. Results of relaxed core calculations for atomic interconfigurational energies, structural energy differences between bulk phases of Fe, atomization energies of a subset of Pople's G2-1 set, and the Rh 3d surface core level shifts for the (√3 ×√3 )-Rh(111) surface at 1/3 CO coverage are presented.

  5. Development of a low risk augmentation system for an energy efficient transport having relaxed static stability

    NASA Technical Reports Server (NTRS)

    Sizlo, T. R.; Berg, R. A.; Gilles, D. L.

    1979-01-01

    An augmentation system for a 230 passenger, twin engine aircraft designed with a relaxation of conventional longitudinal static stability was developed. The design criteria are established and candidate augmentation system control laws and hardware architectures are formulated and evaluated with respect to reliability, flying qualities, and flight path tracking performance. The selected systems are shown to satisfy the interpreted regulatory safety and reliability requirements while maintaining the present DC 10 (study baseline) level of maintainability and reliability for the total flight control system. The impact of certification of the relaxed static stability augmentation concept is also estimated with regard to affected federal regulations, system validation plan, and typical development/installation costs.

  6. Impaired parasympathetic augmentation under relaxation in patients with depression as assessed by a novel non-contact microwave radar system.

    PubMed

    Matsui, Takemi; Kakisaka, Kota; Shinba, Toshikazu

    2016-01-01

    In order to conduct objective screening of major depressive disorder (MDD), a chair-based system was developed which measures alteration of parasympathetic activation induced by relaxing audio-visual exposure in a non-contact way using dual compact-radars attached to a chair back. The system determines autonomic activation by calculating low (LF) and high frequency (HF) components of heart rate variability (HRV) before and after relaxation. Forty-one subjects (28 normal subjects, 13 MDD subjects) were exposed to relaxing natural sounds and images for 10 min. In order to determine the possibility of MDD from autonomic alteration induced by relaxing, linear discriminant analysis was conducted using LF and HF before and after relaxation. F-test revealed the significance of derived linear discriminant function (p < 0.001). The Mahalanobis distance and U value were 3.2 and 0.89, respectively. The derived linear discriminant function achieved 85% sensitivity (11 out of 13 MDD patients) and 89% specificity (25 out of 28 normal subjects). PMID:26728780

  7. Endothelin-1 increases cholinergic nerve-mediated contraction of human bronchi via tachykinin synthesis induction

    PubMed Central

    D'Agostino, Bruno; Advenier, Charles; Falciani, Maddalena; Gallelli, Luca; Marrocco, Giuseppina; Piegari, Elena; Filippelli, Amelia; Rossi, Francesco

    2001-01-01

    In some asthmatics, muscarinic receptor antagonists are effective in limiting bronchoconstrictor response, suggesting an abnormal cholinergic drive in these subjects. There is a growing body of evidences indicating that cholinergic neurotransmission is also enhanced by endothelin-1 (ET-1) in rabbit bronchi, mouse trachea and in human isolated airway preparations.We investigated the role of secondary mediators in ET-1 induced potentiation of cholinergic nerve-mediated contraction in human bronchi, in particular the possible role of neuropeptides in this phenomenon.Bronchial tissues after endothelin treatment were exposed to a standard electrical field stimulation (EFS) (30% of EFS 30Hz)-induced contraction. In addition, in some experiments, preparations were treated with a tachykinin NK2 receptor antagonist and subsequently exposed to the same protocol. HPLC and RIA were performed on organ bath fluid samples. Moreover, the human bronchi were used for the β-PPT (preprotachykinin) mRNA extraction and semiquantitative reverse transcription polymerase chain reaction (RT – PCR), prior to and 30 – 40 min following ET-1 challenge.The selective tachykinin NK2 receptor antagonist, SR48968, was effective to reduce ET-1 potentiation of EFS mediated contraction. HPLC or RIA showed significant increased quantities of NKA in organ bath effluents after EFS stimulation in bronchi pretreated with ET-1. Finally, β-PPT mRNA level after stimulation of bronchi with ET-1 was increased about 2 fold respect to control untreated bronchi.In conclusion, this study demonstrated that, at least in part, the ET-1 potentiation of cholinergic nerve-mediated contraction is mediated by tachykinin release, suggesting that in addition to nerves, several type of cells, such as airway smooth muscle cell, may participate to neuropeptide production. PMID:11724750

  8. Nerve-mediated antidiuresis and antinatriuresis after air-jet stress is modulated by angiotensin II.

    PubMed

    Veelken, R; Hilgers, K F; Stetter, A; Siebert, H G; Schmieder, R E; Mann, J F

    1996-11-01

    A putative interaction between angiotensin II (Ang II) and the sympathetic nervous system within the kidney has been reported. We tested the hypothesis in conscious rats that endogenous Ang II modulates the renal effects of a stress-induced increase in sympathetic nerve activity. We recorded mean arterial blood pressure, heart rate, renal sympathetic nerve activity, renal hemodynamics, urine volume, and urinary sodium content in conscious rats. We used the Ang II type 1 receptor blocker ZD 7155 to inhibit the effects of endogenous Ang II. Ten minutes of air-jet stress increased renal sympathetic nerve activity by 98 +/- 4% (n = 6) without changing systemic hemodynamics. Air-jet stress reduced urine volume (from 31 +/- 3 to 8 +/- 4 microL/min per gram kidney weight, P < .05, n = 12) and sodium excretion (from 4.3 +/- 0.9 to 1.2 +/- 0.3 mumol/min per gram kidney weight, P < .05, n = 12). After renal denervation, air-jet stress had no effect on either parameter. Six micrograms of the Ang II type 1 receptor inhibitor ZD 7155 blunted the decrease in urine volume and sodium excretion in response to air-jet stress, although the increase in renal sympathetic nerve activity during air-jet stress and the pressor response to exogenous Ang II were not affected. Glomerular filtration rate and renal plasma flow were also not affected. Higher doses of 30 and 60 micrograms ZD 7155 inhibited the pressor response to exogenous Ang II and abolished the changes in urine volume and sodium excretion in response to air-jet stress. None of the ZD 7155 doses affected urinary sodium excretion permanently. Hence, the Ang II type 1 receptor antagonist ZD 7155 impaired or abolished the renal nerve-mediated antinatriuresis and anitidiuresis in response to air-jet stress. We conclude that endogenous Ang II modulates the renal effects of centrally mediated changes of sympathetic nerve activity in conscious rats. PMID:8901830

  9. Influence of respiratory tract viral infection on endothelin-1-induced potentiation of cholinergic nerve-mediated contraction in mouse trachea.

    PubMed Central

    Carr, M. J.; Goldie, R. G.; Henry, P. J.

    1996-01-01

    from virus-inoculated mice was similar to that in tissue from control mice at days, 2, 4 and 8 post-inoculation. In contrast, sarafotoxin S6c (30 nM) did not enhance contractile responses of tracheal segments from control and virus-inoculated mice to exogenously applied acetylcholine (n = 3). 4. Endothelin-1 (1 nM) caused similar potentiations of standard EFS-induced contractions in tracheal segments from control (13 +/- 2% Cmax, n = 23) and virus-inoculated mice at day 2 (13 +/- 1% Cmax, n = 5), day 4 (16 +/- 5% Cmax, n = 6), and day 8 (13 +/- 3% Cmax, n = 8) post-inoculation. In contrast, 1 nM endothelin-1 did not enhance contractile responses of tracheal segments from control and virus-inoculated mice to exogenously applied acetylcholine (n = 4). Neither the ETA receptor-selective antagonist, BQ-123 (3 microM) nor the ETB receptor-selective antagonist, BQ-788 (1 microM) alone had any significant inhibitory effect on endothelin-1-induced potentiations of tracheal segments from control or virus-inoculated mice at days 2, 4 and 8 post-inoculation. However, simultaneous pre-incubation with BQ-123 (3 microM) and BQ-788 (1 microM) prevented endothelin-1-evoked potentiations, indicative of a role for both ETA and ETB receptors in this system. 5. These data clearly demonstrate that respiratory tract viral infection attenuated the function of the postjunctional ETB receptor-effector system linked directly to airway smooth muscle contraction. However, the function of prejunctional ETA and ETB receptor-effector systems linked to augmentation of cholinergic nerve-mediated airway smooth muscle contraction remained unaffected during respiratory tract viral infection in mice. PMID:8922737

  10. Lip augmentation.

    PubMed

    Byrne, Patrick J; Hilger, Peter A

    2004-02-01

    Lip augmentation has become increasingly popular in recent years as a reflection of cultural trends emphasizing youth and beauty. Techniques to enhance the appearance of the lips have evolved with advances in biotechnology. An understanding of lip anatomy and aesthetics forms the basis for successful results. We outline the pertinent anatomy and aesthetics of the preoperative evaluation. A summary of various filler materials available is provided. Augmentation options include both injectable and open surgical techniques. The procedures and materials currently favored by the authors are described in greater detail. PMID:15034811

  11. Chin augmentation.

    PubMed

    Choe, K S; Stucki-McCormick, S U

    2000-01-01

    The primary goal of facial aesthetic surgery is to restore, enhance, and rejuvenate the aging face to a more youthful appearance, achieving balance and harmony. The mental area must be addressed in order to have a complete synthesis of the face. The concept of augmenting the mental area with implants has evolved so significantly that it now stands by itself as an important procedure. Various autogenous implants for chin augmentation have been in use for over 100 years but have complications. The advent of synthetic materials has given rise to various types of alloplastic implants: Gore-Tex, Medpor, Supramid, Silastic, and Mersilene. No one implant is perfect for every face. This article overviews several alloplastic implants--their advantages, disadvantages, and complications, in addition to the different techniques of preparing and delivering the implants. PMID:11802346

  12. Relaxed Intensity

    ERIC Educational Resources Information Center

    Ramey, Kyle

    2004-01-01

    Relaxed intensity refers to a professional philosophy, demeanor, and way of life. It is the key to being an effective educational leader. To be successful one must be relaxed, which means managing stress efficiently, having fun, and enjoying work. Intensity allows one to get the job done and accomplish certain tasks or goals. Educational leaders…

  13. Augmented RIGS

    NASA Technical Reports Server (NTRS)

    Kaminskas, R. A.; Mcguire, D.

    1974-01-01

    The results of the Phase 2 Resonant Infrasonic Gauging System (RIGS) development program are presented. The program consisted of design, fabrication, and testing of an "augmented" RIGS concept. The RIGS is a gauging system capable of measuring propellant quantities in zero-g as well as under accelerated conditions. Except for hydrogen, it can be used to gauge virtually any propellant in liquid form, including cryogenics. The gage consists of a sensor unit which is attached to the propellant tank and an electronic control unit which may be positioned separately from the sensor. The control unit receives signals from the sensor as well as the propellant temperature measurement and the ullage gas pressure, and computes the propellant quantity in the tank.

  14. Relaxation System

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Environ Corporation's relaxation system is built around a body lounge, a kind of super easy chair that incorporates sensory devices. Computer controlled enclosure provides filtered ionized air to create a feeling of invigoration, enhanced by mood changing aromas. Occupant is also surrounded by multidimensional audio and the lighting is programmed to change colors, patterns, and intensity periodically. These and other sensory stimulators are designed to provide an environment in which the learning process is stimulated, because research has proven that while an individual is in a deep state of relaxation, the mind is more receptive to new information.

  15. Breast augmentation surgery

    MedlinePlus

    Breast augmentation; Breast implants; Implants - breast; Mammaplasty ... Breast augmentation is done by placing implants behind breast tissue or under the chest muscle. An implant is a sac filled with either sterile salt water (saline) or a ...

  16. Augmented Reality in astrophysics

    NASA Astrophysics Data System (ADS)

    Vogt, Frédéric P. A.; Shingles, Luke J.

    2013-09-01

    Augmented Reality consists of merging live images with virtual layers of information. The rapid growth in the popularity of smartphones and tablets over recent years has provided a large base of potential users of Augmented Reality technology, and virtual layers of information can now be attached to a wide variety of physical objects. In this article, we explore the potential of Augmented Reality for astrophysical research with two distinct experiments: (1) Augmented Posters and (2) Augmented Articles. We demonstrate that the emerging technology of Augmented Reality can already be used and implemented without expert knowledge using currently available apps. Our experiments highlight the potential of Augmented Reality to improve the communication of scientific results in the field of astrophysics. We also present feedback gathered from the Australian astrophysics community that reveals evidence of some interest in this technology by astronomers who experimented with Augmented Posters. In addition, we discuss possible future trends for Augmented Reality applications in astrophysics, and explore the current limitations associated with the technology. This Augmented Article, the first of its kind, is designed to allow the reader to directly experiment with this technology.

  17. Breathing and Relaxation

    MedlinePlus

    ... Top Doctors in the Nation Departments & Divisions Home Health Insights Stress & Relaxation Breathing and Relaxation Breathing and Relaxation Make ... Management Assess Your Stress Coping Strategies Identifying ... & Programs Health Insights Doctors & Departments Research & Science Education & Training Make ...

  18. Relaxation Assessment with Varied Structured Milieu (RELAX).

    ERIC Educational Resources Information Center

    Cassel, Russell N.; Cassel, Susie L.

    1983-01-01

    Describes Relaxation Assessment with Varied Structured Milieu (RELAX), a clinical program designed to assess the degree to which an individual is able to demonstrate self-control for overall general relaxation. The program is designed for use with the Cassel Biosensors biofeedback equipment. (JAC)

  19. Confronting an Augmented Reality

    ERIC Educational Resources Information Center

    Munnerley, Danny; Bacon, Matt; Wilson, Anna; Steele, James; Hedberg, John; Fitzgerald, Robert

    2012-01-01

    How can educators make use of augmented reality technologies and practices to enhance learning and why would we want to embrace such technologies anyway? How can an augmented reality help a learner confront, interpret and ultimately comprehend reality itself ? In this article, we seek to initiate a discussion that focuses on these questions, and…

  20. Equating of Augmented Subscores

    ERIC Educational Resources Information Center

    Sinharay, Sandip; Haberman, Shelby J.

    2011-01-01

    Recently, there has been an increasing level of interest in subscores for their potential diagnostic value. Haberman (2008b) suggested reporting an augmented subscore that is a linear combination of a subscore and the total score. Sinharay and Haberman (2008) and Sinharay (2010) showed that augmented subscores often lead to more accurate…

  1. Subfascial gluteal augmentation.

    PubMed

    de la Peña, J Abel; Rubio, Omar V; Cano, Jacobo P; Cedillo, Mariana C; Garcés, Miriam T

    2006-07-01

    Developing the concept of gluteal augmentation through the past 17 years has been an academic adventure. During these years my coworkers and I have progressively improved surgical technique and devised an anatomical system for gluteal augmentation that includes an ideal implant design and templates to assist in evaluating patients in the preoperative period and to identify the most appropriate implant size. PMID:16818097

  2. Augmented reality: a review.

    PubMed

    Berryman, Donna R

    2012-01-01

    Augmented reality is a technology that overlays digital information on objects or places in the real world for the purpose of enhancing the user experience. It is not virtual reality, that is, the technology that creates a totally digital or computer created environment. Augmented reality, with its ability to combine reality and digital information, is being studied and implemented in medicine, marketing, museums, fashion, and numerous other areas. This article presents an overview of augmented reality, discussing what it is, how it works, its current implementations, and its potential impact on libraries. PMID:22559183

  3. Breast augmentation surgery

    MedlinePlus

    ... the shape of your breasts. Talk with a plastic surgeon if you are considering breast augmentation. Discuss ... mammograms or breast x-rays before surgery. The plastic surgeon will do a routine breast exam. Several ...

  4. RMS active damping augmentation

    NASA Technical Reports Server (NTRS)

    Gilbert, Michael G.; Scott, Michael A.; Demeo, Martha E.

    1992-01-01

    The topics are presented in viewgraph form and include: RMS active damping augmentation; potential space station assembly benefits to CSI; LaRC/JSC bridge program; control law design process; draper RMS simulator; MIMO acceleration control laws improve damping; potential load reduction benefit; DRS modified to model distributed accelerations; accelerometer location; Space Shuttle aft cockpit simulator; simulated shuttle video displays; SES test goals and objectives; and SES modifications to support RMS active damping augmentation.

  5. Augmenting computer networks

    NASA Technical Reports Server (NTRS)

    Bokhari, S. H.; Raza, A. D.

    1984-01-01

    Three methods of augmenting computer networks by adding at most one link per processor are discussed: (1) A tree of N nodes may be augmented such that the resulting graph has diameter no greater than 4log sub 2((N+2)/3)-2. Thi O(N(3)) algorithm can be applied to any spanning tree of a connected graph to reduce the diameter of that graph to O(log N); (2) Given a binary tree T and a chain C of N nodes each, C may be augmented to produce C so that T is a subgraph of C. This algorithm is O(N) and may be used to produce augmented chains or rings that have diameter no greater than 2log sub 2((N+2)/3) and are planar; (3) Any rectangular two-dimensional 4 (8) nearest neighbor array of size N = 2(k) may be augmented so that it can emulate a single step shuffle-exchange network of size N/2 in 3(t) time steps.

  6. Ureteral bladder augmentation.

    PubMed

    Churchill, B M; Aliabadi, H; Landau, E H; McLorie, G A; Steckler, R E; McKenna, P H; Khoury, A E

    1993-08-01

    Virtually all segments of the gastrointestinal tract have been used successfully in augmentation cystoplasty. The complications inherent in enterocystoplasty are well described. Megaureters subtending effete kidneys (poorly or nonfunctioning) provide a novel and excellent source of augmentation material with urothelium and muscular backing, free of the electrolyte and acid base disturbances, and mucus production that plague enterocystoplasty. Augmentation cystoplasty using detubularized, reconfigured, otherwise disposable megaureter, with or without ipsilateral total or partial nephrectomy, was performed in 16 patients (mean age 8.8 years, range 1 to 25) with inadequate and dysfunctional bladders. Postoperative followup varied between 8 and 38 months (mean 22). The overall renal function and radiographic appearance of the remaining upper tracts have remained stable or improved in all patients. Of the 16 patients 15 require intermittent catheterization and 1 voids spontaneously. Ten patients are continent day and night, 5 have improved continence (4 damp at night and 1 stress incontinence) and 1 has failed to gain continence despite good capacity and compliance. Complete postoperative urodynamic evaluations in 12 of 13 patients show good capacity, low pressure bladders with no instability. Complications occurred in 5 patients, including transient urine extravasation in 2, contralateral ureterovesical obstruction in 2 and Mitrofanoff stomal stenosis in 1. Augmentation ureterocystoplasty combines the benefits common to all enterocystoplasties without adding any of the untoward complications or risks associated with nonurothelial augmentations. PMID:8326632

  7. Stress Relaxation in Entangled Melts of Unlinked Ring Polymers

    NASA Astrophysics Data System (ADS)

    Milner, Scott T.; Newhall, Jillian D.

    2010-11-01

    Stress relaxation in unlinked ring polymer melts poses an important challenge to our theoretical understanding of entangled polymer dynamics. Recent experiments on entangled unlinked ring melts show power-law stress relaxation with no hint of a rubbery plateau, usually the hallmark of entangled polymers. Here we present a theory for stress relaxation in rings analogous to the successful approach for star polymers. We augment our theory with mesoscale Monte Carlo dynamics simulations of equivalent “lattice animal” configurations. We find a stress relaxation function G(t)˜t-α with α≈1/2 consistent with experiment, emerging ultimately from the disparate relaxation times of more- and less-central portions of ring conformations.

  8. Augmented Thermal Bus

    NASA Technical Reports Server (NTRS)

    Schrage, Dean S. (Inventor)

    1996-01-01

    The present invention is directed to an augmented thermal bus. In the present design a plurality of thermo-electric heat pumps are used to couple a source plate to a sink plate. Each heat pump is individually controlled by a model based controller. The controller coordinates the heat pumps to maintain isothermality in the source.

  9. Augmented thermal bus

    NASA Technical Reports Server (NTRS)

    Schrage, Dean S. (Inventor)

    1993-01-01

    The present invention is directed to an augmented thermal bus. In the present design a plurity of thermo-electric heat pumps are used to couple a source plate to a sink plate. Each heat pump is individually controlled by a model based controller. The controller coordinates the heat pump to maintain isothermality in the source.

  10. Computer Augmented Lectures

    ERIC Educational Resources Information Center

    Seitz, W. A.; Matsen, F. A.

    1974-01-01

    Discusses the use of a central computer linked to a CRT console, with display projected onto a large screen, to operate computer augmentation of lectures in large group instruction. Indicates that both introductory tutorial and computer modes are feasible in subject matter presentation. (CC)

  11. Augmentative & Alternative Communication

    ERIC Educational Resources Information Center

    Murphy, Patti

    2007-01-01

    There is no definitive recipe for augmentative and alternative communication (AAC) success, but its universal ingredients can be found at home. The main ones are: (1) Understanding that all children need to express themselves, however outgoing or shy they may be; (2) Willingness to embrace the technology that may help your child regardless of your…

  12. Augmented Reality Binoculars.

    PubMed

    Oskiper, Taragay; Sizintsev, Mikhail; Branzoi, Vlad; Samarasekera, Supun; Kumar, Rakesh

    2015-05-01

    In this paper we present an augmented reality binocular system to allow long range high precision augmentation of live telescopic imagery with aerial and terrain based synthetic objects, vehicles, people and effects. The inserted objects must appear stable in the display and must not jitter and drift as the user pans around and examines the scene with the binoculars. The design of the system is based on using two different cameras with wide field of view and narrow field of view lenses enclosed in a binocular shaped shell. Using the wide field of view gives us context and enables us to recover the 3D location and orientation of the binoculars much more robustly, whereas the narrow field of view is used for the actual augmentation as well as to increase precision in tracking. We present our navigation algorithm that uses the two cameras in combination with an inertial measurement unit and global positioning system in an extended Kalman filter and provides jitter free, robust and real-time pose estimation for precise augmentation. We have demonstrated successful use of our system as part of information sharing example as well as a live simulated training system for observer training, in which fixed and rotary wing aircrafts, ground vehicles, and weapon effects are combined with real world scenes. PMID:26357208

  13. Batten augmented triangular beam

    NASA Technical Reports Server (NTRS)

    Adams, Louis R.; Hedgepeth, John M.

    1986-01-01

    The BAT (Batten-Augmented Triangular) BEAM is characterized by battens which are buckled in the deployed state, thus preloading the truss. The preload distribution is determined, and the effects of various external loading conditions are investigated. The conceptual design of a deployer is described and loads are predicted. The influence of joint imperfections on effective member stiffness is investigated. The beam is assessed structurally.

  14. Postreduction Breast Augmentation

    PubMed Central

    Doft, Melissa A.

    2015-01-01

    Background: Most breast reduction patients are highly satisfied after surgery. However, there is a subset of women who seek breast augmentation years later to restore lost volume chiefly associated with weight loss and postpartum changes. Breast shape and overall aesthetics are often revised at the same time. Methods: A retrospective review was performed of 2 surgeons’ experiences with post-reduction breast augmentation. Twenty patients were identified between 2002 and 2014. An in-depth chart review was conducted to determine patient motivation and to examine the operative techniques employed. Implant variables, a reduction specimen weight to implant volume comparison (where available), and complications are reported. Results: The average age was 37.1 years and average body mass index was 21.8 kg/m2. Most patients waited over a decade to have their breasts revised. Weight loss was the motivating factor in 8 patients and pregnancy changes in 11. Nineteen patients wished to stay with the same bra size or 1 cup size larger. Although all patients elected to have an implant placed, 19 patients wished to have an improved breast shape, not specifically a larger volume. The average breast implant was 203.5 cm3 (range, 120–340 cm3). Complications from implant placement included a seroma treated by aspiration and a Baker class III capsular contracture that required surgical correction. Conclusions: A small subset of reduction mammaplasty patients seek breast augmentation many years later primarily to improve breast contour, not to restore their prereduction breast volumes. Conservative augmentation combined with revision of breast shape and areolar aesthetics yields good results with minimal complications. PMID:26579333

  15. Mechanism of rotational relaxation.

    NASA Technical Reports Server (NTRS)

    Polanyi, J. C.; Woodall, K. B.

    1972-01-01

    A model is presented which describes the characteristic pattern of relaxation of a nonthermal rotational distribution of hydrogen halide, peaked initially at high rotational quantum number J, to a thermal distribution without generating a peak at intermediate J. A method for correcting infrared chemiluminiscence data for modest rotational relaxation is also suggested.

  16. TEACHING NEUROMUSCULAR RELAXATION.

    ERIC Educational Resources Information Center

    NORRIS, JEANNE E.; STEINHAUS, ARTHUR H.

    THIS STUDY ATTEMPTED TO FIND OUT WHETHER (1) THE METHODS FOR ATTAINING NEUROMUSCULAR RELAXATION THAT HAVE PROVED FRUITFUL IN THE ONE-TO-ONE RELATIONSHIP OF THE CLINIC CAN BE SUCCESSFULLY ADAPTED TO THE TEACHER-CLASS RELATIONSHIP OF THE CLASSROOM AND GYMNASIUM, AND (2) NEUROMUSCULAR RELAXATION CAN BE TAUGHT SUCCESSFULLY BY AN APPROPRIATELY TRAINED…

  17. Development and flight evaluation of an augmented stability active controls concept with a small tail

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Parasite drag reduction evaluation is composed of wind tunnel tests with a standard L-1011 tail and two reduced area tail configurations. Trim drag reduction is evaluated by rebalancing the airplane for relaxed static stability. This is accomplished by pumping water to tanks in the forward and aft of the airplane to acheive desired center of gravity location. Also, the L-1011 is modified to incorporate term and advanced augmented systems. By using advanced wings and aircraft relaxed static stability significant fuel savings can be realized. An airplane's dynamic stability becomes more sensitive for decreased tail size, relaxed static stability, and advanced wing configurations. Active control pitch augmentation will be used to acheive the required handling qualities. Flight tests will be performed to evaluate the pitch augmentation systems. The effect of elevator downrig on stabilizer/elevator hinge moments will be measured. For control system analysis, the normal acceleration feedback and pitch rate feedback are analyzed.

  18. Neurally augmented sexual function.

    PubMed

    Meloy, S

    2007-01-01

    Neurally Augmented Sexual Function (NASF) is a technique utilizing epidural electrodes to restore and improve sexual function. Orgasmic dysfunction is common in adult women, affecting roughly one quarter of populations studied. Many male patients suffering from erectile dysfunction are not candidates for phosphdiesterase therapy due to concomitant nitrate therapy. Positioning the electrodes at roughly the level of the cauda equina allows for stimulation of somatic efferents and afferents as well as modifying sympathetic and parasympathetic activity. Our series of women treated by NASF is described. Our experience shows that the evaluation of potential candidates for both correctable causes and psychological screening are important considerations. PMID:17691397

  19. History of gluteal augmentation.

    PubMed

    de la Peña, J Abel; Rubio, Omar V; Cano, Jacobo P; Cedillo, Mariana C; Garcés, Miriam T

    2006-07-01

    The concept of female beauty has changed throughout time, but the form and size of the breasts and gluteal region have remained constant as symbols of maximum femininity. Sculptures and prints show us feminine figures that are voluminous and reflect human history's interest in fertility. The early years of gluteal augmentation saw few published reports that described the procedure technique, follow-up, or possible complications. But developments continued as surgeons began experimenting with different anatomical planes for implant placement. The most important goal in plastic surgery is meeting a patient's expectations. It is important for the surgeon to thoroughly explain to patients what can realistically be achieved with a procedure. PMID:16818090

  20. Mutually Augmented Cognition

    NASA Astrophysics Data System (ADS)

    Friesdorf, Florian; Pangercic, Dejan; Bubb, Heiner; Beetz, Michael

    In mac, an ergonomic dialog-system and algorithms will be developed that enable human experts and companions to be integrated into knowledge gathering and decision making processes of highly complex cognitive systems (e.g. Assistive Household as manifested further in the paper). In this event we propose to join algorithms and methodologies coming from Ergonomics and Artificial Intelligence that: a) make cognitive systems more congenial for non-expert humans, b) facilitate their comprehension by utilizing a high-level expandable control code for human experts and c) augment representation of such cognitive system into “deep representation” obtained through an interaction with human companions.

  1. Analysis of Aeroheating Augmentation due to Reaction Control System Jets on Orion Crew Exploration Vehicle

    NASA Technical Reports Server (NTRS)

    Dyakonov, Artem A.; Buck, Gregory M.; Decaro, Anthony D.

    2009-01-01

    The analysis of effects of the reaction control system jet plumes on aftbody heating of Orion entry capsule is presented. The analysis covered hypersonic continuum part of the entry trajectory. Aerothermal environments at flight conditions were evaluated using Langley Aerothermal Upwind Relaxation Algorithm (LAURA) code and Data Parallel Line Relaxation (DPLR) algorithm code. Results show a marked augmentation of aftbody heating due to roll, yaw and aft pitch thrusters. No significant augmentation is expected due to forward pitch thrusters. Of the conditions surveyed the maximum heat rate on the aftshell is expected when firing a pair of roll thrusters at a maximum deceleration condition.

  2. Pilot-optimal augmentation synthesis

    NASA Technical Reports Server (NTRS)

    Schmidt, D. K.

    1978-01-01

    An augmentation synthesis method usable in the absence of quantitative handling qualities specifications, and yet explicitly including design objectives based on pilot-rating concepts, is presented. The algorithm involves the unique approach of simultaneously solving for the stability augmentation system (SAS) gains, pilot equalization and pilot rating prediction via optimal control techniques. Simultaneous solution is required in this case since the pilot model (gains, etc.) depends upon the augmented plant dynamics, and the augmentation is obviously not a priori known. Another special feature is the use of the pilot's objective function (from which the pilot model evolves) to design the SAS.

  3. A quantum relaxation-time approximation for finite fermion systems

    SciTech Connect

    Reinhard, P.-G.; Suraud, E.

    2015-03-15

    We propose a relaxation time approximation for the description of the dynamics of strongly excited fermion systems. Our approach is based on time-dependent density functional theory at the level of the local density approximation. This mean-field picture is augmented by collisional correlations handled in relaxation time approximation which is inspired from the corresponding semi-classical picture. The method involves the estimate of microscopic relaxation rates/times which is presently taken from the well established semi-classical experience. The relaxation time approximation implies evaluation of the instantaneous equilibrium state towards which the dynamical state is progressively driven at the pace of the microscopic relaxation time. As test case, we consider Na clusters of various sizes excited either by a swift ion projectile or by a short and intense laser pulse, driven in various dynamical regimes ranging from linear to strongly non-linear reactions. We observe a strong effect of dissipation on sensitive observables such as net ionization and angular distributions of emitted electrons. The effect is especially large for moderate excitations where typical relaxation/dissipation time scales efficiently compete with ionization for dissipating the available excitation energy. Technical details on the actual procedure to implement a working recipe of such a quantum relaxation approximation are given in appendices for completeness.

  4. Augmented Virtual Reality Laboratory

    NASA Technical Reports Server (NTRS)

    Tully-Hanson, Benjamin

    2015-01-01

    Real time motion tracking hardware has for the most part been cost prohibitive for research to regularly take place until recently. With the release of the Microsoft Kinect in November 2010, researchers now have access to a device that for a few hundred dollars is capable of providing redgreenblue (RGB), depth, and skeleton data. It is also capable of tracking multiple people in real time. For its original intended purposes, i.e. gaming, being used with the Xbox 360 and eventually Xbox One, it performs quite well. However, researchers soon found that although the sensor is versatile, it has limitations in real world applications. I was brought aboard this summer by William Little in the Augmented Virtual Reality (AVR) Lab at Kennedy Space Center to find solutions to these limitations.

  5. NASA Communications Augmentation network

    NASA Technical Reports Server (NTRS)

    Omidyar, Guy C.; Butler, Thomas E.; Laios, Straton C.

    1990-01-01

    The NASA Communications (Nascom) Division of the Mission Operations and Data Systems Directorate (MO&DSD) is to undertake a major initiative to develop the Nascom Augmentation (NAUG) network to achieve its long-range service objectives for operational data transport to support the Space Station Freedom Program, the Earth Observing System (EOS), and other projects. The NAUG is the Nascom ground communications network being developed to accommodate the operational traffic of the mid-1990s and beyond. The NAUG network development will be based on the Open Systems Interconnection Reference Model (OSI-RM). This paper describes the NAUG network architecture, subsystems, topology, and services; addresses issues of internetworking the Nascom network with other elements of the Space Station Information System (SSIS); discusses the operations environment. This paper also notes the areas of related research and presents the current conception of how the network will provide broadband services in 1998.

  6. NASA Communications Augmentation network

    NASA Astrophysics Data System (ADS)

    Omidyar, Guy C.; Butler, Thomas E.; Laios, Straton C.

    1990-09-01

    The NASA Communications (Nascom) Division of the Mission Operations and Data Systems Directorate (MO&DSD) is to undertake a major initiative to develop the Nascom Augmentation (NAUG) network to achieve its long-range service objectives for operational data transport to support the Space Station Freedom Program, the Earth Observing System (EOS), and other projects. The NAUG is the Nascom ground communications network being developed to accommodate the operational traffic of the mid-1990s and beyond. The NAUG network development will be based on the Open Systems Interconnection Reference Model (OSI-RM). This paper describes the NAUG network architecture, subsystems, topology, and services; addresses issues of internetworking the Nascom network with other elements of the Space Station Information System (SSIS); discusses the operations environment. This paper also notes the areas of related research and presents the current conception of how the network will provide broadband services in 1998.

  7. Magnetohydrodynamic Augmented Propulsion Experiment

    NASA Technical Reports Server (NTRS)

    Litchford, Ron J.

    2008-01-01

    Over the past several years, efforts have been under way to design and develop an operationally flexible research facility for investigating the use of cross-field MHD accelerators as a potential thrust augmentation device for thermal propulsion systems. The baseline configuration for this high-power experimental facility utilizes a 1.5-MWe multi-gas arc-heater as a thermal driver for a 2-MWe MHD accelerator, which resides in a large-bore 2-tesla electromagnet. A preliminary design study using NaK seeded nitrogen as the working fluid led to an externally diagonalized segmented MHD channel configuration based on an expendable heat-sink design concept. The current status report includes a review of engineering/design work and performance optimization analyses and summarizes component hardware fabrication and development efforts, preliminary testing results, and recent progress toward full-up assembly and testing

  8. Augmented reality system

    NASA Astrophysics Data System (ADS)

    Lin, Chien-Liang; Su, Yu-Zheng; Hung, Min-Wei; Huang, Kuo-Cheng

    2010-08-01

    In recent years, Augmented Reality (AR)[1][2][3] is very popular in universities and research organizations. The AR technology has been widely used in Virtual Reality (VR) fields, such as sophisticated weapons, flight vehicle development, data model visualization, virtual training, entertainment and arts. AR has characteristics to enhance the display output as a real environment with specific user interactive functions or specific object recognitions. It can be use in medical treatment, anatomy training, precision instrument casting, warplane guidance, engineering and distance robot control. AR has a lot of vantages than VR. This system developed combines sensors, software and imaging algorithms to make users feel real, actual and existing. Imaging algorithms include gray level method, image binarization method, and white balance method in order to make accurate image recognition and overcome the effects of light.

  9. NAESA Augmentation Pilot Project

    NASA Technical Reports Server (NTRS)

    Hoover, John J.

    1998-01-01

    This project was one project within the Native American Earth and Space Academy (NAESA). NAESA is a national initiative comprised of several organizations that support programs which focus on 1) enhancing the technological, scientific and pedagogical skills of K-14 teachers who instruct Native Americans, 2) enhancing the understanding and applications of science, technology, and engineering of college-bound Native Americans and teaching them general college "survival skills" (e.g., test taking, time management, study habits), 3) enhancing the scientific and pedagogical skills of the faculty of tribally-controllcd colleges and community colleges with large Native American enrollments, and 4) strengthening the critical relationships between students, their parents, tribal elders, and their communities. This Augmentation Pilot Project focused on the areas of community-school alliances and intemet technology use in teaching and learning and daily living addressing five major objectives.

  10. Augmented Reality Comes to Physics

    ERIC Educational Resources Information Center

    Buesing, Mark; Cook, Michael

    2013-01-01

    Augmented reality (AR) is a technology used on computing devices where processor-generated graphics are rendered over real objects to enhance the sensory experience in real time. In other words, what you are really seeing is augmented by the computer. Many AR games already exist for systems such as Kinect and Nintendo 3DS and mobile apps, such as…

  11. Dielectric relaxation time spectroscopy.

    PubMed

    Paulson, K S; Jouravleva, S; McLeod, C N

    2000-11-01

    A new mathematical method is developed to recover the permittivity relaxation spectrum of living tissue from measurements of the real and imaginary parts of the impedance. Aiming to derive information about electrical properties of living tissue without the prior selection of any impedance model, the procedure calculates the relaxation time distribution. It provides new characteristic independent parameters: time constants, their distribution, and the amplitudes of the associated dispersion. As the beta-dispersion is the most important in the area of electrical impedance spectroscopy of tissue, the paper gives an estimate of the essential frequency range to cover the whole relaxation spectrum in that area. Results are presented from both simulation and known lumped--constant element circuit. PMID:11077745

  12. Magnetohydrodynamic Augmented Propulsion Experiment

    NASA Technical Reports Server (NTRS)

    Litchford, Ron J.; Cole, John; Lineberry, John; Chapman, Jim; Schmidt, Harold; Cook, Stephen (Technical Monitor)

    2002-01-01

    A fundamental obstacle to routine space access is the specific energy limitations associated with chemical fuels. In the case of vertical take-off, the high thrust needed for vertical liftoff and acceleration to orbit translates into power levels in the 10 GW range. Furthermore, useful payload mass fractions are possible only if the exhaust particle energy (i.e., exhaust velocity) is much greater than that available with traditional chemical propulsion. The electronic binding energy released by the best chemical reactions (e.g., LOX/LH2 for example, is less than 2 eV per product molecule (approx. 1.8 eV per H2O molecule), which translates into particle velocities less than 5 km/s. Useful payload fractions, however, will require exhaust velocities exceeding 15 km/s (i.e., particle energies greater than 20 eV). As an added challenge, the envisioned hypothetical RLV (reusable launch vehicle) should accomplish these amazing performance feats while providing relatively low acceleration levels to orbit (2-3g maximum). From such fundamental considerations, it is painfully obvious that planned and current RLV solutions based on chemical fuels alone represent only a temporary solution and can only result in minor gains, at best. What is truly needed is a revolutionary approach that will dramatically reduce the amount of fuel and size of the launch vehicle. This implies the need for new compact high-power energy sources as well as advanced accelerator technologies for increasing engine exhaust velocity. Electromagnetic acceleration techniques are of immense interest since they can be used to circumvent the thermal limits associated with conventional propulsion systems. This paper describes the Magnetohydrodynamic Augmented Propulsion Experiment (MAPX) being undertaken at NASA Marshall Space Flight Center (MSFC). In this experiment, a 1-MW arc heater is being used as a feeder for a 1-MW magnetohydrodynamic (MHD) accelerator. The purpose of the experiment is to demonstrate

  13. Augmented Likelihood Image Reconstruction.

    PubMed

    Stille, Maik; Kleine, Matthias; Hägele, Julian; Barkhausen, Jörg; Buzug, Thorsten M

    2016-01-01

    The presence of high-density objects remains an open problem in medical CT imaging. Data of projections passing through objects of high density, such as metal implants, are dominated by noise and are highly affected by beam hardening and scatter. Reconstructed images become less diagnostically conclusive because of pronounced artifacts that manifest as dark and bright streaks. A new reconstruction algorithm is proposed with the aim to reduce these artifacts by incorporating information about shape and known attenuation coefficients of a metal implant. Image reconstruction is considered as a variational optimization problem. The afore-mentioned prior knowledge is introduced in terms of equality constraints. An augmented Lagrangian approach is adapted in order to minimize the associated log-likelihood function for transmission CT. During iterations, temporally appearing artifacts are reduced with a bilateral filter and new projection values are calculated, which are used later on for the reconstruction. A detailed evaluation in cooperation with radiologists is performed on software and hardware phantoms, as well as on clinically relevant patient data of subjects with various metal implants. Results show that the proposed reconstruction algorithm is able to outperform contemporary metal artifact reduction methods such as normalized metal artifact reduction. PMID:26208310

  14. Control Augmented Structural Synthesis

    NASA Technical Reports Server (NTRS)

    Lust, Robert V.; Schmit, Lucien A.

    1988-01-01

    A methodology for control augmented structural synthesis is proposed for a class of structures which can be modeled as an assemblage of frame and/or truss elements. It is assumed that both the plant (structure) and the active control system dynamics can be adequately represented with a linear model. The structural sizing variables, active control system feedback gains and nonstructural lumped masses are treated simultaneously as independent design variables. Design constraints are imposed on static and dynamic displacements, static stresses, actuator forces and natural frequencies to ensure acceptable system behavior. Multiple static and dynamic loading conditions are considered. Side constraints imposed on the design variables protect against the generation of unrealizable designs. While the proposed approach is fundamentally more general, here the methodology is developed and demonstrated for the case where: (1) the dynamic loading is harmonic and thus the steady state response is of primary interest; (2) direct output feedback is used for the control system model; and (3) the actuators and sensors are collocated.

  15. Perceptually Augmented Simulator Design.

    PubMed

    Edmunds, T; Pai, D K

    2012-01-01

    Training simulators have proven their worth in a variety of fields, from piloting to air-traffic control to nuclear power station monitoring. Designing surgical simulators, however, poses the challenge of creating trainers that effectively instill not only high-level understanding of the steps to be taken in a given situation, but also the low-level "muscle-memory" needed to perform delicate surgical procedures. It is often impossible to build an ideal simulator that perfectly mimics the haptic experience of a surgical procedure, but by focussing on the aspects of the experience that are perceptually salient we can build simulators that effectively instill learning. We propose a general method for the design of surgical simulators that augment the perceptually salient aspects of an interaction. Using this method, we can increase skill-transfer rates without requiring expensive improvements in the capability of the rendering hardware or the computational complexity of the simulation. In this paper, we present our decomposition-based method for surgical simulator design, and describe a user-study comparing the training effectiveness of a haptic-search-task simulator designed using our method versus an unaugmented simulator. The results show that perception-based task decomposition can be used to improve the design of surgical simulators that effectively impart skill by targeting perceptually significant aspects of the interaction. PMID:26963831

  16. Structural consequences of railgun augmentation

    SciTech Connect

    Wellman, G.W.; Schuler, K.W. . Applied Mechanics Div. III)

    1989-01-01

    An augmented railgun can provide the same driving force on a projectile at a lower plasma arc current and thus less potential erosion and barrel damage as an unaugmented railgun. However, there are structural consequences to railgun augmentation which must be overcome before the advantages of lower plasma arc currents can be realized. To investigate these consequences, a bolted V-block supporting structure is considered with two cores; unaugmented (a single pair of conducting rails), and augmented (conducting rails augmented by a second tandem set of conductors). The mechanical load on the cores consist of the static bolt preload, the plasma pressure behind the projectile, and the magnetic pressure induced by currents flowing in the rails or augmenting conductors. Assuming no current diffusion into the conductors, the magnetic pressure distribution on the conductors is determined by solving the two dimensional magnetostatic field equations using an analogy with heat transfer. These loads are then used in a dynamic finite element structural model. The maximum rail current is found at which the unaugmented railgun can be repetitively fired without detrimental gaps forming at the bore. For the augmented railgun, at the same projectile acceleration, large permanent deformations can occur. Thus successful implementation of rail gun augmentation will require improvement of the supporting structure.

  17. Structural consequences of railgun augmentation

    SciTech Connect

    Wellman, G.W.; Schuler, K.W.

    1988-01-01

    An augmented railgun can provide the same driving force on a projectile at a lower plasma arc current and thus less potential erosion and barrel damage as an unaugmented railgun. However, there are structural consequences to railgun augmentation which must be overcome before the advantages of lower plasma arc currents can be realized. To investigate these consequences, a bolted V-block supporting structure is considered with two cores; unaugmented (a single pair of conducting rails), and augmented (conducting rails augmented by a second tandem set of conductors). The mechanical load on the cores consist of the static bolt preload, the plasma pressure behind the projectile, and the magnetic pressure induced by currents flowing in the rails or augmenting conductors. Assuming no current diffusion into the conductors, the magnetic pressure distribution on the conductors is determined by solving the two-dimensional magnetostatic field equations using an analogy with heat transfer. These loads are then used in a dynamic finite element structural model. The maximum rail current is found at which the unaugmented railgun can be repetitively fired without detrimental gaps forming at the bore. For the augmented railgun, at the same projectile acceleration, large permanent deformations can occur. Thus successful implementation of rail gun augmentation will require improvement of the supporting structure.

  18. RELAX: detecting relaxed selection in a phylogenetic framework.

    PubMed

    Wertheim, Joel O; Murrell, Ben; Smith, Martin D; Kosakovsky Pond, Sergei L; Scheffler, Konrad

    2015-03-01

    Relaxation of selective strength, manifested as a reduction in the efficiency or intensity of natural selection, can drive evolutionary innovation and presage lineage extinction or loss of function. Mechanisms through which selection can be relaxed range from the removal of an existing selective constraint to a reduction in effective population size. Standard methods for estimating the strength and extent of purifying or positive selection from molecular sequence data are not suitable for detecting relaxed selection, because they lack power and can mistake an increase in the intensity of positive selection for relaxation of both purifying and positive selection. Here, we present a general hypothesis testing framework (RELAX) for detecting relaxed selection in a codon-based phylogenetic framework. Given two subsets of branches in a phylogeny, RELAX can determine whether selective strength was relaxed or intensified in one of these subsets relative to the other. We establish the validity of our test via simulations and show that it can distinguish between increased positive selection and a relaxation of selective strength. We also demonstrate the power of RELAX in a variety of biological scenarios where relaxation of selection has been hypothesized or demonstrated previously. We find that obligate and facultative γ-proteobacteria endosymbionts of insects are under relaxed selection compared with their free-living relatives and obligate endosymbionts are under relaxed selection compared with facultative endosymbionts. Selective strength is also relaxed in asexual Daphnia pulex lineages, compared with sexual lineages. Endogenous, nonfunctional, bornavirus-like elements are found to be under relaxed selection compared with exogenous Borna viruses. Finally, selection on the short-wavelength sensitive, SWS1, opsin genes in echolocating and nonecholocating bats is relaxed only in lineages in which this gene underwent pseudogenization; however, selection on the functional

  19. Relaxation techniques for stress

    MedlinePlus

    ... Know. February 2013. Available at: nccih.nih.gov/health/stress/relaxation.htm . Accessed September 21, 2015. National Center ... A.D.A.M. Editorial team. Related MedlinePlus Health Topics Stress Browse the Encyclopedia A.D.A.M., Inc. ...

  20. Augmented Reality Comes to Physics

    NASA Astrophysics Data System (ADS)

    Buesing, Mark; Cook, Michael

    2013-04-01

    Augmented reality (AR) is a technology used on computing devices where processor-generated graphics are rendered over real objects to enhance the sensory experience in real time. In other words, what you are really seeing is augmented by the computer. Many AR games already exist for systems such as Kinect and Nintendo 3DS and mobile apps, such as Tagwhat and Star Chart (a must for astronomy class). The yellow line marking first downs in a televised football game2 and the enhanced puck that makes televised hockey easier to follow3 both use augmented reality to do the job.

  1. Relaxation of Actinide Surfaces: An All Electron Study

    NASA Astrophysics Data System (ADS)

    Atta-Fynn, Raymond; Dholabhai, Pratik; Ray, Asok

    2006-10-01

    Fully relativistic full potential density functional calculations with a linearized augmented plane wave plus local orbitals basis (LAPW + lo) have been performed to investigate the relaxations of heavy actinide surfaces, namely the (111) surface of fcc δ-Pu and the (0001) surface of dhcp Am using WIEN2k. This code uses the LAPW + lo method with the unit cell divided into non-overlapping atom-centered spheres and an interstitial region. The APW+lo basis is used to describe all s, p, d, and f states and LAPW basis to describe all higher angular momentum states. Each surface was modeled by a three-layer periodic slab separated by 60 Bohr vacuum with four atoms per surface unit cell. In general, we have found a contraction of the interlayer separations for both Pu and Am. We will report, in detail, the electronic and geometric structures of the relaxed surfaces and comparisons with the respective non-relaxed surfaces.

  2. Mersiline mesh in premaxillary augmentation.

    PubMed

    Foda, Hossam M T

    2005-01-01

    Premaxillary retrusion may distort the aesthetic appearance of the columella, lip, and nasal tip. This defect is characteristically seen in, but not limited to, patients with cleft lip nasal deformity. This study investigated 60 patients presenting with premaxillary deficiencies in which Mersiline mesh was used to augment the premaxilla. All the cases had surgery using the external rhinoplasty technique. Two methods of augmentation with Mersiline mesh were used: the Mersiline roll technique, for the cases with central symmetric deficiencies, and the Mersiline packing technique, for the cases with asymmetric deficiencies. Premaxillary augmentation with Mersiline mesh proved to be simple technically, easy to perform, and not associated with any complications. Periodic follow-up evaluation for a mean period of 32 months (range, 12-98 months) showed that an adequate degree of premaxillary augmentation was maintained with no clinically detectable resorption of the mesh implant. PMID:15959688

  3. Effective Augmentation of Complex Networks.

    PubMed

    Wang, Jinjian; Yu, Xinghuo; Stone, Lewi

    2016-01-01

    Networks science plays an enormous role in many aspects of modern society from distributing electrical power across nations to spreading information and social networking amongst global populations. While modern networks constantly change in size, few studies have sought methods for the difficult task of optimising this growth. Here we study theoretical requirements for augmenting networks by adding source or sink nodes, without requiring additional driver-nodes to accommodate the change i.e., conserving structural controllability. Our "effective augmentation" algorithm takes advantage of clusters intrinsic to the network topology, and permits rapidly and efficient augmentation of a large number of nodes in one time-step. "Effective augmentation" is shown to work successfully on a wide range of model and real networks. The method has numerous applications (e.g. study of biological, social, power and technological networks) and potentially of significant practical and economic value. PMID:27165120

  4. Scale and Rotation Invariant Matching Using Linearly Augmented Trees.

    PubMed

    Jiang, Hao; Tian, Tai-Peng; Sclaroff, Stan

    2015-12-01

    We propose a novel linearly augmented tree method for efficient scale and rotation invariant object matching. The proposed method enforces pairwise matching consistency defined on trees, and high-order constraints on all the sites of a template. The pairwise constraints admit arbitrary metrics while the high-order constraints use L1 norms and therefore can be linearized. Such a linearly augmented tree formulation introduces hyperedges and loops into the basic tree structure. But, different from a general loopy graph, its special structure allows us to relax and decompose the optimization into a sequence of tree matching problems that are efficiently solvable by dynamic programming. The proposed method also works on continuous scale and rotation parameters; we can match with a scale up to any large value with the same efficiency. Our experiments on ground truth data and a variety of real images and videos show that the proposed method is efficient, accurate and reliable. PMID:26539858

  5. Hair Dye and Hair Relaxers

    MedlinePlus

    ... For Consumers Consumer Information by Audience For Women Hair Dye and Hair Relaxers Share Tweet Linkedin Pin it More sharing ... products. If you have a bad reaction to hair dyes and relaxers, you should: Stop using the ...

  6. Dielectric Relaxation of Hexadeutero Dimethylsulfoxide

    NASA Astrophysics Data System (ADS)

    Betting, H.; Stockhausen, M.

    1999-11-01

    The dielectric relaxation parameters of the title substance (DMSO-d6) in its pure liquid state are determined from meas-urements up to 72 GHz at 20°C in comparison to protonated DMSO. While the relaxation strengths do not differ, the relax-ation time of DMSO-d 6 is significantly longer (21.3 ps) than that of DMSO (19.5 ps).

  7. Relaxation in Physical Education Curricula.

    ERIC Educational Resources Information Center

    Coville, Claudia A.

    1979-01-01

    A theoretical framework for incorporating relaxation instruction in the physical education curriculum is presented based on the assumption that relaxation is a muscular-skeletal skill benefitting general motor skill acquisition. Theoretical principles, a definition of relaxation, and an analysis of stages of skill development are also used in the…

  8. Relaxation phenomena in disordered systems

    NASA Astrophysics Data System (ADS)

    Sciortino, F.; Tartaglia, P.

    1997-02-01

    In this article we discuss how the assumptions of self-similarity imposed on the distribution of independently relaxing modes, as well as on their amplitude and characteristic times, manifest in the global relaxation phenomena. We also review recent applications of such approach to the description of relaxation phenomena in microemulsions and molecular glasses.

  9. A Comparison of Relaxation Strategies.

    ERIC Educational Resources Information Center

    Matthews, Doris B.

    Some researchers argue that all relaxation techniques produce a single relaxation response while others support a specific-effects hypothesis which suggests that progressive relaxation affects the musculoskeletal system and that guided imagery affects cognitive changes. Autogenics is considered a technique which is both somatic and cognitive. This…

  10. Augmented Reality Tower Technology Assessment

    NASA Technical Reports Server (NTRS)

    Reisman, Ronald J.; Brown, David M.

    2009-01-01

    Augmented Reality technology may help improve Air Traffic Control Tower efficiency and safety during low-visibility conditions. This paper presents the assessments of five off-duty controllers who shadow-controlled' with an augmented reality prototype in their own facility. Initial studies indicated unanimous agreement that this technology is potentially beneficial, though the prototype used in the study was not adequate for operational use. Some controllers agreed that augmented reality technology improved situational awareness, had potential to benefit clearance, control, and coordination tasks and duties and could be very useful for acquiring aircraft and weather information, particularly aircraft location, heading, and identification. The strongest objections to the prototype used in this study were directed at aircraft registration errors, unacceptable optical transparency, insufficient display performance in sunlight, inadequate representation of the static environment and insufficient symbology.

  11. Augmentation cystoplasty in neurogenic bladder.

    PubMed

    Çetinel, Bülent; Kocjancic, Ervin; Demirdağ, Çetin

    2016-09-01

    The aim of this review is to update the indications, contraindications, technique, complications, and the tissue engineering approaches of augmentation cystoplasty (AC) in patients with neurogenic bladder. PubMed/MEDLINE was searched for the keywords "augmentation cystoplasty," "neurogenic bladder," and "bladder augmentation." Additional relevant literature was determined by examining the reference lists of articles identified through the search. The update review of of the indications, contraindications, technique, outcome, complications, and tissue engineering approaches of AC in patients with neurogenic bladder is presented. Although some important progress has been made in tissue engineering AC, conventional AC still has an important role in the surgical treatment of refractory neurogenic lower urinary tract dysfunction. PMID:27617312

  12. Augmentation mentoplasty using Mersilene mesh.

    PubMed

    McCollough, E G; Hom, D B; Weigel, M T; Anderson, J R

    1990-10-01

    Many different materials are available for augmentation mentoplasty. However, the optimal implant material for chin implantation has yet to be found. During the past several years, a number of experienced surgeons have turned to the use of Mersilene mesh. Mersilene mesh is a non-absorbable Dacron polyester fiber that can be conformed easily into layers to achieve tailored dimensions and shape. At the McCollough Plastic Surgery Clinic PA, Birmingham, Ala, 277 patients over a 10-year period underwent chin augmentation with Mersilene mesh implants. The material provides excellent tensile strength, durability, and surgical adaptability. The overall complication rate was 3.2% (nine patients); infection rate, 2.5% (seven patients); and removal secondary to infection, 1.7% (five patients). Based on this 10-year experience, Mersilene mesh remains our material of choice for chin augmentation. PMID:2206500

  13. Augmentation cystoplasty in neurogenic bladder

    PubMed Central

    Kocjancic, Ervin; Demirdağ, Çetin

    2016-01-01

    The aim of this review is to update the indications, contraindications, technique, complications, and the tissue engineering approaches of augmentation cystoplasty (AC) in patients with neurogenic bladder. PubMed/MEDLINE was searched for the keywords "augmentation cystoplasty," "neurogenic bladder," and "bladder augmentation." Additional relevant literature was determined by examining the reference lists of articles identified through the search. The update review of of the indications, contraindications, technique, outcome, complications, and tissue engineering approaches of AC in patients with neurogenic bladder is presented. Although some important progress has been made in tissue engineering AC, conventional AC still has an important role in the surgical treatment of refractory neurogenic lower urinary tract dysfunction. PMID:27617312

  14. Augmentation-related brain plasticity.

    PubMed

    Di Pino, Giovanni; Maravita, Angelo; Zollo, Loredana; Guglielmelli, Eugenio; Di Lazzaro, Vincenzo

    2014-01-01

    Today, the anthropomorphism of the tools and the development of neural interfaces require reconsidering the concept of human-tools interaction in the framework of human augmentation. This review analyses the plastic process that the brain undergoes when it comes into contact with augmenting artificial sensors and effectors and, on the other hand, the changes that the use of external augmenting devices produces in the brain. Hitherto, few studies investigated the neural correlates of augmentation, but clues on it can be borrowed from logically-related paradigms: sensorimotor training, cognitive enhancement, cross-modal plasticity, sensorimotor functional substitution, use and embodiment of tools. Augmentation modifies function and structure of a number of areas, i.e., primary sensory cortices shape their receptive fields to become sensitive to novel inputs. Motor areas adapt the neuroprosthesis representation firing-rate to refine kinematics. As for normal motor outputs, the learning process recruits motor and premotor cortices and the acquisition of proficiency decreases attentional recruitment, focuses the activity on sensorimotor areas and increases the basal ganglia drive on the cortex. Augmentation deeply relies on the frontoparietal network. In particular, premotor cortex is involved in learning the control of an external effector and owns the tool motor representation, while the intraparietal sulcus extracts its visual features. In these areas, multisensory integration neurons enlarge their receptive fields to embody supernumerary limbs. For operating an anthropomorphic neuroprosthesis, the mirror system is required to understand the meaning of the action, the cerebellum for the formation of its internal model and the insula for its interoception. In conclusion, anthropomorphic sensorized devices can provide the critical sensory afferences to evolve the exploitation of tools through their embodiment, reshaping the body representation and the sense of the self

  15. Augmentation-related brain plasticity

    PubMed Central

    Di Pino, Giovanni; Maravita, Angelo; Zollo, Loredana; Guglielmelli, Eugenio; Di Lazzaro, Vincenzo

    2014-01-01

    Today, the anthropomorphism of the tools and the development of neural interfaces require reconsidering the concept of human-tools interaction in the framework of human augmentation. This review analyses the plastic process that the brain undergoes when it comes into contact with augmenting artificial sensors and effectors and, on the other hand, the changes that the use of external augmenting devices produces in the brain. Hitherto, few studies investigated the neural correlates of augmentation, but clues on it can be borrowed from logically-related paradigms: sensorimotor training, cognitive enhancement, cross-modal plasticity, sensorimotor functional substitution, use and embodiment of tools. Augmentation modifies function and structure of a number of areas, i.e., primary sensory cortices shape their receptive fields to become sensitive to novel inputs. Motor areas adapt the neuroprosthesis representation firing-rate to refine kinematics. As for normal motor outputs, the learning process recruits motor and premotor cortices and the acquisition of proficiency decreases attentional recruitment, focuses the activity on sensorimotor areas and increases the basal ganglia drive on the cortex. Augmentation deeply relies on the frontoparietal network. In particular, premotor cortex is involved in learning the control of an external effector and owns the tool motor representation, while the intraparietal sulcus extracts its visual features. In these areas, multisensory integration neurons enlarge their receptive fields to embody supernumerary limbs. For operating an anthropomorphic neuroprosthesis, the mirror system is required to understand the meaning of the action, the cerebellum for the formation of its internal model and the insula for its interoception. In conclusion, anthropomorphic sensorized devices can provide the critical sensory afferences to evolve the exploitation of tools through their embodiment, reshaping the body representation and the sense of the self

  16. Gluteal augmentation with cryopreserved fat.

    PubMed

    Moscatiello, Fabrizio; Aznar-Benitah, Salvador; Grella, Roberto; Jover, Javier Herrero

    2010-03-01

    Gluteal augmentation with autologous fat is becoming a standard ancillary procedure for sculpting the buttock area. The high rate of resorption due to aggressive harvesting techniques or inadequate injection procedures often leads to repeated treatments. Currently, several techniques for storing fat by controlled freezing and thawing procedures can guarantee a high rate of cell viability, similar to that obtained with fresh tissue. This allows surgeons to compile fat tissue available for future repeat injections, decreasing additional costs and morbidity for patients. The authors describe a case of gluteal augmentation with cryopreserved fat in a 42-year-old man. PMID:20442098

  17. Relaxing music for anxiety control.

    PubMed

    Elliott, Dave; Polman, Remco; McGregor, Richard

    2011-01-01

    The purpose of this investigation was to determine the characteristics of relaxing music for anxiety control. Undergraduate students (N=84) were instructed to imagine themselves in an anxiety producing situation while listening to a selection of 30 music compositions. For each composition, level of relaxation, the factors that either enhanced or detracted from its relaxing potential and the emotional labels attached were assessed. Participants were also asked to state which music components (e.g., tempo, melody) were most conducive to relaxation. Additional information was obtained through the use of a focus group of 6 undergraduate music students. This paper presents details on the characteristics of relaxing-music for anxiety control and emotional labels attached to the relaxing compositions. Furthermore, an importance value has been attached to each of the music components under scrutiny, thus providing an indication of which music components should receive greatest attention when selecting music for anxiety control. PMID:22097099

  18. Computer Augmented Learning; A Survey.

    ERIC Educational Resources Information Center

    Kindred, J.

    The report contains a description and summary of computer augmented learning devices and systems. The devices are of two general types programed instruction systems based on the teaching machines pioneered by Pressey and developed by Skinner, and the so-called "docile" systems that permit greater user-direction with the computer under student…

  19. Augmenting a Classical Electrochemical Demonstration.

    ERIC Educational Resources Information Center

    Yochum, Susan M.; Luoma, John R.

    1995-01-01

    Presents an augmentation of a classical electrochemical demonstration that addresses the learning styles of the students and teaches electrochemistry in a concrete manner. Enables each student to see each event clearly, repeatedly, or in stop-action mode and enables students to improve their own mental models by providing them with a visually…

  20. Gluteus augmentation with fat grafting.

    PubMed

    Perén, P A; Gómez, J B; Guerrerosantos, J; Salazar, C A

    2000-01-01

    This study presents the authors' experience with gluteus augmentation with autologus fat grafts and liposuction methods, having recorded the evolution of gluteus reshaping with autologus intramuscular fat graft injections for the past 5 years. Preoperative shape is discussed and patient evaluations, operative techniques, postoperative management, and longterm results are emphasized. PMID:11246428

  1. Renormalized reaction and relaxation rates

    NASA Astrophysics Data System (ADS)

    Gorbachev, Yuriy E.

    2016-06-01

    Impact of the non-equilibrium on the reaction and relaxation rates (called as generalized relaxation rates - GRR), for the spatially inhomogeneous gas mixture is considered. Discarding the assumption that the 'chemical' part of the collisional integral is a small correction to non-reactive part, the expression for the zero-order GRR is derived. They are represented as a renormalization of the traditional reaction and relaxation rates, which means mixing of all corresponding processes. Thus all reactions and relaxation processes are entangled.

  2. Comet Bursting Through Relaxation

    NASA Astrophysics Data System (ADS)

    Jacobson, Seth A.; Scheeres, D. J.

    2012-10-01

    Comets may be excited and occupy non-principal axis (complex) rotation states for a large fraction of their lifetimes. Many comet nuclei have been identified or are suspected to occupy non-principal axis (complex) rotation [Belton 2005, etc.] as well as have evolving rotation rates [Belton 2011, etc.]. Comet orbits drive these rotation states through cycles of excitation due to surface jets and relaxation due to time variable internal stresses that dissipate energy in the anelastic comet interior. Furthermore, relaxation from complex rotation can increase the loads along the symmetry axis of prolate comets. These loads stretch the body along the symmetry axis and may be the cause of the characteristic ``bowling pin’’ shape and eventually may lead to failure. This is an alternative model for comet bursting. Each cycle deposits only a small amount of energy and stress along the axis, but this process is repeated every orbit during which jets are activated. Our model for the evolution of comet nuclei includes torques due to a number of discrete jets located on the surface based on Neishtadt et al. [2002]. The model also includes internal dissipation using an approach developed by Sharma et al. [2005] and Vokrouhlicky et al. [2009]. These equations are averaged over the instantaneous spin state and the heliocentric orbit so the long-term evolution of the comet can be determined. We determine that even after the inclusion of internal dissipation there still exist non-principal axis equilibrium states for certain jet geometries. For ranges of dissipation factors and jet geometries, prolate comets are found to occupy states that have time variable internal loads over long time periods. These periodic loadings along the symmetry axis may lead to ``necking’’ as the body extends along the axis to release the stress and eventually disruption.

  3. Measuring the Longitudinal NMR Relaxation Rates of Fast Relaxing Nuclei Using a Signal Eliminating Relaxation Filter

    NASA Astrophysics Data System (ADS)

    Hansen, D. Flemming; Led, Jens J.

    2001-08-01

    A new experiment for selective determination of the relaxation rates of fast relaxing NMR signals is presented. The experiment is derived from the conventional inversion recovery experiment by substituting the 180° inversion pulse of this experiment with a signal eliminating relaxation filter (SERF) consisting of three 180° pulses separated by two variable delays, Δ1 and Δ2. The SERF experiment allows a selective suppression of signals with relaxation rates below a given limit while monitoring the relaxation of faster relaxing signals. The experiment was tested on a sample of 20% oxidized plastocyanin from Anabaena variabilis, where the fast exchange of an electron between the reduced (diamagnetic) and the oxidized (paramagnetic) form results in a series of average signals with widely different relaxation rates. To ensure an optimum extraction of information from the experimental data, the relaxation rates were obtained from the SERF experiment by a simultaneous analysis of all the FIDs of the experiment using a fast linear prediction model method developed previously. The reliability of the relaxation rates obtained from the SERF experiment was confirmed by a comparison of the rates with the corresponding rates obtained from a conventional inversion recovery experiment.

  4. Augmented reality building operations tool

    DOEpatents

    Brackney, Larry J.

    2014-09-09

    A method (700) for providing an augmented reality operations tool to a mobile client (642) positioned in a building (604). The method (700) includes, with a server (660), receiving (720) from the client (642) an augmented reality request for building system equipment (612) managed by an energy management system (EMS) (620). The method (700) includes transmitting (740) a data request for the equipment (612) to the EMS (620) and receiving (750) building management data (634) for the equipment (612). The method (700) includes generating (760) an overlay (656) with an object created based on the building management data (634), which may be sensor data, diagnostic procedures, or the like. The overlay (656) is configured for concurrent display on a display screen (652) of the client (642) with a real-time image of the building equipment (612). The method (700) includes transmitting (770) the overlay (656) to the client (642).

  5. Effective Augmentation of Complex Networks

    NASA Astrophysics Data System (ADS)

    Wang, Jinjian; Yu, Xinghuo; Stone, Lewi

    2016-05-01

    Networks science plays an enormous role in many aspects of modern society from distributing electrical power across nations to spreading information and social networking amongst global populations. While modern networks constantly change in size, few studies have sought methods for the difficult task of optimising this growth. Here we study theoretical requirements for augmenting networks by adding source or sink nodes, without requiring additional driver-nodes to accommodate the change i.e., conserving structural controllability. Our “effective augmentation” algorithm takes advantage of clusters intrinsic to the network topology, and permits rapidly and efficient augmentation of a large number of nodes in one time-step. “Effective augmentation” is shown to work successfully on a wide range of model and real networks. The method has numerous applications (e.g. study of biological, social, power and technological networks) and potentially of significant practical and economic value.

  6. Effective Augmentation of Complex Networks

    PubMed Central

    Wang, Jinjian; Yu, Xinghuo; Stone, Lewi

    2016-01-01

    Networks science plays an enormous role in many aspects of modern society from distributing electrical power across nations to spreading information and social networking amongst global populations. While modern networks constantly change in size, few studies have sought methods for the difficult task of optimising this growth. Here we study theoretical requirements for augmenting networks by adding source or sink nodes, without requiring additional driver-nodes to accommodate the change i.e., conserving structural controllability. Our “effective augmentation” algorithm takes advantage of clusters intrinsic to the network topology, and permits rapidly and efficient augmentation of a large number of nodes in one time-step. “Effective augmentation” is shown to work successfully on a wide range of model and real networks. The method has numerous applications (e.g. study of biological, social, power and technological networks) and potentially of significant practical and economic value. PMID:27165120

  7. Media-Augmented Exercise Machines

    NASA Astrophysics Data System (ADS)

    Krueger, T.

    2002-01-01

    Cardio-vascular exercise has been used to mitigate the muscle and cardiac atrophy associated with adaptation to micro-gravity environments. Several hours per day may be required. In confined spaces and long duration missions this kind of exercise is inevitably repetitive and rapidly becomes uninteresting. At the same time, there are pressures to accomplish as much as possible given the cost- per-hour for humans occupying orbiting or interplanetary. Media augmentation provides a the means to overlap activities in time by supplementing the exercise with social, recreational, training or collaborative activities and thereby reducing time pressures. In addition, the machine functions as an interface to a wide range of digital environments allowing for spatial variety in an otherwise confined environment. We hypothesize that the adoption of media augmented exercise machines will have a positive effect on psycho-social well-being on long duration missions. By organizing and supplementing exercise machines, data acquisition hardware, computers and displays into an interacting system this proposal increases functionality with limited additional mass. This paper reviews preliminary work on a project to augment exercise equipment in a manner that addresses these issues and at the same time opens possibilities for additional benefits. A testbed augmented exercise machine uses a specialty built cycle trainer as both input to a virtual environment and as an output device from it using spatialized sound, and visual displays, vibration transducers and variable resistance. The resulting interactivity increases a sense of engagement in the exercise, provides a rich experience of the digital environments. Activities in the virtual environment and accompanying physiological and psychological indicators may be correlated to track and evaluate the health of the crew.

  8. TDRSS Augmentation System for Satellites

    NASA Technical Reports Server (NTRS)

    Heckler, Gregory W.; Gramling, Cheryl; Valdez, Jennifer; Baldwin, Philip

    2016-01-01

    In 2015, NASA Goddard Space Flight Center (GSFC) reinvigorated the development of the TDRSS Augmentation Service for Satellites (TASS). TASS is a global, space-based, communications and navigation service for users of Global Navigation Satellite Systems(GNSS) and the Tracking and Data Relay Satellite System (TDRSS). TASS leverages the existing TDRSS to provide an S-band beacon radio navigation and messaging source to users at orbital altitudes 1400 km and below.

  9. Aesthetic occiput augmentation using methylmethacrylate.

    PubMed

    Song, Yong Tai

    2015-01-01

    Cranioplasty for only aesthetic reasons has not been commonly performed to date. However, recently there has been a new focus by the public on a more aesthetically pleasing head shape with frequent patient requests for purely aesthetic contouring of the occiput, an important definer of cosmetic head shape. For example, in Asia, where the normal cranial shape is mesocephalic or brachycephalic and often with a planar occiput, requests for its aesthetic correction are increasingly common. Accordingly, the author developed a minimally invasive occiput augmentation using methylmethacrylate. In this study, the indications for aesthetic occiput contouring were planar occiput, left-right asymmetric occiput, and grooved occiput. Under local anesthesia, soft methylmethacrylate is subperiosteally inserted through a small incision (about 5-cm length), manually and precisely contoured in situ through the scalp to the desired occipital shape. All is performed as an outpatient procedure, and a quick recovery is the case. Between March 2007 and October 2013, 959 patients received such aesthetic occiput augmentation. The mean follow-up period was 49 months (range, 3-84 months). Nearly all patients were satisfied with the outcome, and complications were very rare. Only 5 patients (0.5%) needed additional corrective procedures. The author has concluded that aesthetic occiput augmentation using methylmethacrylate yields consistent, predictable, and satisfactory results. Additional long-term follow-up is required for a final conclusion, however. PMID:25569386

  10. Stress Relaxation of Magnetorheological Fluids

    NASA Astrophysics Data System (ADS)

    Li, W. H.; Chen, G.; Yeo, S. H.; Du, H.

    In this paper, the experimental and modeling study and analysis of the stress relaxation characteristics of magnetorheological (MR) fluids under step shear are presented. The experiments are carried out using a rheometer with parallel-plate geometry. The applied strain varies from 0.01% to 100%, covering both the pre-yield and post-yield regimes. The effects of step strain, field strength, and temperature on the stress modulus are addressed. For small step strain ranges, the stress relaxation modulus G(t,γ) is independent of step strain, where MR fluids behave as linear viscoelastic solids. For large step strain ranges, the stress relaxation modulus decreases gradually with increasing step strain. Morever, the stress relaxation modulus G(t,γ) was found to obey time-strain factorability. That is, G(t,γ) can be represented as the product of a linear stress relaxation G(t) and a strain-dependent damping function h(γ). The linear stress relaxation modulus is represented as a three-parameter solid viscoelastic model, and the damping function h(γ) has a sigmoidal form with two parameters. The comparison between the experimental results and the model-predicted values indicates that this model can accurately describe the relaxation behavior of MR fluids under step strains.

  11. A unified approach to an augmented Burgers equation for the propagation of sonic booms.

    PubMed

    Yamamoto, Masafumi; Hashimoto, Atsushi; Aoyama, Takashi; Sakai, Takeharu

    2015-04-01

    Nonlinear propagation through a relaxing atmosphere of pressure disturbances extracted from a computational fluid dynamics (CFD) solution of the flow around a supersonic aircraft is simulated using an augmented Burgers equation. The effects of nonlinearity, geometrical spreading, atmospheric inhomogeneity, thermoviscous attenuation, and molecular vibration relaxation are taken into account. The augmented Burgers equation used for sonic boom propagation calculations is often solved by the operator splitting method, but numerical difficulties arise with this approach when dissipation is not effective. By re-examining the solution algorithms for the augmented Burgers equation, a stable method for handling the relaxation effect has been developed. This approach can handle the Burgers equation in a unified manner without operator splitting and, therefore, the resulting scheme is twice as fast as the original one. The approach is validated by comparing it with an analytical solution and a detailed CFD of dispersed plane wave propagation. In addition, a rise time prediction of low-boom supersonic aircraft is demonstrated. PMID:25920838

  12. Elastoviscoplastic Relaxation of Craters on Ganymede and Callisto: Implications for Thermal Evolution

    NASA Astrophysics Data System (ADS)

    Dombard, A. J.; McKinnon, W. B.

    1999-09-01

    We report continuing efforts to simulate crater relaxation on Ganymede and Callisto. The finite element method is used, employing an elastoviscoplastic (EVP) rheological model. Adding elastic and plastic (a continuum approximation for discrete, brittle faulting) components to the usually modeled viscous creep provides extra avenues through which topography can be relaxed. Hence, EVP relaxation can, in principle, proceed faster than viscous relaxation. Driving stresses are small enough, however, compared to the elastic and plastic strengths that these extra components do not augment relaxation much, and the process is strongly determined by the creep properties of the near-surface. Indeed, plastic strains associated with floor uplift appear limited to less than ~ 1%; such low strain faulting may not be visible. Radial faults seen in some dome craters are thus likely not due to relaxation, but to prompt collapse or dome formation. In our simulations, we use the most recent data for fresh crater dimensions and the most recently determined rheological parameters for water ice, including a grain size sensitive, grain boundary sliding creep mechanism. For reasonable choices of input parameters (crater diameter, thermal structure, and grain size), we find relaxation times (the time needed for initial apparent crater depth to decrease by a factor of 1/e) that span the lifetimes of the satellites' surfaces. For near-zero heat flow, relaxation times can exceed the age of the solar system, even for large craters (a finding that contrasts with previous analyses). For high heat flow (approaching 10 mW m(-2) ), relaxation times for large craters can be on the order of years. This large variation in relaxation times will permit the simulation of the full range of observed crater relaxation states, with the goal of piecing together more refined thermal histories for Ganymede and Callisto. Funding provided by a NASA GSRP Fellowship to AJD.

  13. "Basic MR Relaxation Mechanisms & Contrast Agent Design"

    PubMed Central

    De León-Rodríguez, Luis M.; Martins, André F.; Pinho, Marco; Rofsky, Neil; Sherry, A. Dean

    2015-01-01

    The diagnostic capabilities of magnetic resonance imaging (MRI) have undergone continuous and substantial evolution by virtue of hardware and software innovations and the development and implementation of exogenous contrast media. Thirty years since the first MRI contrast agent was approved for clinical use, a reliance on MR contrast media persists largely to improve image quality with higher contrast resolution and to provide additional functional characterization of normal and abnormal tissues. Further development of MR contrast media is an important component in the quest for continued augmentation of diagnostic capabilities. In this review we will detail the many important considerations when pursuing the design and use of MR contrast media. We will offer a perspective on the importance of chemical stability, particularly kinetic stability, and how this influences one's thinking about the safety of metal-ligand based contrast agents. We will discuss the mechanisms involved in magnetic resonance relaxation in the context of probe design strategies. A brief description of currently available contrast agents will be accompanied by an in-depth discussion that highlights promising MRI contrast agents in development for future clinical and research applications. Our intention is to give a diverse audience an improved understanding of the factors involved in developing new types of safe and highly efficient MR contrast agents and, at the same time, provide an appreciation of the insights into physiology and disease that newer types of responsive agents can provide. PMID:25975847

  14. Simulation of DNA Supercoil Relaxation.

    PubMed

    Ivenso, Ikenna D; Lillian, Todd D

    2016-05-24

    Several recent single-molecule experiments observe the response of supercoiled DNA to nicking endonucleases and topoisomerases. Typically in these experiments, indirect measurements of supercoil relaxation are obtained by observing the motion of a large micron-sized bead. The bead, which also serves to manipulate DNA, experiences significant drag and thereby obscures supercoil dynamics. Here we employ our discrete wormlike chain model to bypass experimental limitations and simulate the dynamic response of supercoiled DNA to a single strand nick. From our simulations, we make three major observations. First, extension is a poor dynamic measure of supercoil relaxation; in fact, the linking number relaxes so fast that it cannot have much impact on extension. Second, the rate of linking number relaxation depends upon its initial partitioning into twist and writhe as determined by tension. Third, the extensional response strongly depends upon the initial position of plectonemes. PMID:27224483

  15. Webizing mobile augmented reality content

    NASA Astrophysics Data System (ADS)

    Ahn, Sangchul; Ko, Heedong; Yoo, Byounghyun

    2014-01-01

    This paper presents a content structure for building mobile augmented reality (AR) applications in HTML5 to achieve a clean separation of the mobile AR content and the application logic for scaling as on the Web. We propose that the content structure contains the physical world as well as virtual assets for mobile AR applications as document object model (DOM) elements and that their behaviour and user interactions are controlled through DOM events by representing objects and places with a uniform resource identifier. Our content structure enables mobile AR applications to be seamlessly developed as normal HTML documents under the current Web eco-system.

  16. Augmented reality in medical education?

    PubMed

    Kamphuis, Carolien; Barsom, Esther; Schijven, Marlies; Christoph, Noor

    2014-09-01

    Learning in the medical domain is to a large extent workplace learning and involves mastery of complex skills that require performance up to professional standards in the work environment. Since training in this real-life context is not always possible for reasons of safety, costs, or didactics, alternative ways are needed to achieve clinical excellence. Educational technology and more specifically augmented reality (AR) has the potential to offer a highly realistic situated learning experience supportive of complex medical learning and transfer. AR is a technology that adds virtual content to the physical real world, thereby augmenting the perception of reality. Three examples of dedicated AR learning environments for the medical domain are described. Five types of research questions are identified that may guide empirical research into the effects of these learning environments. Up to now, empirical research mainly appears to focus on the development, usability and initial implementation of AR for learning. Limited review results reflect the motivational value of AR, its potential for training psychomotor skills and the capacity to visualize the invisible, possibly leading to enhanced conceptual understanding of complex causality. PMID:24464832

  17. PRP Augmentation for ACL Reconstruction.

    PubMed

    Andriolo, Luca; Di Matteo, Berardo; Kon, Elizaveta; Filardo, Giuseppe; Venieri, Giulia; Marcacci, Maurilio

    2015-01-01

    Current research is investigating new methods to enhance tissue healing to speed up recovery time and decrease the risk of failure in Anterior Cruciate Ligament (ACL) reconstructive surgery. Biological augmentation is one of the most exploited strategies, in particular the application of Platelet Rich Plasma (PRP). Aim of the present paper is to systematically review all the preclinical and clinical papers dealing with the application of PRP as a biological enhancer during ACL reconstructive surgery. Thirty-two studies were included in the present review. The analysis of the preclinical evidence revealed that PRP was able to improve the healing potential of the tendinous graft both in terms of histological and biomechanical performance. Looking at the available clinical evidence, results were not univocal. PRP administration proved to be a safe procedure and there were some evidences that it could favor the donor site healing in case of ACL reconstruction with patellar tendon graft and positively contribute to graft maturation over time, whereas the majority of the papers did not show beneficial effects in terms of bony tunnels/graft area integration. Furthermore, PRP augmentation did not provide superior functional results at short term evaluation. PMID:26064903

  18. PRP Augmentation for ACL Reconstruction

    PubMed Central

    Di Matteo, Berardo; Kon, Elizaveta; Marcacci, Maurilio

    2015-01-01

    Current research is investigating new methods to enhance tissue healing to speed up recovery time and decrease the risk of failure in Anterior Cruciate Ligament (ACL) reconstructive surgery. Biological augmentation is one of the most exploited strategies, in particular the application of Platelet Rich Plasma (PRP). Aim of the present paper is to systematically review all the preclinical and clinical papers dealing with the application of PRP as a biological enhancer during ACL reconstructive surgery. Thirty-two studies were included in the present review. The analysis of the preclinical evidence revealed that PRP was able to improve the healing potential of the tendinous graft both in terms of histological and biomechanical performance. Looking at the available clinical evidence, results were not univocal. PRP administration proved to be a safe procedure and there were some evidences that it could favor the donor site healing in case of ACL reconstruction with patellar tendon graft and positively contribute to graft maturation over time, whereas the majority of the papers did not show beneficial effects in terms of bony tunnels/graft area integration. Furthermore, PRP augmentation did not provide superior functional results at short term evaluation. PMID:26064903

  19. Striae distensae after subfascial breast augmentation.

    PubMed

    Keramidas, Evangelos; Rodopoulou, Stavroula

    2008-03-01

    Striae distensae or stretch marks after breast augmentation are a rare complication. To date, 10 cases have been published. In seven of these cases, the implant was placed in a subglandular position and in the other three cases, placement was submuscular. Two cases of stretch marks in two young nulliparous women who underwent subfacial breast augmentation are presented. To the best of the authors' knowledge, this is the first report of striae distensae after subfascial breast augmentation. PMID:18043962

  20. Relaxation schemes for Chebyshev spectral multigrid methods

    NASA Technical Reports Server (NTRS)

    Kang, Yimin; Fulton, Scott R.

    1993-01-01

    Two relaxation schemes for Chebyshev spectral multigrid methods are presented for elliptic equations with Dirichlet boundary conditions. The first scheme is a pointwise-preconditioned Richardson relaxation scheme and the second is a line relaxation scheme. The line relaxation scheme provides an efficient and relatively simple approach for solving two-dimensional spectral equations. Numerical examples and comparisons with other methods are given.

  1. Convex-relaxed kernel mapping for image segmentation.

    PubMed

    Ben Salah, Mohamed; Ben Ayed, Ismail; Jing Yuan; Hong Zhang

    2014-03-01

    This paper investigates a convex-relaxed kernel mapping formulation of image segmentation. We optimize, under some partition constraints, a functional containing two characteristic terms: 1) a data term, which maps the observation space to a higher (possibly infinite) dimensional feature space via a kernel function, thereby evaluating nonlinear distances between the observations and segments parameters and 2) a total-variation term, which favors smooth segment surfaces (or boundaries). The algorithm iterates two steps: 1) a convex-relaxation optimization with respect to the segments by solving an equivalent constrained problem via the augmented Lagrange multiplier method and 2) a convergent fixed-point optimization with respect to the segments parameters. The proposed algorithm can bear with a variety of image types without the need for complex and application-specific statistical modeling, while having the computational benefits of convex relaxation. Our solution is amenable to parallelized implementations on graphics processing units (GPUs) and extends easily to high dimensions. We evaluated the proposed algorithm with several sets of comprehensive experiments and comparisons, including: 1) computational evaluations over 3D medical-imaging examples and high-resolution large-size color photographs, which demonstrate that a parallelized implementation of the proposed method run on a GPU can bring a significant speed-up and 2) accuracy evaluations against five state-of-the-art methods over the Berkeley color-image database and a multimodel synthetic data set, which demonstrates competitive performances of the algorithm. PMID:24723519

  2. Economic evaluation of flying-qualities design criteria for a transport configured with relaxed static stability

    NASA Technical Reports Server (NTRS)

    Sliwa, S. M.

    1980-01-01

    Direct constrained parameter optimization was used to optimally size a medium range transport for minimum direct operating cost. Several stability and control constraints were varied to study the sensitivity of the configuration to specifying the unaugmented flying qualities of transports designed to take maximum advantage of relaxed static stability augmentation systems. Additionally, a number of handling qualities related design constants were studied with respect to their impact on the design.

  3. Phase transitions in semidefinite relaxations

    PubMed Central

    Javanmard, Adel; Montanari, Andrea; Ricci-Tersenghi, Federico

    2016-01-01

    Statistical inference problems arising within signal processing, data mining, and machine learning naturally give rise to hard combinatorial optimization problems. These problems become intractable when the dimensionality of the data is large, as is often the case for modern datasets. A popular idea is to construct convex relaxations of these combinatorial problems, which can be solved efficiently for large-scale datasets. Semidefinite programming (SDP) relaxations are among the most powerful methods in this family and are surprisingly well suited for a broad range of problems where data take the form of matrices or graphs. It has been observed several times that when the statistical noise is small enough, SDP relaxations correctly detect the underlying combinatorial structures. In this paper we develop asymptotic predictions for several detection thresholds, as well as for the estimation error above these thresholds. We study some classical SDP relaxations for statistical problems motivated by graph synchronization and community detection in networks. We map these optimization problems to statistical mechanics models with vector spins and use nonrigorous techniques from statistical mechanics to characterize the corresponding phase transitions. Our results clarify the effectiveness of SDP relaxations in solving high-dimensional statistical problems. PMID:27001856

  4. Phase transitions in semidefinite relaxations.

    PubMed

    Javanmard, Adel; Montanari, Andrea; Ricci-Tersenghi, Federico

    2016-04-19

    Statistical inference problems arising within signal processing, data mining, and machine learning naturally give rise to hard combinatorial optimization problems. These problems become intractable when the dimensionality of the data is large, as is often the case for modern datasets. A popular idea is to construct convex relaxations of these combinatorial problems, which can be solved efficiently for large-scale datasets. Semidefinite programming (SDP) relaxations are among the most powerful methods in this family and are surprisingly well suited for a broad range of problems where data take the form of matrices or graphs. It has been observed several times that when the statistical noise is small enough, SDP relaxations correctly detect the underlying combinatorial structures. In this paper we develop asymptotic predictions for several detection thresholds, as well as for the estimation error above these thresholds. We study some classical SDP relaxations for statistical problems motivated by graph synchronization and community detection in networks. We map these optimization problems to statistical mechanics models with vector spins and use nonrigorous techniques from statistical mechanics to characterize the corresponding phase transitions. Our results clarify the effectiveness of SDP relaxations in solving high-dimensional statistical problems. PMID:27001856

  5. Interaction of neutrophils with vascular smooth muscle: identification of a neutrophil-derived relaxing factor.

    PubMed

    Rimele, T J; Sturm, R J; Adams, L M; Henry, D E; Heaslip, R J; Weichman, B M; Grimes, D

    1988-04-01

    Experiments were designed to study the interaction of rat peritoneal neutrophils with the vascular smooth muscle of the rat aorta. Rings of aorta, suspended in 10-ml organ chambers containing a physiologic salt solution, were precontracted with phenylephrine. Neutrophils (1 X 10(5) -4 X 10(7) cells/organ chamber) caused a cell number-dependent relaxation of the rat aorta that was augmented by superoxide dismutase (100 U/ml) or changing the oxygen content from 95 to 21%. The neutrophil-induced smooth muscle relaxation occurred in rings with and without endothelium and in rings precontracted with increasing concentrations of phenylephrine, prostaglandin F2 alpha or KCI. Catalase (1000 U/ml) and mannitol (1 X 10(-3) M) did not block the neutrophil-induced relaxation, whereas phenazine methosulfate (1 X 10(-5) M), hydroquinone (3 X 10(-5) M) and methylene blue (1 X 10(-5) M) reversed the neutrophil-induced relaxation. Pre-exposure of endothelium-rubbed rings to neutrophils (2 X 10(7) cells/organ chamber; 15 min) depressed the subsequent concentration-response curve to phenylephrine but augmented the relaxation induced by the phosphodiesterase inhibitor zaprinast (1 X 10(-5) M). The effluent from a column restraining the neutrophils induced a relaxation of endothelium-rubbed aortic rings that was prevented by methylene blue (1 X 10(-5) M). These results demonstrate that rat neutrophils release a factor that has a pharmacologic profile similar to that previously reported for the relaxing factor released from the vascular endothelium. PMID:3129547

  6. LOFT Augmented Operator Capability Program

    SciTech Connect

    Hollenbeck, D.A.; Krantz, E.A.; Hunt, G.L.; Meyer, O.R.

    1980-01-01

    The outline of the LOFT Augmented Operator Capability Program is presented. This program utilizes the LOFT (Loss-of-Fluid Test) reactor facility which is located at the Idaho National Engineering Laboratory and the LOFT operational transient experiment series as a test bed for methods of enhancing the reactor operator's capability for safer operation. The design of an Operational Diagnotics and Display System is presented which was backfit to the existing data acquisition computers. Basic color-graphic displays of the process schematic and trend type are presented. In addition, displays were developed and are presented which represent safety state vector information. A task analysis method was applied to LOFT reactor operating procedures to test its usefulness in defining the operator's information needs and workload.

  7. Folate augmentation of antidepressant response.

    PubMed

    Owen, R T

    2013-12-01

    The use of two antidepressants from the initiation of treatment in major depressive disorder has been investigated in several recent studies and forms a paradigm shift in the pharmacotherapy of the condition. Several, but not all, trials have claimed improved response and remission rates with the combinations as opposed to monotherapy. The use of folate preparations (folic and folinic acid and l-meth-ylfolate) have shown effective augmentation of antidepressant response in a variety of controlled and open-label settings in patients with normo- and hypofolatemic status. Several recent trials using L-methylfolate, the active and more bioavailable form of folic acid, have shown promising adjunctive use with a well-tolerated adverse event profile. PMID:24524097

  8. Augmented Reality and Mobile Art

    NASA Astrophysics Data System (ADS)

    Gwilt, Ian

    The combined notions of augmented-reality (AR) and mobile art are based on the amalgamation of a number of enabling technologies including computer imaging, emergent display and tracking systems and the increased computing-power in hand-held devices such as Tablet PCs, smart phones, or personal digital assistants (PDAs) which have been utilized in the making of works of art. There is much published research on the technical aspects of AR and the ongoing work being undertaken in the development of faster more efficient AR systems [1] [2]. In this text I intend to concentrate on how AR and its associated typologies can be applied in the context of new media art practices, with particular reference to its application on hand-held or mobile devices.

  9. Sensory Augmentation for the Blind

    PubMed Central

    Kärcher, Silke M.; Fenzlaff, Sandra; Hartmann, Daniela; Nagel, Saskia K.; König, Peter

    2012-01-01

    Common navigational aids used by blind travelers during large-scale navigation divert attention away from important cues of the immediate environment (i.e., approaching vehicles). Sensory augmentation devices, relying on principles similar to those at work in sensory substitution, can potentially bypass the bottleneck of attention through sub-cognitive implementation of a set of rules coupling motor actions with sensory stimulation. We provide a late blind subject with a vibrotactile belt that continually signals the direction of magnetic north. The subject completed a set of behavioral tests before and after an extended training period. The tests were complemented by questionnaires and interviews. This newly supplied information improved performance on different time scales. In a pointing task we demonstrate an instant improvement of performance based on the signal provided by the device. Furthermore, the signal was helpful in relevant daily tasks, often complicated for the blind, such as keeping a direction over longer distances or taking shortcuts in familiar environments. A homing task with an additional attentional load demonstrated a significant improvement after training. The subject found the directional information highly expedient for the adjustment of his inner maps of familiar environments and describes an increase in his feeling of security when exploring unfamiliar environments with the belt. The results give evidence for a firm integration of the newly supplied signals into the behavior of this late blind subject with better navigational performance and more courageous behavior in unfamiliar environments. Most importantly, the complementary information provided by the belt lead to a positive emotional impact with enhanced feeling of security. The present experimental approach demonstrates the positive potential of sensory augmentation devices for the help of handicapped people. PMID:22403535

  10. Shoreline relaxation at pocket beaches

    NASA Astrophysics Data System (ADS)

    Turki, Imen; Medina, Raul; Kakeh, Nabil; González, Mauricio

    2015-09-01

    A new physical concept of relaxation time is introduced in this research as the time required for the beach to dissipate its initial perturbation. This concept is investigated using a simple beach-evolution model of shoreline rotation at pocket beaches, based on the assumption that the instantaneous change of the shoreline plan-view shape depends on the long-term equilibrium plan-view shape. The expression of relaxation time is developed function of the energy conditions and the physical characteristics of the beach; it increases at longer beaches having coarse sediments and experiencing low-energy conditions. The relaxation time, calculated by the developed model, is validated by the shoreline observations extracted from video images at two artificially embayed beaches of Barcelona (NW Mediterranean) suffering from perturbations of sand movement and a nourishment project. This finding is promising to estimate the shoreline response and useful to improve our understanding of the dynamic of pocket beaches and their stability.

  11. Multigrid Methods for Mesh Relaxation

    SciTech Connect

    O'Brien, M J

    2006-06-12

    When generating a mesh for the initial conditions for a computer simulation, you want the mesh to be as smooth as possible. A common practice is to use equipotential mesh relaxation to smooth out a distorted computational mesh. Typically a Laplace-like equation is set up for the mesh coordinates and then one or more Jacobi iterations are performed to relax the mesh. As the zone count gets really large, the Jacobi iteration becomes less and less effective and we are stuck with our original unrelaxed mesh. This type of iteration can only damp high frequency errors and the smooth errors remain. When the zone count is large, almost everything looks smooth so relaxation cannot solve the problem. In this paper we examine a multigrid technique which effectively smooths out the mesh, independent of the number of zones.

  12. Ellipsoidal Relaxation of Deformed Vesicles

    NASA Astrophysics Data System (ADS)

    Yu, Miao; Lira, Rafael B.; Riske, Karin A.; Dimova, Rumiana; Lin, Hao

    2015-09-01

    Theoretical analysis and experimental quantification on the ellipsoidal relaxation of vesicles are presented. The current work reveals the simplicity and universal aspects of this process. The Helfrich formula is shown to apply to the dynamic relaxation of moderate-to-high tension membranes, and a closed-form solution is derived which predicts the vesicle aspect ratio as a function of time. Scattered data are unified by a time scale, which leads to a similarity behavior, governed by a distinctive solution for each vesicle type. Two separate regimes in the relaxation are identified, namely, the "entropic" and the "constant-tension" regimes. The bending rigidity and the initial membrane tension can be simultaneously extracted from the data analysis, posing the current approach as an effective means for the mechanical analysis of biomembranes.

  13. Relaxed Poisson cure rate models.

    PubMed

    Rodrigues, Josemar; Cordeiro, Gauss M; Cancho, Vicente G; Balakrishnan, N

    2016-03-01

    The purpose of this article is to make the standard promotion cure rate model (Yakovlev and Tsodikov, ) more flexible by assuming that the number of lesions or altered cells after a treatment follows a fractional Poisson distribution (Laskin, ). It is proved that the well-known Mittag-Leffler relaxation function (Berberan-Santos, ) is a simple way to obtain a new cure rate model that is a compromise between the promotion and geometric cure rate models allowing for superdispersion. So, the relaxed cure rate model developed here can be considered as a natural and less restrictive extension of the popular Poisson cure rate model at the cost of an additional parameter, but a competitor to negative-binomial cure rate models (Rodrigues et al., ). Some mathematical properties of a proper relaxed Poisson density are explored. A simulation study and an illustration of the proposed cure rate model from the Bayesian point of view are finally presented. PMID:26686485

  14. Global relaxation of superconducting qubits

    SciTech Connect

    Ojanen, T.; Niskanen, A. O.; Nakamura, Y.; Abdumalikov, A. A. Jr.

    2007-09-01

    We consider coupled quantum two-state systems (qubits) exposed to a global relaxation process. The global relaxation refers to the assumption that qubits are coupled to the same quantum bath with approximately equal strengths, appropriate for long-wavelength environmental fluctuations. We show that interactions do not spoil the picture of Dicke's subradiant and super-radiant states where quantum interference effects lead to striking deviations from the independent relaxation picture. Remarkably, the system possess a stable entangled state and a state decaying faster than single qubit excitations. We propose a scheme for how these effects can be experimentally accessed in superconducting flux qubits and, possibly, used in constructing long-lived entangled states.

  15. A mixed relaxed clock model

    PubMed Central

    2016-01-01

    Over recent years, several alternative relaxed clock models have been proposed in the context of Bayesian dating. These models fall in two distinct categories: uncorrelated and autocorrelated across branches. The choice between these two classes of relaxed clocks is still an open question. More fundamentally, the true process of rate variation may have both long-term trends and short-term fluctuations, suggesting that more sophisticated clock models unfolding over multiple time scales should ultimately be developed. Here, a mixed relaxed clock model is introduced, which can be mechanistically interpreted as a rate variation process undergoing short-term fluctuations on the top of Brownian long-term trends. Statistically, this mixed clock represents an alternative solution to the problem of choosing between autocorrelated and uncorrelated relaxed clocks, by proposing instead to combine their respective merits. Fitting this model on a dataset of 105 placental mammals, using both node-dating and tip-dating approaches, suggests that the two pure clocks, Brownian and white noise, are rejected in favour of a mixed model with approximately equal contributions for its uncorrelated and autocorrelated components. The tip-dating analysis is particularly sensitive to the choice of the relaxed clock model. In this context, the classical pure Brownian relaxed clock appears to be overly rigid, leading to biases in divergence time estimation. By contrast, the use of a mixed clock leads to more recent and more reasonable estimates for the crown ages of placental orders and superorders. Altogether, the mixed clock introduced here represents a first step towards empirically more adequate models of the patterns of rate variation across phylogenetic trees. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’. PMID:27325829

  16. A mixed relaxed clock model.

    PubMed

    Lartillot, Nicolas; Phillips, Matthew J; Ronquist, Fredrik

    2016-07-19

    Over recent years, several alternative relaxed clock models have been proposed in the context of Bayesian dating. These models fall in two distinct categories: uncorrelated and autocorrelated across branches. The choice between these two classes of relaxed clocks is still an open question. More fundamentally, the true process of rate variation may have both long-term trends and short-term fluctuations, suggesting that more sophisticated clock models unfolding over multiple time scales should ultimately be developed. Here, a mixed relaxed clock model is introduced, which can be mechanistically interpreted as a rate variation process undergoing short-term fluctuations on the top of Brownian long-term trends. Statistically, this mixed clock represents an alternative solution to the problem of choosing between autocorrelated and uncorrelated relaxed clocks, by proposing instead to combine their respective merits. Fitting this model on a dataset of 105 placental mammals, using both node-dating and tip-dating approaches, suggests that the two pure clocks, Brownian and white noise, are rejected in favour of a mixed model with approximately equal contributions for its uncorrelated and autocorrelated components. The tip-dating analysis is particularly sensitive to the choice of the relaxed clock model. In this context, the classical pure Brownian relaxed clock appears to be overly rigid, leading to biases in divergence time estimation. By contrast, the use of a mixed clock leads to more recent and more reasonable estimates for the crown ages of placental orders and superorders. Altogether, the mixed clock introduced here represents a first step towards empirically more adequate models of the patterns of rate variation across phylogenetic trees.This article is part of the themed issue 'Dating species divergences using rocks and clocks'. PMID:27325829

  17. Relaxation dynamics of branched polymers

    NASA Astrophysics Data System (ADS)

    Ghosh, Arnav

    The Rouse model for star polymers was successfully derived by solving the differential equations governing the net force acting on each bead in a star polymer chain. As opposed to a linear polymer, where we have N unique roots for N beads, in the case of star polymers, there are only 2 Na+1 unique roots and all odd unique roots (except the last root corresponding to the branch point) starting with the first root have a multiplicity of f-1. The relaxation time of the pth unique Rouse mode of a star polymer varies as (2Na + 1)2/p2. Since alternate Rouse modes in a star polymer have a multiplicity of f-1, they add to the terminal modulus of the star polymers and the terminal modulus, G(tau) ends up being proportional to f-1 (besides being inversely proportional to N, which is also the case with linear polymers). A self-consistent theory for the relaxation of entangled star polymers was developed based on the work done by Colby and Rubinstein on linear blends. This theory considers the duality of relaxation dynamics (direct stress relaxation and indirect relaxation by release of constraints) and models the relaxation due to constraint release R(t) based on Dean's approach in solving the vibration frequencies of glassy chains with random spring constants. In our case, the mobilities of beads were considered to be random and based on the relative weight of the prefactor of a Maxwell function, a group of which was fitted to the stress relaxation function mu(t) of a star polymer (proposed and derived by Doi). The tube dilation model for star and comb polymers was investigated in detail and predictions compared to rheological data from polypropylene, polybutadiene and polystyrene comb polymers along with PEP star polymers. The relaxation time from the Tube Dilation Model was compared with the classical Tube Model and was shown to have an extra power dependence on the fraction of the comb backbone.

  18. Statistical mechanics of violent relaxation

    NASA Technical Reports Server (NTRS)

    Spergel, David N.; Hernquist, Lars

    1992-01-01

    We propose a functional that is extremized through violent relaxation. It is based on the Ansatz that the wave-particle scattering during violent dynamical processes can be approximated as a sequence of discrete scattering events that occur near a particle's perigalacticon. This functional has an extremum whose structure closely resembles that of spheroidal stellar systems such as elliptical galaxies. The results described here, therefore, provide a simple framework for understanding the physical nature of violent relaxation and support the view that galaxies are structured in accord with fundamental statistical principles.

  19. Status report of RMS active damping augmentation

    NASA Technical Reports Server (NTRS)

    Gilbert, Mike; Demeo, Martha E.

    1993-01-01

    A status report of Remote Manipulator System (RMS) active damping augmentation is presented. Topics covered include: active damping augmentation; benefits of RMS ADA; simulated payload definition; sensor and actuator definition; ADA control law design; Shuttle Engineering Simulator (SES) real-time simulation; and astronaut evaluation.

  20. Vertebral Augmentation for Osteoporotic Compression Fractures.

    PubMed

    Richmond, Bradford J

    2016-01-01

    Vertebral augmentation procedures such as vertebroplasty and kyphoplasty were developed to reduce pain and improve quality of life for patients with osteoporotic vertebral compression fractures. However, the use of vertebral augmentation has been debated and questioned since its inception. This article addresses some of these issues. PMID:26490134

  1. Enhancing Education through Mobile Augmented Reality

    ERIC Educational Resources Information Center

    Joan, D. R. Robert

    2015-01-01

    In this article, the author has discussed about the Mobile Augmented Reality and enhancing education through it. The aim of the present study was to give some general information about mobile augmented reality which helps to boost education. Purpose of the current study reveals the mobile networks which are used in the institution campus as well…

  2. Augmented Reality for Close Quarters Combat

    ScienceCinema

    None

    2014-06-23

    Sandia National Laboratories has developed a state-of-the-art augmented reality training system for close-quarters combat (CQB). This system uses a wearable augmented reality system to place the user in a real environment while engaging enemy combatants in virtual space (Boston Dynamics DI-Guy). Umbra modeling and simulation environment is used to integrate and control the AR system.

  3. From Augmentation Media to Meme Media.

    ERIC Educational Resources Information Center

    Tanaka, Yuzuru

    Computers as meta media are now evolving from augmentation media vehicles to meme media vehicles. While an augmentation media system provides a seamlessly integrated environment of various tools and documents, meme media system provides further functions to edit and distribute tools and documents. Documents and tools on meme media can easily…

  4. Augmented Reality for Close Quarters Combat

    SciTech Connect

    2013-09-20

    Sandia National Laboratories has developed a state-of-the-art augmented reality training system for close-quarters combat (CQB). This system uses a wearable augmented reality system to place the user in a real environment while engaging enemy combatants in virtual space (Boston Dynamics DI-Guy). Umbra modeling and simulation environment is used to integrate and control the AR system.

  5. Performance of a self-augmented railgun

    SciTech Connect

    Burton, R.L.; Witherspoon, F.D.; Goldstein, S.A. )

    1991-10-01

    The accelerating force of a railgun 1/2{ital L}{prime}{ital I}{sup 2}{sub {ital a}} can be increased by augmenting the self-induced magnetic field created by the armature current. Augmentation fields can be produced by external current coils or, as is done here, by shorting the railgun muzzle, and using the gun rails as the augmentation coil. Experimental results are presented for a 3.6-m railgun operated in this self-augmented mode, and effective inductance gradients are achieved which are as much as 9.3 times that of the unaugmented gun. A circuit model is presented which explains features of the measured shunt current and voltage. It is concluded that self-augmentation is an effective way to reduce ohmic heating in the armature of a railgun.

  6. Irradiated homologous costal cartilage for augmentation rhinoplasty

    SciTech Connect

    Lefkovits, G. )

    1990-10-01

    Although the ideal reconstructive material for augmentation rhinoplasty continues to challenge plastic surgeons, there exists no report in the literature that confines the use of irradiated homologous costal cartilage, first reported by Dingman and Grabb in 1961, to dorsal nasal augmentation. The purpose of this paper is to present a retrospective analysis of the author's experience using irradiated homologous costal cartilage in augmentation rhinoplasty. Twenty-seven dorsal nasal augmentations were performed in 24 patients between 16 and 49 years of age with a follow-up ranging from 1 to 27 months. Good-to-excellent results were achieved in 83.3% (20 of 24). Poor results requiring revision were found in 16.7% (4 of 24). Complication rates included 7.4% infection (2 of 27) and 14.8% warping (4 of 27). The resorption rate was zero. These results compare favorably with other forms of nasal augmentation. Advantages and disadvantages of irradiated homologous costal cartilage are discussed.

  7. NMR Relaxation and Petrophysical Properties

    NASA Astrophysics Data System (ADS)

    Fleury, Marc

    2011-03-01

    NMR relaxation is routinely used in the field of geosciences to give basic petrophysical properties such as porosity, pore size distribution, saturation etc. In this tutorial, we focus on the pore size distribution deduced from NMR. We recall the basic principle used in the interpretation of the NMR signal and compare the results with other standard petrophysical techniques such as mercury pore size distribution, BET specific surface measurements, thin section visualizations. The NMR pore size distribution is a unique information available on water saturated porous media and can give similar results as MICP in certain situations. The scaling of NMR relaxation time distribution (s) into pore sizes (μm) requires the knowledge of the surface relaxivity (μm/s) and we recommend using specific surface measurements as an independent determination of solid surface areas. With usual surface relaxivities, the NMR technique can explore length-scales starting from nano-meters and ending around 100 μm. Finally, we will introduce briefly recent techniques sensitive to the pore to pore diffusional exchange, providing new information on the connectivity of the pore network, but showing another possibility of discrepancy in the determination of pore size distribution with standard techniques.

  8. Distributed Relaxation for Conservative Discretizations

    NASA Technical Reports Server (NTRS)

    Diskin, Boris; Thomas, James L.

    2001-01-01

    A multigrid method is defined as having textbook multigrid efficiency (TME) if the solutions to the governing system of equations are attained in a computational work that is a small (less than 10) multiple of the operation count in one target-grid residual evaluation. The way to achieve this efficiency is the distributed relaxation approach. TME solvers employing distributed relaxation have already been demonstrated for nonconservative formulations of high-Reynolds-number viscous incompressible and subsonic compressible flow regimes. The purpose of this paper is to provide foundations for applications of distributed relaxation to conservative discretizations. A direct correspondence between the primitive variable interpolations for calculating fluxes in conservative finite-volume discretizations and stencils of the discretized derivatives in the nonconservative formulation has been established. Based on this correspondence, one can arrive at a conservative discretization which is very efficiently solved with a nonconservative relaxation scheme and this is demonstrated for conservative discretization of the quasi one-dimensional Euler equations. Formulations for both staggered and collocated grid arrangements are considered and extensions of the general procedure to multiple dimensions are discussed.

  9. Ellipsoidal relaxation of electrodeformed vesicles

    NASA Astrophysics Data System (ADS)

    Yu, Miao; Lin, Hao; Lira, Rafael; Dimova, Rumiana; Riske, Karin

    2015-11-01

    Electrodeformation has been extensively applied to investigate the mechanical behavior of vesicles and cells. While the deformation process often exhibits complex behavior and reveals interesting physics, the relaxation process post-pulsation is equally intriguing yet less frequently studied. In this work theoretical analysis and experimental quantification on the ellipsoidal relaxation of vesicles are presented, which reveal the simplicity and universal aspects of this process. The Helfrich formula, which is derived only for equilibrated shapes, is shown to be applicable to dynamic situations such as in relaxation. A closed-form solution is derived which predicts the vesicle aspect ratio as a function of time. Scattered data are unified by a timescale, which leads to a similarity behavior, governed by a distinctive solution for each vesicle type. Two separate regimes in the relaxation are identified, namely, the ``entropic'' and the ``constant-tension'' regime. The bending rigidity and the initial membrane tension can be simultaneously extracted from the data/model analysis, posing the current approach as an effective means for the mechanical analysis of biomembranes.

  10. Spin relaxation in disordered media

    NASA Astrophysics Data System (ADS)

    Dzheparov, F. S.

    2011-10-01

    A review is given on theoretical grounds and typical experimental appearances of spin dynamics and relaxation in solids containing randomly distributed nuclear and/or electronic spins. Brief content is as follows. Disordered and magnetically diluted systems. General outlines of the spin transport theory. Random walks in disordered systems (RWDS). Observable values in phase spin relaxation, free induction decay (FID). Interrelation of longitudinal and transversal relaxation related to dynamics of occupancies and phases. Occupation number representation for equations of motion. Continuum media approximation and inapplicability of moment expansions. Long-range transitions vs percolation theory. Concentration expansion as a general constructive basis for analytical methods. Scaling properties of propagators. Singular point. Dynamical and kinematical memory in RWDS. Ways of regrouping of concentration expansions. CTRW and semi-phenomenology. Coherent medium approximation for nuclear relaxation via paramagnetic impurities. Combining of memory functions and cumulant expansions for calculation of FID. Path integral representations for RWDS. Numerical simulations of RWDS. Spin dynamics in magnetically diluted systems with low Zeeman and medium low dipole temperatures. Cluster expansions, regularization of dipole interactions and spectral dynamics.

  11. Theory of nuclear magnetic relaxation

    NASA Technical Reports Server (NTRS)

    Mcconnell, J.

    1983-01-01

    A theory of nuclear magnetic interaction is based on the study of the stochastic rotation operator. The theory is applied explicitly to relaxation by anisotropic chemical shift and to spin-rotational interactions. It is applicable also to dipole-dipole and quadrupole interactions.

  12. "Stressing" Relaxation in the Classroom.

    ERIC Educational Resources Information Center

    Prager-Decker, Iris

    A rationale is offered for incorporating relaxation training in elementary school classroom activities. Cited are research studies which focus on the reaction of children to stressful life changes and resulting behavioral and physical disorders. A list is given of significant life events which may be factors in causing diseases or misbehavior in…

  13. Relaxation times estimation in MRI

    NASA Astrophysics Data System (ADS)

    Baselice, Fabio; Caivano, Rocchina; Cammarota, Aldo; Ferraioli, Giampaolo; Pascazio, Vito

    2014-03-01

    Magnetic Resonance Imaging is a very powerful techniques for soft tissue diagnosis. At the present, the clinical evaluation is mainly conducted exploiting the amplitude of the recorded MR image which, in some specific cases, is modified by using contrast enhancements. Nevertheless, spin-lattice (T1) and spin-spin (T2) relaxation times can play an important role in many pathology diagnosis, such as cancer, Alzheimer or Parkinson diseases. Different algorithms for relaxation time estimation have been proposed in literature. In particular, the two most adopted approaches are based on Least Squares (LS) and on Maximum Likelihood (ML) techniques. As the amplitude noise is not zero mean, the first one produces a biased estimator, while the ML is unbiased but at the cost of high computational effort. Recently the attention has been focused on the estimation in the complex, instead of the amplitude, domain. The advantage of working with real and imaginary decomposition of the available data is mainly the possibility of achieving higher quality estimations. Moreover, the zero mean complex noise makes the Least Square estimation unbiased, achieving low computational times. First results of complex domain relaxation times estimation on real datasets are presented. In particular, a patient with an occipital lesion has been imaged on a 3.0T scanner. Globally, the evaluation of relaxation times allow us to establish a more precise topography of biologically active foci, also with respect to contrast enhanced images.

  14. Choosing a skeletal muscle relaxant.

    PubMed

    See, Sharon; Ginzburg, Regina

    2008-08-01

    Skeletal muscle relaxants are widely used in treating musculoskeletal conditions. However, evidence of their effectiveness consists mainly of studies with poor methodologic design. In addition, these drugs have not been proven to be superior to acetaminophen or nonsteroidal anti-inflammatory drugs for low back pain. Systematic reviews and meta-analyses support using skeletal muscle relaxants for short-term relief of acute low back pain when nonsteroidal anti-inflammatory drugs or acetaminophen are not effective or tolerated. Comparison studies have not shown one skeletal muscle relaxant to be superior to another. Cyclobenzaprine is the most heavily studied and has been shown to be effective for various musculoskeletal conditions. The sedative properties of tizanidine and cyclobenzaprine may benefit patients with insomnia caused by severe muscle spasms. Methocarbamol and metaxalone are less sedating, although effectiveness evidence is limited. Adverse effects, particularly dizziness and drowsiness, are consistently reported with all skeletal muscle relaxants. The potential adverse effects should be communicated clearly to the patient. Because of limited comparable effectiveness data, choice of agent should be based on side-effect profile, patient preference, abuse potential, and possible drug interactions. PMID:18711953

  15. Relaxation properties in classical diamagnetism

    NASA Astrophysics Data System (ADS)

    Carati, A.; Benfenati, F.; Galgani, L.

    2011-06-01

    It is an old result of Bohr that, according to classical statistical mechanics, at equilibrium a system of electrons in a static magnetic field presents no magnetization. Thus a magnetization can occur only in an out of equilibrium state, such as that produced through the Foucault currents when a magnetic field is switched on. It was suggested by Bohr that, after the establishment of such a nonequilibrium state, the system of electrons would quickly relax back to equilibrium. In the present paper, we study numerically the relaxation to equilibrium in a modified Bohr model, which is mathematically equivalent to a billiard with obstacles, immersed in a magnetic field that is adiabatically switched on. We show that it is not guaranteed that equilibrium is attained within the typical time scales of microscopic dynamics. Depending on the values of the parameters, one has a relaxation either to equilibrium or to a diamagnetic (presumably metastable) state. The analogy with the relaxation properties in the Fermi Pasta Ulam problem is also pointed out.

  16. Relaxed Linearized Algorithms for Faster X-Ray CT Image Reconstruction.

    PubMed

    Nien, Hung; Fessler, Jeffrey A

    2016-04-01

    Statistical image reconstruction (SIR) methods are studied extensively for X-ray computed tomography (CT) due to the potential of acquiring CT scans with reduced X-ray dose while maintaining image quality. However, the longer reconstruction time of SIR methods hinders their use in X-ray CT in practice. To accelerate statistical methods, many optimization techniques have been investigated. Over-relaxation is a common technique to speed up convergence of iterative algorithms. For instance, using a relaxation parameter that is close to two in alternating direction method of multipliers (ADMM) has been shown to speed up convergence significantly. This paper proposes a relaxed linearized augmented Lagrangian (AL) method that shows theoretical faster convergence rate with over-relaxation and applies the proposed relaxed linearized AL method to X-ray CT image reconstruction problems. Experimental results with both simulated and real CT scan data show that the proposed relaxed algorithm (with ordered-subsets [OS] acceleration) is about twice as fast as the existing unrelaxed fast algorithms, with negligible computation and memory overhead. PMID:26685227

  17. Dielectric relaxations in aliphatic polyesters

    NASA Astrophysics Data System (ADS)

    Sen, Sudeepto

    2001-07-01

    The dielectric technique was used to study the relaxation processes of five linear aliphatic polyesters. The polyesters studied were poly (ethylene succinate/adipate) or PESA, poly (trimethylene succinate/adipate) or PTSA, poly (butylene succinate/adipate) or PBSA, poly (ethylene succinate) or PES, and poly (ethylene adipate) or PEA. Three of the polyesters were copolymers (PESA, PTSA, and PBSA), and the remaining two (PES and PEA) were homopolymers. Two of the five were amorphous (PESA and PTSA), and the remaining three (PBSA, PES, and PEA) were semicrystalline. All the five polyesters were synthesized in the laboratory using a poly-condensation reaction between a series of aliphatic diols and diesters. The succinic and adipic groups in the copolymers are in equimolar amounts. The polymers were characterized by differential scanning calorimetry and density measurements. Elemental analysis done on the polymers confirmed that their compositions matched theoretical estimates. The relaxation processes were studied dielectrically using an IMASS time domain dielectric spectrometer (TDS) and an HP 4284A LCR meter. Together they allowed a frequency range from 0.001 Hz to 1 MHz. Typically in the subglass region, good data were obtained between 0.01 Hz and 100 kHz. In the glass transition region, good data were occasionally available over the entire range. Two relaxation processes were detected in the subglass temperature region for all the polymers, and in the case of the copolymers PTSA and PBSA, they were also well resolved. Both the processes showed Arrhenius behavior with modest activation energies characteristic of subglass processes in general. They also progressively merged with increasing temperature, which implies a lower activation energy for the faster process which is consistent with the current understanding of relaxation phenomena. The glass transition region of all the polymers also showed a merging of the dominant alpha relaxation with the subglass

  18. Augmented reality: past, present, future

    NASA Astrophysics Data System (ADS)

    Inzerillo, Laura

    2013-03-01

    A great opportunity has permitted to carry out a cultural, historical, architectural and social research with great impact factor on the international cultural interest. We are talking about the realization of a museum whose the main theme is the visit and the discovery of a monument of great prestige: the monumental building the "Steri" in Palermo. The museum is divided into sub themes including the one above all, that has aroused the international interest so much that it has been presented the instance to include the museum in the cultural heritage of UNESCO. It is the realization of a museum path that regards the cells of the Inquisition, which are located just inside of some buildings of the monumental building. The project, as a whole, is faced, in a total view, between the various competences implicated: historic, chemic, architectonic, topographic, drawing, representation, virtual communication, informatics. The birth of the museum will be a sum of the results of all these disciplines involved. Methodology, implementation, fruition, virtual museum, goals, 2D graphic restitution, effects on the cultural heritage and landscape environmental, augmented reality, Surveying 2D and 3D, hi-touch screen, Photogrammetric survey, Photographic survey, representation, drawing 3D and more than this has been dealt with this research.

  19. Wireless Augmented Reality Prototype (WARP)

    NASA Technical Reports Server (NTRS)

    Devereaux, A. S.

    1999-01-01

    Initiated in January, 1997, under NASA's Office of Life and Microgravity Sciences and Applications, the Wireless Augmented Reality Prototype (WARP) is a means to leverage recent advances in communications, displays, imaging sensors, biosensors, voice recognition and microelectronics to develop a hands-free, tetherless system capable of real-time personal display and control of computer system resources. Using WARP, an astronaut may efficiently operate and monitor any computer-controllable activity inside or outside the vehicle or station. The WARP concept is a lightweight, unobtrusive heads-up display with a wireless wearable control unit. Connectivity to the external system is achieved through a high-rate radio link from the WARP personal unit to a base station unit installed into any system PC. The radio link has been specially engineered to operate within the high- interference, high-multipath environment of a space shuttle or space station module. Through this virtual terminal, the astronaut will be able to view and manipulate imagery, text or video, using voice commands to control the terminal operations. WARP's hands-free access to computer-based instruction texts, diagrams and checklists replaces juggling manuals and clipboards, and tetherless computer system access allows free motion throughout a cabin while monitoring and operating equipment.

  20. Augmented reality in surgical procedures

    NASA Astrophysics Data System (ADS)

    Samset, E.; Schmalstieg, D.; Vander Sloten, J.; Freudenthal, A.; Declerck, J.; Casciaro, S.; Rideng, Ø.; Gersak, B.

    2008-02-01

    Minimally invasive therapy (MIT) is one of the most important trends in modern medicine. It includes a wide range of therapies in videoscopic surgery and interventional radiology and is performed through small incisions. It reduces hospital stay-time by allowing faster recovery and offers substantially improved cost-effectiveness for the hospital and the society. However, the introduction of MIT has also led to new problems. The manipulation of structures within the body through small incisions reduces dexterity and tactile feedback. It requires a different approach than conventional surgical procedures, since eye-hand co-ordination is not based on direct vision, but more predominantly on image guidance via endoscopes or radiological imaging modalities. ARIS*ER is a multidisciplinary consortium developing a new generation of decision support tools for MIT by augmenting visual and sensorial feedback. We will present tools based on novel concepts in visualization, robotics and haptics providing tailored solutions for a range of clinical applications. Examples from radio-frequency ablation of liver-tumors, laparoscopic liver surgery and minimally invasive cardiac surgery will be presented. Demonstrators were developed with the aim to provide a seamless workflow for the clinical user conducting image-guided therapy.

  1. Postauricular fascia in augmentation rhinoplasty.

    PubMed

    Guerra, Aldo Benjamin

    2014-06-01

    Ten rhinoplasty operations performed using postauricular fascia for the purpose of augmenting the radix and dorsum of the nose were analyzed retrospectively. All the operations were performed over a 1-year period, between 2005 and 2006. The fascia of the postauricular area has been used as a source of pliable soft-tissue grafts in primary and revision rhinoplasty. It may be easily accessed using a single sulcus incision that also enables harvesting of ear cartilage grafts. Deficiency in the radix is an overlooked abnormality seen in many patients undergoing primary as well as revision rhinoplasty after aggressive hump removal. Recent trends in rhinoplasty have been to avoid the overly reduced nasal skeleton and to create a more balanced nasal surgery result. This article presents the use of the postauricular fascia as a radix graft that has been found to be simple to carry out, reliable, and long lasting. In addition, the fascia graft is useful in the camouflage of various nasal deformities in the dorsum and sidewalls. The average patient follow-up for the study was 24 months. PMID:24932819

  2. Augmented reality for wafer prober

    NASA Astrophysics Data System (ADS)

    Gilgenkrantz, Pascal

    2011-03-01

    The link between wafer manufacturing and wafer test is often weak: without common information system, Test engineers have to read locations of test structures from reference documents and search them on the wafer prober screen. Mask Data Preparation team is ideally placed to fill this gap, given its relationship with both design and manufacturing sides. With appropriate design extraction scripts and design conventions, mask engineers can provide exact wafer locations of all embedded test structures to avoid a painful camera search. Going a step further, it would be a great help to provide to wafer probers a "map" of what was build on wafers. With this idea in mind, mask design database can simply be provided to Test engineers; but the real added value would come from a true integration of real-wafer camera views and design database used for wafer manufacturing. As proven by several augmented reality applications, like Google Maps' mixed Satellite/Map view, mixing a real-world view with its theoretical model is very useful to understand the reality. The creation of such interface can only be made by a wafer prober manufacturer, given the high integration of these machines with their control panel. But many existing software libraries could be used to plot the design view matching the camera view. Standard formats for mask design are usually GDSII and OASIS (SEMI P39 standard); multiple free software and commercial viewers/editors/libraries for these formats are available.

  3. Equivalent Relaxations of Optimal Power Flow

    SciTech Connect

    Bose, S; Low, SH; Teeraratkul, T; Hassibi, B

    2015-03-01

    Several convex relaxations of the optimal power flow (OPF) problem have recently been developed using both bus injection models and branch flow models. In this paper, we prove relations among three convex relaxations: a semidefinite relaxation that computes a full matrix, a chordal relaxation based on a chordal extension of the network graph, and a second-order cone relaxation that computes the smallest partial matrix. We prove a bijection between the feasible sets of the OPF in the bus injection model and the branch flow model, establishing the equivalence of these two models and their second-order cone relaxations. Our results imply that, for radial networks, all these relaxations are equivalent and one should always solve the second-order cone relaxation. For mesh networks, the semidefinite relaxation and the chordal relaxation are equally tight and both are strictly tighter than the second-order cone relaxation. Therefore, for mesh networks, one should either solve the chordal relaxation or the SOCP relaxation, trading off tightness and the required computational effort. Simulations are used to illustrate these results.

  4. Augmented railgun using a permanent magnet

    SciTech Connect

    Katsuki, S.; Akiyama, H.; Eguchi, N.; Sueda, T.; Soejima, M.; Maeda, S.; Sato, K.N.

    1995-08-01

    The use of a permanent magnet instead of an electromagnet has been proposed for the augmentation of the magnetic field of a railgun driven by a current of approximately 20 kA. A permanent magnet has the following advantages in comparison with conventional augmentations using additional turns: (1) simple configuration of the system, (2) temporally and spatially constant magnetic fields, and (3) high efficiency. Here, the operation of a conventional railgun and that of an augmented railgun using a permanent magnet are compared experimentally, and the usefulness of the permanent magnet is described. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  5. [Complications of breast augmentation - a case report].

    PubMed

    Zedníková, I; Třešková, I; Schmiedhuber, P; Hes, O

    2012-08-01

    As with any surgery, breast augmentation does have certain risks and complications. The aim of this article is to point out a rare complication of breast augmentation - axillary silicone lymphadenopathy (defined as the presence of silicone in the lymph nodes). The authors present a case report of silicone lymphadenopathy in a young woman after the rupture of a silicone breast implant. As the number of women with breast implants is increasing, it is necessary to bear this rare complication of breast augmentation in mind in differential diagnosis of axillary lymphadenopathy. PMID:23153428

  6. Demonstration of relaxed static stability on a commercial transport

    NASA Technical Reports Server (NTRS)

    Rising, J. J.; Davis, W. J.; Willey, C. S.; Cokeley, R. C.

    1984-01-01

    Increasing jet aircraft fuel costs from 25 percent to nearly 60 percent of the aircraft direct operating costs have led to a heavy emphasis on the development of transport aircraft with significantly improved aerodynamic performance. The application of the concept of relaxed static stability (RSS) and the utilization of an active control stability augmentation system make it possible to design an aircraft with reduced aerodynamic trim drag due to a farther-aft cg balance. Reduced aerodynamic parasite drag and lower structural weight due to a smaller horizontal tail surface can also be obtained. The application of RSS has been studied under a NASA-sponsored program to determine ways of improving the energy efficiency in current and future transport aircraft. Attention is given to a near-term pitch active control system, an advanced pitch active control system, and an operational overview.

  7. Plasmon-mediated energy relaxation in graphene

    NASA Astrophysics Data System (ADS)

    Ferry, D. K.; Somphonsane, R.; Ramamoorthy, H.; Bird, J. P.

    2015-12-01

    Energy relaxation of hot carriers in graphene is studied at low temperatures, where the loss rate may differ significantly from that predicted for electron-phonon interactions. We show here that plasmons, important in the relaxation of energetic carriers in bulk semiconductors, can also provide a pathway for energy relaxation in transport experiments in graphene. We obtain a total loss rate to plasmons that results in energy relaxation times whose dependence on temperature and density closely matches that found experimentally.

  8. Plasmon-mediated energy relaxation in graphene

    SciTech Connect

    Ferry, D. K.; Somphonsane, R.; Ramamoorthy, H.; Bird, J. P.

    2015-12-28

    Energy relaxation of hot carriers in graphene is studied at low temperatures, where the loss rate may differ significantly from that predicted for electron-phonon interactions. We show here that plasmons, important in the relaxation of energetic carriers in bulk semiconductors, can also provide a pathway for energy relaxation in transport experiments in graphene. We obtain a total loss rate to plasmons that results in energy relaxation times whose dependence on temperature and density closely matches that found experimentally.

  9. Viscoelastic Relaxation of Lunar Basins

    NASA Astrophysics Data System (ADS)

    Mohit, P. S.; Phillips, R. J.

    2004-12-01

    The large lunar impact basins provide a unique glimpse into early lunar history. Here we investigate the possibility that the relief of the oldest lunar basins (with the exception of South-Pole Aitken) has decayed through viscous relaxation. We identify nine ancient multi-ring basins with very low relief and low-amplitude Bouguer and free-air gravity anomalies. The characteristics of these basins are consistent with either 1) relaxation of topographic relief by ductile flow (e.g. Solomon et al., 1982) or 2) obliteration of basin topography during crater collapse immediately following impact. Both scenarios require that the basins formed early in lunar history, when the Moon was hot. The latter possibility appears to be unlikely due to the great topographic relief of South Pole-Aitken basin (SPA), the largest and oldest impact basin on the Moon (with the possible exception of the putative Procellarum basin; Wilhelms, 1987). On the other hand, the thin crust beneath SPA may not have allowed ductile flow in its lower portions, even for a hot Moon, implying that a thicker crust is required beneath other ancient basins for the hypothesis of viscous relaxation to be tenable. Using a semi-analytic, self-gravitating viscoelastic model, we investigate the conditions necessary to produce viscous relaxation of lunar basins. We model topographic relaxation for a crustal thickness of 30 km, using a dry diabase flow law for the crust and dry olivine for the mantle. We find that the minimum temperature at the base of the crust (Tb) permitting nearly complete relaxation of topography by ductile flow on a timescale < 108 yrs is 1400 K, corresponding to a heat flow of 55mW/m2, into the crust. Ductile flow in the lower crust becomes increasingly difficult as the crustal thickness decreases. The crust beneath SPA, thinned by the impact, is only 15-20 km thick and would require Tb ≥ 1550 K for relaxation to occur. The fact that SPA has maintained high-amplitude relief suggests that

  10. Kinetic activation-relaxation technique.

    PubMed

    Béland, Laurent Karim; Brommer, Peter; El-Mellouhi, Fedwa; Joly, Jean-François; Mousseau, Normand

    2011-10-01

    We present a detailed description of the kinetic activation-relaxation technique (k-ART), an off-lattice, self-learning kinetic Monte Carlo (KMC) algorithm with on-the-fly event search. Combining a topological classification for local environments and event generation with ART nouveau, an efficient unbiased sampling method for finding transition states, k-ART can be applied to complex materials with atoms in off-lattice positions or with elastic deformations that cannot be handled with standard KMC approaches. In addition to presenting the various elements of the algorithm, we demonstrate the general character of k-ART by applying the algorithm to three challenging systems: self-defect annihilation in c-Si (crystalline silicon), self-interstitial diffusion in Fe, and structural relaxation in a-Si (amorphous silicon). PMID:22181304

  11. Models of violently relaxed galaxies

    NASA Astrophysics Data System (ADS)

    Merritt, David; Tremaine, Scott; Johnstone, Doug

    1989-02-01

    The properties of spherical self-gravitating models derived from two distribution functions that incorporate, in a crude way, the physics of violent relaxation are investigated. The first distribution function is identical to the one discussed by Stiavelli and Bertin (1985) except for a change in the sign of the 'temperature', i.e., e exp(-aE) to e exp(+aE). It is shown that these 'negative temperature' models provide a much better description of the end-state of violent relaxation than 'positive temperature' models. The second distribution function is similar to the first except for a different dependence on angular momentum. Both distribution functions yield single-parameter families of models with surface density profiles very similar to the R exp 1/4 law. Furthermore, the central concentration of models in both families increases monotonically with the velocity anisotropy, as expected in systems that formed through cold collapse.

  12. Muzzle shunt augmentation of conventional railguns

    SciTech Connect

    Parker, J.V. . Physics Div.)

    1991-01-01

    This paper reports on augmentation which is a technique for reducing the armature current and hence the armature power dissipation in a plasma armature railgun. In spite of the advantages, no large augmented railguns have been built, primarily due to the mechanical and electrical complexity introduced by the extra conductors required. it is possible to achieve some of the benefits of augmentation in a conventional railgun by diverting a fraction {phi} of the input current through a shunt path at the muzzle of the railgun. In particular, the relation between force and armature current is the same as that obtained in an n-turn, series-connected augmented railgun with n = 1/(1 {minus} {phi}). The price of this simplification is a reduction in electrical efficiency and some additional complexity in the external electrical system.

  13. Augmented Reality Simulations on Handheld Computers

    ERIC Educational Resources Information Center

    Squire, Kurt; Klopfer, Eric

    2007-01-01

    Advancements in handheld computing, particularly its portability, social interactivity, context sensitivity, connectivity, and individuality, open new opportunities for immersive learning environments. This article articulates the pedagogical potential of augmented reality simulations in environmental engineering education by immersing students in…

  14. Improved diffuser for augmenting a wind turbine

    DOEpatents

    Foreman, K.M.; Gilbert, B.L.

    A diffuser for augmenting a wind turbine having means for energizing the boundary layer at several locations along the diffuser walls is improved by the addition of a short collar extending radially outward from the outlet of the diffuser.

  15. A parametric evaluation of railgun augmentation

    NASA Astrophysics Data System (ADS)

    Kotas, J. F.; Guderjahn, C. A.; Littman, F. D.

    1986-11-01

    A general dynamic system model of an augmented electromagnetic launch (EML) system was developed. This model was used to characterize the augmentation effect on EML system performance by a direct comparison to a nonaugmented or simple railgun system. The results of these calculations indicate that increasing rail augmentation increases both Joule heating losses and total EML system inductance. These losses and the larger system inductance were shown to decrease system efficiency despite the lower peak rail current required to induce the same Lorentz force on the projectile in the simple EML system. The Joule heating loss was shown to be reduced by decreasing the initial augmentor rail temperature or by increasing the augmentor rail area. This paper discusses the augmented EML system model and reports the results of the parametric calculations.

  16. The ELF-I augmented electromagnetic launcher

    NASA Astrophysics Data System (ADS)

    Fikse, D. A.; Wu, J. L.; Thio, Y. C.

    1984-03-01

    Augmenting an electromagnetic launcher barrel with one or more turns can theoretically increase the launcher system performance more than twice that of a simple EML. This is accomplished by increasing the amount of magnetic flux in the bore and thus increasing the electromagnetic accelerating force. The potential for augmented barrels had yet to be evaluated, therefore a one meter long test barrel was designed and constructed. This barrel was tested in the ELF-I electromagnetic test facility and the results compared with the theoretically predicted performance of a simple barrel design. This comparison shows an increase in muzzle velocity of 83 percent for the augmented case over the simple launcher case. It was also found that the augmented barrel could be fabricated in a simple manner within the physical limitations of a conventional barrel size, and that its solid armatures provided an excellent method of achieving longer rail life, averaging 20 shots per rail set.

  17. Diffuser for augmenting a wind turbine

    DOEpatents

    Foreman, Kenneth M.; Gilbert, Barry L.

    1984-01-01

    A diffuser for augmenting a wind turbine having means for energizing the boundary layer at several locations along the diffuser walls is improved by the addition of a short collar extending radially outward from the outlet of the diffuser.

  18. Shear Relaxations of Confined Liquids.

    NASA Astrophysics Data System (ADS)

    Carson, George Amos, Jr.

    Ultrathin (<40 A) films of octamethylcyclotetrasiloxane (OMCTS), hexadecane, and dodecane were subjected to linear and non-linear oscillatory shear between flat plates. Shearing frequencies of 0.1 to 800 s^{-1} were applied at pressures from zero to 0.8 MPa using a surface rheometer only recently developed. In most cases the plates were atomically smooth mica surfaces; the role of surface interactions was examined by replacing these with alkyl chain monolayers. OMCTS and hexadecane were examined at a temperature about 5 Celsius degrees above their melting points and tended to solidify. Newtonian plateaus having enormous viscosities were observed at low shear rates. The onset of shear thinning implied relaxation times of about 0.1 s in the linear structure of the confined liquids. Large activation volumes (~80 nm ^3) suggested that shear involved large-scale collective motion. Dodecane was studied at a much higher temperature relative to its melting point and showed no signs of impending solidification though it exhibited well-defined regions of Newtonian response and power law shear thinning. When treated with molecular sieves before use, dodecane had relaxation times which were short (0.02 s) compared to hexadecane, but still exhibited large-scale collective motion. When treated with silica gel, an unexplained long -time relaxation (10 s) was seen in the Newtonian viscosity of dodecane. The relaxation time of the linear structure, 0.005 s was very small, and the storage modulus was unresolvable. The small activation volume (7nm^3) indicated a much lower level of collective motion. The activation volume remained small when dodecane was confined between tightly bound, low energy, alkyl monolayers. At low strains the storage and loss moduli became very large (>10^4 Pa), probably due to interactions with flaws in the monolayers. Dramatic signs of wall slip were observed at large strains even at low pressures.

  19. Dynamic Relaxation of Financial Indices

    NASA Astrophysics Data System (ADS)

    Shen, J.; Zheng, B.; Lin, H.; Qiu, T.

    The dynamic relaxation of the German DAX both before and after a large price-change is investigated. The dynamic behavior is characterized by a power law. At the minutely time scale, the exponent p governing the power-law behavior takes a same value before and after the large price change, while at the daily time scale, it is different. Numerical simulations of an interacting EZ herding model are performed for comparison.

  20. Shear relaxations of confined liquids

    SciTech Connect

    Carson, G.A. Jr.

    1992-01-01

    Ultrathin (<40 [angstrom]) films of octamethylcyclotetrasiloxane (OMCTS), hexadecane, and dodecane were subjected to linear and non-linear oscillatory shear between flat plates. Shearing frequencies of 0.1 to 800 s[sup [minus]1] were applied at pressures from zero to 0.8 MPa using a surface rheometer only recently developed. In most cases the plates were atomically smooth mica surfaces; the role of surface interactions was examined by replacing these with alkyl chain monolayers. OMCTS and hexadecane were examined at a temperature about 5 Celcius degrees above their melting points and tended to solidify. Newtonian plateaus having enormous viscosities were observed at low shear rates. The onset of shear thinning implied relaxation times of about 0.1 s in the linear structure of the confined liquids. Large activation volumes ([approximately]80 nm[sup 3]) suggested that shear involved large-scale collective motion. Dodecane was studied at a much higher temperature relative to its melting point and showed no signs of impending solidification though it exhibited well-defined regions of Newtonian response and power law shear thinning. When treated with molecular sieves before use, dodecane had relaxation times which were short (0.02 s) compared to hexadecane, but still exhibited large-scale collective motion. When treated with silica gel, an unexplained long-time relaxation (10 s) was seen in the Newtonian viscosity of dodecane. The relaxation time of the linear structure, 0.005 s was very small, and the storage modulus was unresolvable. The small activation volume (7 nm[sup 3]) indicated a much lower level of collective motion. The activation volume remained small when dodecane was confined between tightly bound, low energy, alkyl monolayers. At low strains the storage and loss moduli became very large (>10[sup 4] Pa), probably due to interactions with flaws in the monolayers. Dramatic signs of wall slip were observed at large strains even at low pressures.

  1. Relaxation: A Fourth "R" for Education.

    ERIC Educational Resources Information Center

    Frederick, A. B.

    Relaxation training helps the individual handle tension through concentrating upon efficient use of muscles. A program of progressive relaxation can be easily incorporated into elementary and secondary schools. Objectives of such a program include the following: (a) to learn to relax technically for purposes of complete rest (deep muscle…

  2. Satisfying patient expectations with poly-L-lactic acid soft tissue augmentation.

    PubMed

    Vleggaar, Danny; Fitzgerald, Rebecca; Lorenc, Z Paul

    2014-04-01

    Patient interest and physician use of soft tissue augmentation have increased significantly in recent years, especially among younger patients. A recent consumer survey conducted on behalf of the American Society of Plastic Surgeons found that the majority of respondents would rather have a facial injectable treatment than a surgical treatment. In another recent survey, consumers gave the highest overall satisfaction ratings to injectable filler treatments (92%), including poly-L-lactic acid (PLLA), and injectable wrinkle relaxers (92%), with injectable fillers receiving the highest "extremely satisfied" rating (45%). Long-lasting benefit is a desirable attribute in soft tissue augmentation, making PLLA a favorable alternative for many patients. When considering the use of PLLA, clinicians should ensure that their patients understand its benefit profile, and that these benefits are consistent with the patients' cosmetic goals. The implementation of the latest recommendations on methodological approaches in the use of PLLA will minimize the occurrence of adverse events, further enhancing patient satisfaction. PMID:24719077

  3. Arresting relaxation in Pickering Emulsions

    NASA Astrophysics Data System (ADS)

    Atherton, Tim; Burke, Chris

    2015-03-01

    Pickering emulsions consist of droplets of one fluid dispersed in a host fluid and stabilized by colloidal particles absorbed at the fluid-fluid interface. Everyday materials such as crude oil and food products like salad dressing are examples of these materials. Particles can stabilize non spherical droplet shapes in these emulsions through the following sequence: first, an isolated droplet is deformed, e.g. by an electric field, increasing the surface area above the equilibrium value; additional particles are then adsorbed to the interface reducing the surface tension. The droplet is then allowed to relax toward a sphere. If more particles were adsorbed than can be accommodated by the surface area of the spherical ground state, relaxation of the droplet is arrested at some non-spherical shape. Because the energetic cost of removing adsorbed colloids exceeds the interfacial driving force, these configurations can remain stable over long timescales. In this presentation, we present a computational study of the ordering present in anisotropic droplets produced through the mechanism of arrested relaxation and discuss the interplay between the geometry of the droplet, the dynamical process that produced it, and the structure of the defects observed.

  4. Spin relaxation in metallic ferromagnets

    NASA Astrophysics Data System (ADS)

    Berger, L.

    2011-02-01

    The Elliott theory of spin relaxation in metals and semiconductors is extended to metallic ferromagnets. Our treatment is based on the two-current model of Fert, Campbell, and Jaoul. The d→s electron-scattering process involved in spin relaxation is the inverse of the s→d process responsible for the anisotropic magnetoresistance (AMR). As a result, spin-relaxation rate 1/τsr and AMR Δρ are given by similar formulas, and are in a constant ratio if scattering is by solute atoms. Our treatment applies to nickel- and cobalt-based alloys which do not have spin-up 3d states at the Fermi level. This category includes many of the technologically important magnetic materials. And we show how to modify the theory to apply it to bcc iron-based alloys. We also treat the case of Permalloy Ni80Fe20 at finite temperature or in thin-film form, where several kinds of scatterers exist. Predicted values of 1/τsr and Δρ are plotted versus resistivity of the sample. These predictions are compared to values of 1/τsr and Δρ derived from ferromagnetic-resonance and AMR experiments in Permalloy.

  5. Breast augmentation with an unknown substance

    PubMed Central

    Ebrahim, Lamya; Morrison, David; Kop, Alan; Taylor, Donna

    2014-01-01

    Before the widespread use of silicone implants various foreign substances were injected directly into the breasts. The nature of these materials sometimes remains unknown and can cause various complications requiring surgical intervention. Preoperative diagnostic imaging can help characterise the type and distribution of the injected material, thereby assisting in making decisions regarding treatment. We report a case of breast augmentation with an unknown substance, aiming to highlight some imaging characteristics of different breast augmentation substances. PMID:24957586

  6. Muzzle shunt augmentation of conventional railguns

    SciTech Connect

    Parker, J.V.

    1990-01-01

    Augmentation is a well-known technique for reducing the armature current and hence the armature power dissipation in a plasma armature railgun. In spite of the advantages, no large augmented railguns have been built, primarily due to the mechanical and electrical complexity introduce by the extra conductors required. It is possible to achieve some of the benefits of augmentation in conventional railgun by diverting a fraction {phi} of the input current through a shunt path at the muzzle of the railgun. In particular, the relation between force and armature current is the same as that obtained in an n-turn, series connected augmented railgun with n = 1/(1-{phi}). The price of this simplification is a reduction in electrical efficiency and some additional complexity in the external electrical system. Additions to the electrical system are required to establish the shunt current and to control its magnitude during projectile acceleration. The relationship between muzzle shunt augmentation and conventional series augmentation is developed and various techniques is developed and various techniques for establishing and controlling the shunt current are illustrated with a practical example. 5 refs., 8 figs., 2 tabs.

  7. Effects of Progressive Relaxation versus Biofeedback-Assisted Relaxation with College Students.

    ERIC Educational Resources Information Center

    See, John D.; Czerlinsky, Thomas

    1990-01-01

    Examined use of biofeedback, relaxation training, or both in a college relaxation class with an enrollment of 33 students. Results indicated students receiving relaxation training plus biofeedback improved significantly more on psychological variables than did students receiving only relaxation training. (Author/ABL)

  8. Relation between Direct Observation of Relaxation and Self-Reported Mindfulness and Relaxation States

    ERIC Educational Resources Information Center

    Hites, Lacey S.; Lundervold, Duane A.

    2013-01-01

    Forty-four individuals, 18-47 (MN 21.8, SD 5.63) years of age, took part in a study examining the magnitude and direction of the relationship between self-report and direct observation measures of relaxation and mindfulness. The Behavioral Relaxation Scale (BRS), a valid direct observation measure of relaxation, was used to assess relaxed behavior…

  9. Augmenting digital displays with computation

    NASA Astrophysics Data System (ADS)

    Liu, Jing

    As we inevitably step deeper and deeper into a world connected via the Internet, more and more information will be exchanged digitally. Displays are the interface between digital information and each individual. Naturally, one fundamental goal of displays is to reproduce information as realistically as possible since humans still care a lot about what happens in the real world. Human eyes are the receiving end of such information exchange; therefore it is impossible to study displays without studying the human visual system. In fact, the design of displays is rather closely coupled with what human eyes are capable of perceiving. For example, we are less interested in building displays that emit light in the invisible spectrum. This dissertation explores how we can augment displays with computation, which takes both display hardware and the human visual system into consideration. Four novel projects on display technologies are included in this dissertation: First, we propose a software-based approach to driving multiview autostereoscopic displays. Our display algorithm can dynamically assign views to hardware display zones based on multiple observers' current head positions, substantially reducing crosstalk and stereo inversion. Second, we present a dense projector array that creates a seamless 3D viewing experience for multiple viewers. We smoothly interpolate the set of viewer heights and distances on a per-vertex basis across the arrays field of view, reducing image distortion, crosstalk, and artifacts from tracking errors. Third, we propose a method for high dynamic range display calibration that takes into account the variation of the chrominance error over luminance. We propose a data structure for enabling efficient representation and querying of the calibration function, which also allows user-guided balancing between memory consumption and the amount of computation. Fourth, we present user studies that demonstrate that the ˜ 60 Hz critical flicker fusion

  10. Dynamics of Glass Relaxation at Room Temperature

    NASA Astrophysics Data System (ADS)

    Welch, Roger C.; Smith, John R.; Potuzak, Marcel; Guo, Xiaoju; Bowden, Bradley F.; Kiczenski, T. J.; Allan, Douglas C.; King, Ellyn A.; Ellison, Adam J.; Mauro, John C.

    2013-06-01

    The problem of glass relaxation under ambient conditions has intrigued scientists and the general public for centuries, most notably in the legend of flowing cathedral glass windows. Here we report quantitative measurement of glass relaxation at room temperature. We find that Corning® Gorilla® Glass shows measurable and reproducible relaxation at room temperature. Remarkably, this relaxation follows a stretched exponential decay rather than simple exponential relaxation, and the value of the stretching exponent (β=3/7) follows a theoretical prediction made by Phillips for homogeneous glasses.

  11. Time of relaxation in dusty plasma model

    NASA Astrophysics Data System (ADS)

    Timofeev, A. V.

    2015-11-01

    Dust particles in plasma may have different values of average kinetic energy for vertical and horizontal motion. The partial equilibrium of the subsystems and the relaxation processes leading to this asymmetry are under consideration. A method for the relaxation time estimation in nonideal dusty plasma is suggested. The characteristic relaxation times of vertical and horizontal motion of dust particles in gas discharge are estimated by analytical approach and by analysis of simulation results. These relaxation times for vertical and horizontal subsystems appear to be different. A single hierarchy of relaxation times is proposed.

  12. Model for relaxation oscillations in a helicon discharge

    NASA Astrophysics Data System (ADS)

    Degeling, A. W.; Sheridan, T. E.; Boswell, R. W.

    1999-05-01

    Relaxation oscillations observed in the large-volume, helicon plasma experiment WOMBAT (Waves on Magnetized Beams and Turbulence) [R. W. Boswell and R. K. Porteous, Appl. Phys. Lett. 50, 1130 (1987)] are modeled. These oscillations have a period of several milliseconds and have been identified as transitions between a low-density, inductive discharge and a high-density, helicon-wave discharge. In the model, it is assumed that the mode transitions are triggered by variations in the neutral density in the source region. The neutral density decreases due to ionization augmented by ion pumping and increases due to refilling of the source chamber from the much larger diffusion chamber. The system is modeled using two, coupled, nonlinear, ordinary differential equations that describe the neutral and plasma densities in the source chamber. Ionization by inductively-coupled fields and ionization due to electrons accelerated by helicon waves with phase velocities near the threshold electron velocity for ionization are considered. The model is found to reproduce experimentally measured variations of the plasma density and helicon wave phase velocity with rf power, neutral pressure and magnetic field. The negative impedance needed for the existence of a relaxation oscillation is provided by the helicon-wave coupling mechanism.

  13. Hydrogen peroxide induced relaxation in porcine pulmonary arteries in vitro is mediated by EDRF and cyclic GMP

    SciTech Connect

    Zellers, T.; McCormick, J. )

    1991-03-15

    Xanthine and xanthine oxidase induced relaxations in porcine pulmonary arteries in vitro are augmented in the presence of the endothelium and abolished by catalase, implicating hydrogen peroxide as an endothelium-dependent effector. To determine the mechanism whereby H{sub 2}O{sub 2} causes relaxations, isolated rings of fifth order porcine pulmonary artery, with (E{sup +}) and without (E{sup {minus}}) endothelium, were suspended in organ baths filled with buffer, and isometric tension was recorded. Hydrogen peroxide caused concentration-dependent, endothelium-augmented relaxations which were abolished by catalase and hydroquinone and reversed by L-nitroarginine and methylene blue. Prostacyclin (PGI{sub 2}) levels, measured after a two minute exposure to H{sub 2}O{sub 2} in rings with endothelium were comparable to controls. This concentration of PGI{sub 2} does not cause relaxations in these rings. These data suggest that H{sub 2}O{sub 2} stimulates the release of an EDRF, causing relaxations mediated by cyclic GMP, which is independent of prostacyclin.

  14. Unusual fast secondary relaxation in metallic glass

    PubMed Central

    Wang, Q.; Zhang, S.T.; Yang, Y.; Dong, Y.D.; Liu, C.T.; Lu, J.

    2015-01-01

    The relaxation spectrum of glassy solids has long been used to probe their dynamic structural features and the fundamental deformation mechanisms. Structurally complicated glasses, such as molecular glasses, often exhibit multiple relaxation processes. By comparison, metallic glasses have a simple atomic structure with dense atomic packing, and their relaxation spectra were commonly found to be simpler than those of molecular glasses. Here we show the compelling evidence obtained across a wide range of temperatures and frequencies from a La-based metallic glass, which clearly shows two peaks of secondary relaxations (fast versus slow) in addition to the primary relaxation peak. The discovery of the unusual fast secondary relaxation unveils the complicated relaxation dynamics in metallic glasses and, more importantly, provides us the clues which help decode the structural features serving as the ‘trigger' of inelasticity on mechanical agitations. PMID:26204999

  15. Relaxation phenomenon in composite materials

    NASA Astrophysics Data System (ADS)

    Moznine, R. El.; Blanc, F.; Lieutier, M.; Lefort, A.

    1998-08-01

    Dielectric measurement characteristics such as the dissipation factor, relative permittivity and conductivity as a function of temperature and frequency have been achieved on composite materials based on different epoxy resins filled with alumina inclusions. The analysis of the results show the presence of porosity and inhomogeneity in these materials. The study of the dissipation factor, as a function of temperature at high frequencies, has shown an unexpected absorption phenomenon in materials designed to be utilized as electrical insulators. The identification of the entities responsible for this relaxation shows that the entities result from one of the components of the material. These results can also confirm the inhomogeneity of the materials.

  16. Image compression using constrained relaxation

    NASA Astrophysics Data System (ADS)

    He, Zhihai

    2007-01-01

    In this work, we develop a new data representation framework, called constrained relaxation for image compression. Our basic observation is that an image is not a random 2-D array of pixels. They have to satisfy a set of imaging constraints so as to form a natural image. Therefore, one of the major tasks in image representation and coding is to efficiently encode these imaging constraints. The proposed data representation and image compression method not only achieves more efficient data compression than the state-of-the-art H.264 Intra frame coding, but also provides much more resilience to wireless transmission errors with an internal error-correction capability.

  17. ARSC: Augmented Reality Student Card--An Augmented Reality Solution for the Education Field

    ERIC Educational Resources Information Center

    El Sayed, Neven A. M.; Zayed, Hala H.; Sharawy, Mohamed I.

    2011-01-01

    Augmented Reality (AR) is the technology of adding virtual objects to real scenes through enabling the addition of missing information in real life. As the lack of resources is a problem that can be solved through AR, this paper presents and explains the usage of AR technology we introduce Augmented Reality Student Card (ARSC) as an application of…

  18. Augmented Reality for the Improvement of Remote Laboratories: An Augmented Remote Laboratory

    ERIC Educational Resources Information Center

    Andujar, J. M.; Mejias, A.; Marquez, M. A.

    2011-01-01

    Augmented reality (AR) provides huge opportunities for online teaching in science and engineering, as these disciplines place emphasis on practical training and unsuited to completely nonclassroom training. This paper proposes a new concept in virtual and remote laboratories: the augmented remote laboratory (ARL). ARL is being tested in the first…

  19. Key technologies of outdoor augmented reality GIS

    NASA Astrophysics Data System (ADS)

    Ren, Fu; Du, Qingyun; Wu, Xueling

    2008-12-01

    Augmented Reality (AR) is a growing research area in virtual reality and generates a composite view for the user. It is combination of the real scene viewed by the user and a virtual scene generated by the computer that augments the scene with additional information. About 80 percent information in the real world is related with spatial location. The combination of Geographical information system (GIS) and AR technologies would promote the development of outdoor AR systems, and also would explore a new research direction for GIS. The key technologies of outdoor augmented reality GIS, including basic tracking methods, display devices, typical applications and registration processes, are discussed. In indoor augmented reality's closed environments the tracking of position and head orientation as well as the presentation of information is much more unproblematic than the same task in an outdoor environment. The main application task of outdoor augmented reality GIS is the presentation of information to a user while moving through an unknown region. The system helps to detect automatically objects in sight of a person who need its information. It compares the conventional solutions of 3D registration with, while it discusses their algorithm procedure to basic parameters to give out their advantages and disadvantages at different condition. While affine transformation approach uses the idea of computer graphics and vision technology for reference. Its accuracy is mainly based on the precision and speed of scene feature point extracted from natural or artificial feature.

  20. The transareolar incision for breast augmentation revisited.

    PubMed

    Kompatscher, Peter; Schuler, Christine; Beer, Gertrude M

    2004-01-01

    Of the various possible incisions for breast augmentation, the transareolar access has gained only limited popularity. The potential side effects of this incision are said to be altered nipple sensation, impaired lactation, an increased rate of infections with capsular fibrosis, well visible scar formation with hypopigmentation, and the need for an additional access in case a breast ptosis correction should prove necessary at a later date. The purpose of this retrospective study was to judge advantages and limitations of transareolar breast augmentation, and to verify whether the reluctant attitude toward this surgical approach is justified. A sample of 18 patients with a transareolar, retropectoral breast augmentation was selected for a retrospective evaluation. The suitability of the technique in general was examined together with early postoperative complications, sensory changes, and late complications on the basis of an evaluation system for cosmetic surgical results. The study showed that only women with an areolar diameter of 3.5 cm or more without pronounced breast ptosis were suitable for the transareolar access. No early infections were noted. The rate of capsular fibrosis was 11%. Two years after breast augmentation, 16 women (89%) judged their breast sensation to be normal, but objective assessment showed that mean pressure and vibration sensation were moderately compromised in all parts of the breast. The scars were of good quality, with very little hypopigmentation. With appropriate patient selection, respecting the advantages and limitations, the transareolar incision has its definite place among the different incisions for breast augmentation. PMID:15164231

  1. AB027. Penile augmentation: informed text briefing

    PubMed Central

    Park, Nam Cheol

    2016-01-01

    The men’s desire to have larger and longer penis have created endless medical demands throughout human history. Until up to date, various medical skills for penile augmentation have developed in aspect of experimental and clinical outcome. Recently with throwing away socially unacceptable ideas, the need for penile augmentation is considered as equivalent level with mammoplasty for breast augmentation in women for cosmetic and psychological reason. Concurrently advanced technologies in medical material and tissue engineering provide a variety of options to features functional plastic surgery as well as defected tissue compensation procedures. This creative description works accordingly presents state of art knowledge on the penile augmentation with more than 100 full-colored helpful illustrations clarifying penile surgical anatomy, operative procedures by experienced surgeon from the traditional fat transfer to the penile disassembly technique, the newest tissue engineering techniques by researchers with valuable data of world top level, auxiliary medical devices, and how to reconstruct for damaged penis by a quack or accident. Obviously this text book will be a great guidebook in clinical practice for all who are involved or interested in the penile augmentation procedure.

  2. Stability-Augmentation Devices for Miniature Aircraft

    NASA Technical Reports Server (NTRS)

    Wood, RIchard M.

    2005-01-01

    Non-aerodynamic mechanical devices are under consideration as means to augment the stability of miniature autonomous and remotely controlled aircraft. Such aircraft can be used for diverse purposes, including military reconnaissance, radio communications, and safety-related monitoring of wide areas. The need for stability-augmentation devices arises because adverse meteorological conditions generally affect smaller aircraft more strongly than they affect larger aircraft: Miniature aircraft often become uncontrollable under conditions that would not be considered severe enough to warrant grounding of larger aircraft. The need for the stability-augmentation devices to be non-aerodynamic arises because there is no known way to create controlled aerodynamic forces sufficient to counteract the uncontrollable meteorological forces on miniature aircraft. A stability-augmentation device of the type under consideration includes a mass pod (a counterweight) at the outer end of a telescoping shaft, plus associated equipment to support the operation of the aircraft. The telescoping shaft and mass pod are stowed in the rear of the aircraft. When deployed, they extend below the aircraft. Optionally, an antenna for radio communication can be integrated into the shaft. At the time of writing this article, the deployment of the telescoping shaft and mass pod was characterized as passive and automatic, but information about the deployment mechanism(s) was not available. The feasibility of this stability-augmentation concept was demonstrated in flights of hand-launched prototype aircraft.

  3. Relaxation damping in oscillating contacts

    PubMed Central

    Popov, M.; Popov, V.L.; Pohrt, R.

    2015-01-01

    If a contact of two purely elastic bodies with no sliding (infinite coefficient of friction) is subjected to superimposed oscillations in the normal and tangential directions, then a specific damping appears, that is not dependent on friction or dissipation in the material. We call this effect “relaxation damping”. The rate of energy dissipation due to relaxation damping is calculated in a closed analytic form for arbitrary axially-symmetric contacts. In the case of equal frequency of normal and tangential oscillations, the dissipated energy per cycle is proportional to the square of the amplitude of tangential oscillation and to the absolute value of the amplitude of normal oscillation, and is dependent on the phase shift between both oscillations. In the case of low frequency tangential oscillations with superimposed high frequency normal oscillations, the dissipation is proportional to the ratio of the frequencies. Generalization of the results for macroscopically planar, randomly rough surfaces as well as for the case of finite friction is discussed. PMID:26549011

  4. Relaxation damping in oscillating contacts

    NASA Astrophysics Data System (ADS)

    Popov, M.; Popov, V. L.; Pohrt, R.

    2015-11-01

    If a contact of two purely elastic bodies with no sliding (infinite coefficient of friction) is subjected to superimposed oscillations in the normal and tangential directions, then a specific damping appears, that is not dependent on friction or dissipation in the material. We call this effect “relaxation damping”. The rate of energy dissipation due to relaxation damping is calculated in a closed analytic form for arbitrary axially-symmetric contacts. In the case of equal frequency of normal and tangential oscillations, the dissipated energy per cycle is proportional to the square of the amplitude of tangential oscillation and to the absolute value of the amplitude of normal oscillation, and is dependent on the phase shift between both oscillations. In the case of low frequency tangential oscillations with superimposed high frequency normal oscillations, the dissipation is proportional to the ratio of the frequencies. Generalization of the results for macroscopically planar, randomly rough surfaces as well as for the case of finite friction is discussed.

  5. Orthobiologics in the augmentation of osteoporotic fractures.

    PubMed

    Watson, J Tracy; Nicolaou, Daemeon A

    2015-02-01

    Many orthobiologic adjuvants are available and widely utilized for general skeletal restoration. Their use for the specific task of osteoporotic fracture augmentation is less well recognized. Common conductive materials are reviewed for their value in this patient population including the large group of allograft adjuvants categorically known as the demineralized bone matrices (DBMs). Another large group of alloplastic materials is also examined-the calcium phosphate and sulfate ceramics. Both of these materials, when used for the proper indications, demonstrate efficacy for these patients. The inductive properties of bone morphogenic proteins (BMPs) and platelet concentrates show no clear advantages for this group of patients. Systemic agents including bisphosphonates, receptor activator of nuclear factor κβ ligand (RANKL) inhibitors, and parathyroid hormone augmentation all demonstrate positive effects with this fracture cohort. Newer modalities, such as trace ion bioceramic augmentation, are also reviewed for their positive effects on osteoporotic fracture healing. PMID:25431160

  6. The augmentation algorithm and molecular phylogenetic trees

    NASA Technical Reports Server (NTRS)

    Holmquist, R.

    1978-01-01

    Moore's (1977) augmentation procedure is discussed, and it is concluded that the procedure is valid for obtaining estimates of the total number of fixed nucleotide substitutions both theoretically and in practice, for both simulated and real data, and in agreement, for experimentally dense data sets, with stochastic estimates of the divergence, provided the restrictions on codon mutability resulting from natural selection are explicitly allowed for. Tateno and Nei's (1978) critique that the augmentation procedure has a systematic bias toward overestimation of the total number of nucleotide replacements is disputed, and a data analysis suggests that ancestral sequences inferred by the method of parsimony contain a large number of incorrectly assigned nucleotides.

  7. Minimal inframammary incision for breast augmentation

    PubMed Central

    Fanous, Nabil; Tawilé, Caroline; Brousseau, Valérie J

    2008-01-01

    The inframammary approach in breast augmentation, still the most popular technique among plastic surgeons, has always been hampered by the undesirable appearance of its scar. The present paper describes a modified approach to inframammary augmentation with saline-filled prostheses. This approach uses a very short incision, thus resulting in a much less noticeable scar. The surgical technique is easy to learn, simple to execute, does not necessitate any special equipment and gives consistent results. Decreasing the scar length to an absolute minimum ensures higher patient and surgeon satisfaction. PMID:19554159

  8. Shuffle-exchanges on augmented meshes

    NASA Technical Reports Server (NTRS)

    Bokhari, S. H.

    1984-01-01

    A mesh connected array of size N = two to the Kth power, K an integer, can be augmented by adding at most one edge per node such that it can perform a shuffle-exchange of size N/2 in constant time. A shuffle-exchange of size N is performed on this augmented array in constant time. This is done by combining the available perfect shuffle of size N/2 with the existing nearest neighbor connections of the mesh. By carefully scheduling the different permutations that are composed in order to achieve the shuffle, the time required is reduced to 5 steps, which is optimal for this network.

  9. Dielectric polarization evolution equations and relaxation times

    SciTech Connect

    Baker-Jarvis, James; Riddle, Bill; Janezic, Michael D.

    2007-05-15

    In this paper we develop dielectric polarization evolution equations, and the resulting frequency-domain expressions, and relationships for the resulting frequency dependent relaxation times. The model is based on a previously developed equation that was derived using statistical-mechanical theory. We extract relaxation times from dielectric data and give illustrative examples for the harmonic oscillator and derive expressions for the frequency-dependent relaxation times and a time-domain integrodifferential equation for the Cole-Davidson model.

  10. Dielectric relaxation in a protein matrix

    SciTech Connect

    Pierce, D.W.; Boxer, S.G.

    1992-06-25

    The dielectric relaxation of a sperm whale ApoMb-DANCA complex is measured by the fluorescence dynamic Stokes shift method. Emission energy increases with decreasing temperature, suggesting that the relaxation activation energies of the rate-limiting motions either depend on the conformational substrate or different types of protein motions with different frequencies participate in the reaction. Experimental data suggest that there may be relaxations on a scale of <100 ps. 61 refs., 7 figs., 2 tabs.

  11. Conservation of magnetic helicity during plasma relaxation

    SciTech Connect

    Ji, H.; Prager, S.C.; Sarff, J.S.

    1994-07-01

    Decay of the total magnetic helicity during the sawtooth relaxation in the MST Reversed-Field Pinch is much larger than the MHD prediction. However, the helicity decay (3--4%) is smaller than the magnetic energy decay (7--9%), modestly supportive of the helicity conservation hypothesis in Taylor`s relaxation theory. Enhanced fluctuation-induced helicity transport during the relaxation is observed.

  12. Delayed Over-Relaxation for iterative methods

    NASA Astrophysics Data System (ADS)

    Antuono, M.; Colicchio, G.

    2016-09-01

    We propose a variant of the relaxation step used in the most widespread iterative methods (e.g. Jacobi Over-Relaxation, Successive Over-Relaxation) which combines the iteration at the predicted step, namely (n + 1), with the iteration at step (n - 1). We provide a theoretical analysis of the proposed algorithm by applying such a delayed relaxation step to a generic (convergent) iterative scheme. We prove that, under proper assumptions, this significantly improves the convergence rate of the initial iterative method. As a relevant example, we apply the proposed algorithm to the solution of the Poisson equation, highlighting the advantages in comparison with classical iterative models.

  13. Baryogenesis via elementary Goldstone Higgs relaxation

    NASA Astrophysics Data System (ADS)

    Gertov, Helene; Pearce, Lauren; Sannino, Francesco; Yang, Louis

    2016-06-01

    We extend the relaxation mechanism to the elementary Goldstone Higgs framework. Besides studying the allowed parameter space of the theory, we add the minimal ingredients needed for the framework to be phenomenologically viable. The very nature of the extended Higgs sector allows to consider very flat scalar potential directions along which the relaxation mechanism can be implemented. This fact translates into wider regions of applicability of the relaxation mechanism when compared to the Standard Model Higgs case. Our results show that if the electroweak scale is not fundamental but radiatively generated it is possible to generate the observed matter-antimatter asymmetry via the relaxation mechanism.

  14. The multigrid method: Fast relaxation

    NASA Technical Reports Server (NTRS)

    South, J. C., Jr.; Brandt, A.

    1976-01-01

    A multi-level grid method was studied as a possible means of accelerating convergence in relaxation calculations for transonic flows. The method employs a hierarchy of grids, ranging from very coarse (e.g. 4 x 2 mesh cells) to fine (e.g. 64 x 32); the coarser grids are used to diminish the magnitude of the smooth part of the residuals, hopefully with far less total work than would be required with optimal iterations on the finest grid. To date the method was applied quite successfully to the solution of the transonic small-disturbance equation for the velocity potential in conservation form. Nonlifting transonic flow past a parabolic arc airfoil is the example studied, with meshes of both constant and variable step size.

  15. A Universal Logging Format for Augmentative Communication.

    ERIC Educational Resources Information Center

    Lesher, Gregory W.; Moulton, Bryan J.; Rinkus, Gerard; Higginbotham, D. Jeffery

    This report discusses how technical and technological advances in alternative and augmentative communication (AAC) have outstripped the ability to assess their impact on actual communication and argues that this is due in part to the lack of a consistent and reliable method to measure long-term communicative efficacy. The report proposes a…

  16. Location-Based Learning through Augmented Reality

    ERIC Educational Resources Information Center

    Chou, Te-Lien; Chanlin, Lih-Juan

    2014-01-01

    A context-aware and mixed-reality exploring tool cannot only effectively provide an information-rich environment to users, but also allows them to quickly utilize useful resources and enhance environment awareness. This study integrates Augmented Reality (AR) technology into smartphones to create a stimulating learning experience at a university…

  17. CARE: Creating Augmented Reality in Education

    ERIC Educational Resources Information Center

    Latif, Farzana

    2012-01-01

    This paper explores how Augmented Reality using mobile phones can enhance teaching and learning in education. It specifically examines its application in two cases, where it is identified that the agility of mobile devices and the ability to overlay context specific resources offers opportunities to enhance learning that would not otherwise exist.…

  18. Get Real: Augmented Reality for the Classroom

    ERIC Educational Resources Information Center

    Mitchell, Rebecca; DeBay, Dennis

    2012-01-01

    Kids love augmented reality (AR) simulations because they are like real-life video games. AR simulations allow students to learn content while collaborating face to face and interacting with a multimedia-enhanced version of the world around them. Although the technology may seem advanced, AR software makes it easy to develop content-based…

  19. Intelligent Augmented Reality Training for Motherboard Assembly

    ERIC Educational Resources Information Center

    Westerfield, Giles; Mitrovic, Antonija; Billinghurst, Mark

    2015-01-01

    We investigate the combination of Augmented Reality (AR) with Intelligent Tutoring Systems (ITS) to assist with training for manual assembly tasks. Our approach combines AR graphics with adaptive guidance from the ITS to provide a more effective learning experience. We have developed a modular software framework for intelligent AR training…

  20. Design Principles for Augmented Reality Learning

    ERIC Educational Resources Information Center

    Dunleavy, Matt

    2014-01-01

    Augmented reality is an emerging technology that utilizes mobile, context-aware devices (e.g., smartphones, tablets) that enable participants to interact with digital information embedded within the physical environment. This overview of design principles focuses on specific strategies that instructional designers can use to develop AR learning…

  1. Introduction to augmented and virtual reality

    NASA Astrophysics Data System (ADS)

    Caudell, Thomas P.

    1995-12-01

    This paper introduces the field of augmented reality as a prolog to the body of papers in the remainder of this session. I describe the use of head-mounted display technologies to improve the efficiency and quality of human workers in their performance of engineering design, manufacturing, construction, testing, and maintenance activities. This technology is used to `augment' the visual field of the wearer with information necessary in the performance of the current task. The enabling technology is head-up (see-through) display head sets (HUDsets) combined with head position sensing, real world registration systems, and database access software. A primary difference between virtual reality (VR) and `augmented reality' (AR) is in the complexity of the perceived graphical objects. In AR systems, only simple wire frames, template outlines, designators, and text is displayed. An immediate result of this difference is that augmented reality systems can be driven by standard and inexpensive microprocessors. Many research issues must be addressed before this technology can be widely used, including tracking and registration, human 3D perception and reasoning, and human task performance issues.

  2. E-Learning: Between Augmentation and Disruption?

    ERIC Educational Resources Information Center

    Heilesen, Simon B.; Josephsen, Jens

    2008-01-01

    Based on a framework for analysis combining diffusion theory, content layer analysis and sense making, this paper discusses the theme of "e-learning as augmentation or disruption" from the point of view of technological innovation. Two cases of on-campus blended learning at Roskilde University, Denmark, are introduced to illustrate the discussion.…

  3. Augmentative Communication: Assessment, System Selection, and Usage.

    ERIC Educational Resources Information Center

    DeRuyter, Frank; Becker, Mary R.

    1988-01-01

    Augmentative communication systems for the nonspeaking brain-injured should be carefully selected to serve a variety of functions. These include the utilization of systems for communication purposes, assessment of cognitive-linguistic deficits, integration and participation by the individual in the rehabilitation program, and improvement in an…

  4. Personalized augmented reality for anatomy education.

    PubMed

    Ma, Meng; Fallavollita, Pascal; Seelbach, Ina; Von Der Heide, Anna Maria; Euler, Ekkehard; Waschke, Jens; Navab, Nassir

    2016-05-01

    Anatomy education is a challenging but vital element in forming future medical professionals. In this work, a personalized and interactive augmented reality system is developed to facilitate education. This system behaves as a "magic mirror" which allows personalized in-situ visualization of anatomy on the user's body. Real-time volume visualization of a CT dataset creates the illusion that the user can look inside their body. The system comprises a RGB-D sensor as a real-time tracking device to detect the user moving in front of a display. In addition, the magic mirror system shows text information, medical images, and 3D models of organs that the user can interact with. Through the participation of 7 clinicians and 72 students, two user studies were designed to respectively assess the precision and acceptability of the magic mirror system for education. The results of the first study demonstrated that the average precision of the augmented reality overlay on the user body was 0.96 cm, while the results of the second study indicate 86.1% approval for the educational value of the magic mirror, and 91.7% approval for the augmented reality capability of displaying organs in three dimensions. The usefulness of this unique type of personalized augmented reality technology has been demonstrated in this paper. PMID:26646315

  5. Augmenting the ADDIE Paradigm for Instructional Design

    ERIC Educational Resources Information Center

    Ni, Xiaopeng; Branch, Robert Maribe

    2008-01-01

    The authors discuss topics appropriate for augmenting the ADDIE paradigm for instructional design. The topics selected are based on data from a study of working professionals who successfully completed an instructional design and technology certificate program and who identified related topics that they regarded as beneficial. The participants…

  6. APITRON ELECTROSTATICALLY AUGMENTED FABRIC FILTER EVALUATION

    EPA Science Inventory

    The report gives results of fractional and overall mass efficiency tests of two Apitron electrostatically augmented fabric filter dust collectors. The tests were performed on a mobile pilot-scale system collecting flyash produced by a pulverized-coal-fired industrial boiler and o...

  7. Toward natural fiducials for augmented reality

    NASA Astrophysics Data System (ADS)

    Kitchin, Paul; Martinez, Kirk

    2005-03-01

    Augmented Reality (AR) requires a mapping between the camera(s) and the world, so that virtual objects can be correctly registered. Current AR applications either use pre-prepared fiducial markers or specialist equipment or impose significant constraints on lighting and background. Each of these approaches has significant drawbacks. Fiducial markers are susceptible to loss or damage, can be awkward to work with and may require significant effort to prepare an area for Augmented interaction. Use of such markers may also present an imposition to non-augmented observers, especially in environments such as museums or historical landmarks. Specialist equipment is expensive and not universally available. Lighting and background constraints are often impractical for real-world applications. This paper presents initial results in using the palm of the hand as a pseudo-fiducial marker in a natural real-world environment, through colour, feature and edge analysis. The eventual aim of this research is to enable fiducial marker cards to be dispensed with entirely in some situations in order to allow more natural interaction in Augmented environments. Examples of this would be allowing users to "hold" virtual 3D objects in the palm of their hand or use gestures to interact with virtual objects.

  8. An Asynchronous Augmentation to Traditional Course Delivery.

    ERIC Educational Resources Information Center

    Wolverton, Marvin L.; Wolverton, Mimi

    Asynchronous augmentation facilitates distributed learning, which relies heavily on technology and self-learning. This paper reports the results of delivering a real estate principles course using an asynchronous course delivery format. It highlights one of many ways to enhance learning using technology, and it provides information concerning how…

  9. AQUEOUS RELAXATION REAGENTS IN NITROGEN-15 NMR

    EPA Science Inventory

    Electron-nuclear relaxation times T(1)supe's for 15N and 13C in natural abundance are measured for a series of amines in aqueous solution using Gd(III) complexes of a series of polyaminocarboxylate ligands as paramagnetic relaxation reagents (PARRs). The PARRs are classified by t...

  10. Dielectric secondary relaxations in polypropylene glycols.

    PubMed

    Grzybowska, K; Grzybowski, A; Zioło, J; Paluch, M; Capaccioli, S

    2006-07-28

    Broadband dielectric measurements of polypropylene glycol of molecular weight M(w)=400 g / mol (PPG 400) were carried out at ambient pressure over the wide temperature range from 123 to 353 K. Three relaxation processes were observed. Besides the structural alpha relaxation, two secondary relaxations, beta and gamma, were found. The beta process was identified as the true Johari-Goldstein relaxation by using a criterion based on the coupling model prediction. The faster gamma relaxation, well separated from the primary process, undoubtedly exhibits the anomalous behavior near the glass transition temperature (T(g)) which is reflected in the presence of a minimum of the temperature dependence of the gamma-relaxation time. We successfully applied the minimal model [Dyre and Olsen, Phys. Rev. Lett. 91, 155703 (2003)] to describe the entire temperature dependence of the gamma-relaxation time. The asymmetric double-well potential parameters obtained by Dyre and Olsen for the secondary relaxation of tripropylene glycol at ambient pressure were modified by fitting to the minimal model at lower temperatures. Moreover, we showed that the effect of the molecular weight of polypropylene glycol on the minimal model parameters is significantly larger than that of the high pressure. Such results can be explained by the smaller degree of hydrogen bonds formed by longer chain molecules of PPG at ambient pressure than that created by shorter chains of PPG at high pressure. PMID:16942189

  11. Analysis of sawtooth relaxation oscillations in tokamaks

    SciTech Connect

    Yamazaki, K.; McGuire, K.; Okabayashi, M.

    1982-07-01

    Sawtooth relaxation oscillations are analyzed using the Kadomtsev's disruption model and a thermal relaxation model. The sawtooth period is found to be very sensitive to the thermal conduction loss. Qualitative agreement between these calculations and the sawtooth period observed in several tokamaks is demonstrated.

  12. Magnetization Transfer Induced Biexponential Longitudinal Relaxation

    PubMed Central

    Prantner, Andrew M.; Bretthorst, G. Larry; Neil, Jeffrey J.; Garbow, Joel R.; Ackerman, Joseph J.H.

    2009-01-01

    Longitudinal relaxation of brain water 1H magnetization in mammalian brain in vivo is typically analyzed on a per voxel basis using a monoexponential model, thereby assigning a single relaxation time constant to all 1H magnetization within a given voxel. This approach was tested by obtaining inversion recovery data from grey matter of rats at 64 exponentially-spaced recovery times. Using Bayesian probability for model selection, brain water data were best represented by a biexponential function characterized by fast and slow relaxation components. At 4.7 T, the amplitude fraction of the rapidly relaxing component is 3.4 ± 0.7 % with a rate constant of 44 ± 12 s-1 (mean ± SD; 174 voxels from 4 rats). The rate constant of the slow relaxing component is 0.66 ± 0.04 s-1. At 11.7 T, the corresponding values are 6.9 ± 0.9 %, 19 ± 5 s-1, and 0.48 ± 0.02 s-1 (151 voxels from 4 rats). Several putative mechanisms for biexponential relaxation behavior were evaluated, and magnetization transfer between bulk water protons and non-aqueous protons was determined to be the source of biexponential longitudinal relaxation. MR methods requiring accurate quantification of longitudinal relaxation may need to take this effect explicitly into account. PMID:18759367

  13. Relaxed States in Magnetized Pair Plasmas

    NASA Astrophysics Data System (ADS)

    Shukla, P. K.; Mahajan, S. M.

    2004-01-01

    We discuss possibility of possible relaxed states in magnetized pair plasmas. It is shown that stationary relaxed states are described by the double curl Beltrami/Mahajan-Yoshida equation. We can thus have steady state tructures on the scale sizes of the order of the electron (ion) skin depth in an electron-positron (electron-positron-ion) plasma.

  14. 3D photography in the objective analysis of volume augmentation including fat augmentation and dermal fillers.

    PubMed

    Meier, Jason D; Glasgold, Robert A; Glasgold, Mark J

    2011-11-01

    The authors present quantitative and objective 3D data from their studies showing long-term results with facial volume augmentation. The first study analyzes fat grafting of the midface and the second study presents augmentation of the tear trough with hyaluronic filler. Surgeons using 3D quantitative analysis can learn the duration of results and the optimal amount to inject, as well as showing patients results that are not demonstrable with standard, 2D photography. PMID:22004863

  15. On relaxations and aging of various glasses

    PubMed Central

    Amir, Ariel; Oreg, Yuval; Imry, Yoseph

    2012-01-01

    Slow relaxation occurs in many physical and biological systems. “Creep” is an example from everyday life. When stretching a rubber band, for example, the recovery to its equilibrium length is not, as one might think, exponential: The relaxation is slow, in many cases logarithmic, and can still be observed after many hours. The form of the relaxation also depends on the duration of the stretching, the “waiting time.” This ubiquitous phenomenon is called aging, and is abundant both in natural and technological applications. Here, we suggest a general mechanism for slow relaxations and aging, which predicts logarithmic relaxations, and a particular aging dependence on the waiting time. We demonstrate the generality of the approach by comparing our predictions to experimental data on a diverse range of physical phenomena, from conductance in granular metals to disordered insulators and dirty semiconductors, to the low temperature dielectric properties of glasses. PMID:22315418

  16. On relaxations and aging of various glasses.

    PubMed

    Amir, Ariel; Oreg, Yuval; Imry, Yoseph

    2012-02-01

    Slow relaxation occurs in many physical and biological systems. "Creep" is an example from everyday life. When stretching a rubber band, for example, the recovery to its equilibrium length is not, as one might think, exponential: The relaxation is slow, in many cases logarithmic, and can still be observed after many hours. The form of the relaxation also depends on the duration of the stretching, the "waiting time." This ubiquitous phenomenon is called aging, and is abundant both in natural and technological applications. Here, we suggest a general mechanism for slow relaxations and aging, which predicts logarithmic relaxations, and a particular aging dependence on the waiting time. We demonstrate the generality of the approach by comparing our predictions to experimental data on a diverse range of physical phenomena, from conductance in granular metals to disordered insulators and dirty semiconductors, to the low temperature dielectric properties of glasses. PMID:22315418

  17. Effect of filler surface properties on stress relaxation behavior of carbon nanofiber/polyurethane nanocomposites

    NASA Astrophysics Data System (ADS)

    Sedat Gunes, I.; Jimenez, Guillermo; Jana, Sadhan

    2009-03-01

    The effect of carbon nanofiber (CNF) surface properties on tensile stress relaxation behavior of CNF/polyurethane (PU) nanocomposites was analyzed. PU was synthesized from methylene diisocyanate, polypropylene glycol (PPG diol), and butanediol. CNF, oxidized CNF (ox-CNF), and PPG diol grafted CNF (ol-CNF) were selected as fillers. ol-CNF was obtained by grafting PPG diol onto ox-CNF by reacting it with the carboxyl groups present on ox-CNF surface. The atomic ratios of oxygen to carbon present on the filler surfaces were 0.13 and 0.18 on ox-CNF and on ol-CNF as compared to 0.015 on CNF, mostly due to the presence oxygen containing polar groups on the surfaces of the former. The composites were prepared by in-situ polymerization and melt mixing in a chaotic mixer. The stress relaxation behavior of composites was determined at room temperature after inducing a tensile strain of 100%. The presence of fillers augmented the rate of stress relaxation in composites which was highest in the presence of CNF. The results suggested that relatively weak polymer-filler interactions in composites of CNF promoted higher stress relaxation.

  18. Nuclear spin relaxation of polycrystalline 129 xenon

    NASA Astrophysics Data System (ADS)

    Samuelson, Gary Lee, Jr.

    Through spin exchange optical pumping, it is possible to achieve upwards of 30% nuclear spin polarization in 129Xe with an NMR signal enhancement of some 5 orders of magnitude over typical thermal signals. Hyperpolarized 129Xe has thus found application in several leading-edge technologies. At 1 T and 4.2 K, the characteristic relaxation time of enriched polycrystalline 129Xe (86% 129Xe, 0.1% 131Xe) is well over 200 hrs, sufficient for long-term storage and transport. Longitudinal nuclear spin relaxation of 129Xe at more convenient fields from 1 to 200 G is studied in detail. Significant structure in relaxation times vs. magnetic field is seen; the most prominent new finding being a sharp local long-time T 1 maximum of 1000 mins at ≈3 G. Such structure has not been observed in previous measurements of natural Xe. Below temperatures of 10 K, relaxation can be attributed to cross relaxation with 131Xe, mediated by spin diffusion. Measurements of 129Xe relaxation as a function of magnetic field, temperature and Xe isotopic content are reported and compared with expected theoretical behaviors. It is seen that the characteristic nuclear spin relaxation of enriched 129Xe at 4.2 K is nonexponential at these low fields. For fields between 10 G and 200 G, these nonexponential relaxation curves can be fit well with a specific spin diffusion model. Below 10 G no such fit is possible and thus quantum mechanical details of the coupling between 129Xe, 131Xe and the bulk lattice are considered. These findings support the hypothesis that cross relaxation with 131Xe is indeed a dominant actor in the nuclear spin relaxation of polycrystalline 129 Xe at such low fields and low temperatures.

  19. Postseismic relaxation and transient creep

    USGS Publications Warehouse

    Savage, J.C.; Svarc, J.L.; Yu, S.-B.

    2005-01-01

    Postseismic deformation has been observed in the epicentral area following the 1992 Landers (M = 7.3), 1999 Chi-Chi (M = 7.6), 1999 Hector Mine (M = 7.1), 2002 Denali (M = 7.9), 2003 San Simeon (M = 6.5), and 2004 Parkfield (M = 6.0) earthquakes. The observations consist of repeated GPS measurements of the position of one monument relative to another (separation ???100 km). The early observations (t < 0.1 year) are well fit by the function a' + c'log(t), where t is the time after the earthquake and a' and c' are constants chosen to fit the data. Because a log(t) time dependence is characteristic of transient (primary) creep, the early postseismic response may be governed by transient creep as Benioff proposed in 1951. That inference is provisional as the stress conditions prevailing in postseismic relaxation are not identical to the constant stress condition in creep experiments. The observed logarithmic time dependence includes no characteristic time that might aid in identifying the micromechanical cause.

  20. Relaxation time of 3He

    NASA Astrophysics Data System (ADS)

    Gao, Hayian

    2004-10-01

    The next generation of searches for the neutron electric dipole moment using ultra cold neutrons will use polarized ^3He as a co-magnetometer. The first such experiment has been proposed, with a goal of improving the current limit on the neutron EDM by two orders of magnitude. This experiment requires a systematic study of the properties of polarized ^3He at cryogenic temperatures under actual experimental conditions. These experimental conditions include polarized ^3He mixed in a bath of superfluid ^4He in low magnetic field and held in an acrylic cell which is coated with deuterated TetraphenylButadiene . Parts of these systematic studies will be done at Duke University using a newly built, novel refillable double cell ^3 He polarizer based on spin exchange optical pumping with Rubidium vapor. The polarimetry for this apparatus is done with a NMR polarimeter using the adiabatic fast passage method. An alternate polarimeter using free induction decay method is also being built. This apparatus is being used to study the relaxation time and other critical properties of polarized ^3He at temperatures ranging from 2.3 - 4.2 K, under simulated experimental conditions. We will present details about this novel polarizer and show preliminary results of our measurements.

  1. Detonation wave augmentation of gas turbines

    NASA Technical Reports Server (NTRS)

    Wortman, A.

    1984-01-01

    The results of a feasibility study that examined the effects of using detonation waves to augment the performance of gas turbines are reported. The central ideas were to reduce compressor requirements and to maintain high performance in jet engines. Gasdynamic equations were used to model the flows associated with shock waves generated by the detonation of fuel in detonator tubes. Shock wave attenuation to the level of Mach waves was found possible, thus eliminating interference with the compressor and the necessity of valves and seals. A preliminary parametric study of the performance of a compressor working at a 4:1 ratio in a conceptual design of a detonation wave augmented jet engine in subsonic flight indicated a clear superiority over conventional designs in terms of fuel efficiency and thrust.

  2. Vertebral Augmentation: State of the Art.

    PubMed

    Sebaaly, Amer; Nabhane, Linda; Issa El Khoury, Fouad; Kreichati, Gaby; El Rachkidi, Rami

    2016-04-01

    Osteoporotic vertebral compression fractures (OVF) are an increasing public health problem. Cement augmentation (vertebroplasty of kyphoplasty) helps stabilize painful OVF refractory to medical treatment. This stabilization is thought to improve pain and functional outcome. Vertebroplasty consists of injecting cement into a fractured vertebra using a percutaneous transpedicular approach. Balloon kyphoplasty uses an inflatable balloon prior to injecting the cement. Although kyphoplasty is associated with significant improvement of local kyphosis and less cement leakage, this does not result in long-term clinical and functional improvement. Moreover, vertebroplasty is favored by some due to the high cost of kyphoplasty. The injection of cement increases the stiffness of the fracture vertebrae. This can lead, in theory, to adjacent OVF. However, many studies found no increase of subsequent fracture when comparing medical treatment to cement augmentation. Kyphoplasty can have a protective effect due to restoration of sagittal balance. PMID:27114782

  3. An Augmentation of G-Guidance Algorithms

    NASA Technical Reports Server (NTRS)

    Carson, John M. III; Acikmese, Behcet

    2011-01-01

    The original G-Guidance algorithm provided an autonomous guidance and control policy for small-body proximity operations that took into account uncertainty and dynamics disturbances. However, there was a lack of robustness in regards to object proximity while in autonomous mode. The modified GGuidance algorithm was augmented with a second operational mode that allows switching into a safety hover mode. This will cause a spacecraft to hover in place until a mission-planning algorithm can compute a safe new trajectory. No state or control constraints are violated. When a new, feasible state trajectory is calculated, the spacecraft will return to standard mode and maneuver toward the target. The main goal of this augmentation is to protect the spacecraft in the event that a landing surface or obstacle is closer or further than anticipated. The algorithm can be used for the mitigation of any unexpected trajectory or state changes that occur during standard mode operations

  4. Augmenting Probabilistic Risk Assesment with Malevolent Initiators

    SciTech Connect

    Curtis Smith; David Schwieder

    2011-11-01

    As commonly practiced, the use of probabilistic risk assessment (PRA) in nuclear power plants only considers accident initiators such as natural hazards, equipment failures, and human error. Malevolent initiators are ignored in PRA, but are considered the domain of physical security, which uses vulnerability assessment based on an officially specified threat (design basis threat). This paper explores the implications of augmenting and extending existing PRA models by considering new and modified scenarios resulting from malevolent initiators. Teaming the augmented PRA models with conventional vulnerability assessments can cost-effectively enhance security of a nuclear power plant. This methodology is useful for operating plants, as well as in the design of new plants. For the methodology, we have proposed an approach that builds on and extends the practice of PRA for nuclear power plants for security-related issues. Rather than only considering 'random' failures, we demonstrated a framework that is able to represent and model malevolent initiating events and associated plant impacts.

  5. Improved approximations for control augmented structural synthesis

    NASA Technical Reports Server (NTRS)

    Thomas, H. L.; Schmit, L. A.

    1990-01-01

    A methodology for control-augmented structural synthesis is presented for structure-control systems which can be modeled as an assemblage of beam, truss, and nonstructural mass elements augmented by a noncollocated direct output feedback control system. Truss areas, beam cross sectional dimensions, nonstructural masses and rotary inertias, and controller position and velocity gains are treated simultaneously as design variables. The structural mass and a control-system performance index can be minimized simultaneously, with design constraints placed on static stresses and displacements, dynamic harmonic displacements and forces, structural frequencies, and closed-loop eigenvalues and damping ratios. Intermediate design-variable and response-quantity concepts are used to generate new approximations for displacements and actuator forces under harmonic dynamic loads and for system complex eigenvalues. This improves the overall efficiency of the procedure by reducing the number of complete analyses required for convergence. Numerical results which illustrate the effectiveness of the method are given.

  6. Vertebral Augmentation: State of the Art

    PubMed Central

    Nabhane, Linda; Issa El Khoury, Fouad; Kreichati, Gaby; El Rachkidi, Rami

    2016-01-01

    Osteoporotic vertebral compression fractures (OVF) are an increasing public health problem. Cement augmentation (vertebroplasty of kyphoplasty) helps stabilize painful OVF refractory to medical treatment. This stabilization is thought to improve pain and functional outcome. Vertebroplasty consists of injecting cement into a fractured vertebra using a percutaneous transpedicular approach. Balloon kyphoplasty uses an inflatable balloon prior to injecting the cement. Although kyphoplasty is associated with significant improvement of local kyphosis and less cement leakage, this does not result in long-term clinical and functional improvement. Moreover, vertebroplasty is favored by some due to the high cost of kyphoplasty. The injection of cement increases the stiffness of the fracture vertebrae. This can lead, in theory, to adjacent OVF. However, many studies found no increase of subsequent fracture when comparing medical treatment to cement augmentation. Kyphoplasty can have a protective effect due to restoration of sagittal balance. PMID:27114782

  7. Tests on Thrust Augmenters for Jet Propulsion

    NASA Technical Reports Server (NTRS)

    Jacobs, Eastman N; Shoemaker, James M

    1932-01-01

    This series of tests was undertaken to determine how much the reaction thrust of a jet could be increased by the use of thrust augmenters and thus to give some indication as to the feasibility of jet propulsion for airplanes. The tests were made during the first part of 1927 at the Langley Memorial Aeronautical Laboratory. A compressed air jet was used in connection with a series of annular guides surrounding the jet to act as thrust augmenters. The results show that, although it is possible to increase the thrust of a jet, the increase is not large enough to affect greatly the status of the problem of the application of jet propulsion to airplanes.

  8. Augmentation Mammaplasty Using Implants: A Review

    PubMed Central

    2012-01-01

    One of the techniques for augmentation mammaplasty is the procedure using implants. Even though this technique has been used for many years, there are still several controversial issues to be discussed and overcome for patient safety. In this review article, capsular contracture, leak or rupture of the implants, possible systemic disease, relation with breast cancer, and recent problems with Poly Implant Prothese implants are described and discussed. PMID:23094237

  9. Augmented reality visualization for thoracoscopic spine surgery

    NASA Astrophysics Data System (ADS)

    Sauer, Frank; Vogt, Sebastian; Khamene, Ali; Heining, Sandro; Euler, Ekkehard; Schneberger, Marc; Zuerl, Konrad; Mutschler, Wolf

    2006-03-01

    We are developing an augmented reality (AR) image guidance system in which information derived from medical images is overlaid onto a video view of the patient. The centerpiece of the system is a head-mounted display custom fitted with two miniature color video cameras that capture the stereo view of the scene. Medical graphics is overlaid onto the video view and appears firmly anchored in the scene, without perceivable time lag or jitter. We have been testing the system for different clinical applications. In this paper we discuss minimally invasive thoracoscopic spine surgery as a promising new orthopedic application. In the standard approach, the thoracoscope - a rigid endoscope - provides visual feedback for the minimally invasive procedure of removing a damaged disc and fusing the two neighboring vertebrae. The navigation challenges are twofold. From a global perspective, the correct vertebrae on the spine have to be located with the inserted instruments. From a local perspective, the actual spine procedure has to be performed precisely. Visual feedback from the thoracoscope provides only limited support for both of these tasks. In the augmented reality approach, we give the surgeon additional anatomical context for the navigation. Before the surgery, we derive a model of the patient's anatomy from a CT scan, and during surgery we track the location of the surgical instruments in relation to patient and model. With this information, we can help the surgeon in both the global and local navigation, providing a global map and 3D information beyond the local 2D view of the thoracoscope. Augmented reality visualization is a particularly intuitive method of displaying this information to the surgeon. To adapt our augmented reality system to this application, we had to add an external optical tracking system, which works now in combination with our head-mounted tracking camera. The surgeon's feedback to the initial phantom experiments is very positive.

  10. Ligament reconstruction tendon interposition with mersilene augmentation.

    PubMed

    Stein, Andrew J; Schofield, Jennifer L; Marsh, Mike; Paulo, Jerry

    2011-03-01

    Many surgical procedures have been described for the treatment of thumb basilar joint osteoarthritis. Augmentation of the standard ligament reconstruction tendon interposition procedure with the use of a Mersilene suture tape suspension-plasty, to recreate the stability provided by the anterior oblique ligament and increase pinch strength, will be described. Satisfaction with this procedure was evaluated through surveys completed by patients. In addition, independent physical assessments were performed to demonstrate stability, range of motion, and strength. PMID:21358518

  11. Asian Breast Augmentation: A Systematic Review

    PubMed Central

    Zelken, Jonathan

    2015-01-01

    Background: Economic, cultural, and regulatory phenomena may explain recent popularization of implant-based augmentation in Asia; but the collective Eastern experience remains limited. Asian surgeons and their patients rely on evidence-based medicine that originates elsewhere and may not be entirely relevant. Distinct anatomic and cultural features of Asian women warrant a tailored approach to breast augmentation. We explore the Asian experience with a thorough exploration of the recent literature. Methods: A literature search was performed for articles written after 2000, of Asian women who underwent augmentation mammoplasty using MEDLINE, Embase, and Pubmed Databases. Technique and outcomes data were summarized. Results: Twelve articles reported outcomes of 2089 women. Korea contributed most series (English language, 7), followed by China (3), Taiwan (1), and Japan (1). Silicone implants were used in 82.1% of women studied, and almost exclusively after 2009. More round (68.9%) than anatomic implants (31.1%) were placed. Non-inframammary (axillary, areolar, and umbilical) incisions were used in 96.9% of cases. Nearly all implants were positioned below the muscle or fascia; subglandular placement accounted for 1.1% of cases. Implant/nipple malposition (1.3%), capsular contracture (1.9%), hematoma (0.6%), and infection (0.2%) rates were reported in most series. Undesirable scarring was the most frequent complication (7.3%), but was reported only in 4 of 12 series. Conclusions: Studies of Asian women undergoing augmentation mammoplasty are limited, often with ill-defined outcomes and inadequate follow-up. As experience accumulates, an expanding literature relevant to Asian women will provide evidence-based guidelines that improve outcomes and patient satisfaction, and foster innovation. PMID:26893980

  12. Primary Breast Augmentation with Fat Grafting.

    PubMed

    Coleman, Sydney R; Saboeiro, Alesia P

    2015-07-01

    The controversy over fat grafting to the breasts has now been settled. In 2009, the American Society of Plastic Surgeons Fat Graft Task Force stated that "Fat grafting may be considered for breast augmentation and correction of defects associated with medical conditions and previous breast surgeries; however, results are dependent on technique and surgeon expertise." This article discusses the history, indications, planning, complications, and present technique of fat grafting to the breast using the Coleman technique. PMID:26116935

  13. Ceramic augmentation of the lower jaw.

    PubMed

    Bunte, M; Strunz, V

    1977-11-01

    Atrophy of the lower jaw is essentially a manifestation of vertical bone resorption and must be treated in a compensatory manner. Animal experiments have shown the value of the bioactive glass ceramic Ceravital as a bone replacement material. After box-shaped or step-shaped osteotomies, we perform interpositional plastic operations with glass ceramic in order to augment the atrophied human lower jaw. Results, advantages and dangers of the method are shown in 12 patients. PMID:271190

  14. Percutaneous Vertebral Body Augmentation: An Updated Review

    PubMed Central

    Omidi-Kashani, Farzad

    2014-01-01

    There are many medical conditions like osteoporosis, tumor, or osteonecrosis that weaken the structural strength of the vertebral body and prone it to fracture. Percutaneous vertebral augmentation that is usually applied by polymethylmethacrylate is a relatively safe, effective, and long lasting procedure commonly performed in these situations. In this paper, we updated a review of biomechanics, indications, contraindications, surgical techniques, complications, and overall prognosis of these minimally invasive spinal procedures. PMID:25379561

  15. Service connectivity architecture for mobile augmented reality

    NASA Astrophysics Data System (ADS)

    Turunen, Tuukka; Pyssysalo, Tino; Roening, Juha

    2001-06-01

    Mobile augmented reality can be utilized in a number of different services, and it provides a lot of added value compared to the interfaces used in mobile multimedia today. Intelligent service connectivity architecture is needed for the emerging commercial mobile augmented reality services, to guarantee mobility and interoperability on a global scale. Some of the key responsibilities of this architecture are to find suitable service providers, to manage the connection with and utilization of such providers, and to allow smooth switching between them whenever the user moves out of the service area of the service provider she is currently connected to. We have studied the potential support technologies for such architectures and propose a way to create an intelligent service connectivity architecture based on current and upcoming wireless networks, an Internet backbone, and mechanisms to manage service connectivity in the upper layers of the protocol stack. In this paper, we explain the key issues of service connectivity, describe the properties of our architecture, and analyze the functionality of an example system. Based on these, we consider our proposition a good solution to the quest for global interoperability in mobile augmented reality services.

  16. Silicone-induced Granuloma After Buttock Augmentation

    PubMed Central

    Singh, Mansher; Solomon, Isaac H.; Calderwood, Michael S.

    2016-01-01

    Summary: Liquid silicone is inexpensive, minimally antigenic, and likely noncarcinogenic. Its simplicity of use has made it popular as a soft-tissue filler in some parts of the world for patients seeking rapid soft-tissue augmentation of the face, breast, and buttocks. However, multiple reports describe the complications of silicone injections such as cellulitis, abscess, ulceration, and foreign body migration. We present an unusual complication of granulomatous reaction secondary to silicone injection for buttock augmentation, with a literature review of this entity and treatment options. Our patient was a 54-year-old woman who underwent bilateral buttock augmentation in the Dominican Republic using percutaneous injection of liquid silicone. She presented to our facility 1 year after this procedure with pain and inflammation of both buttocks. She was diagnosed with multiple silicone granulomas. Her symptoms completely resolved with a 3-week course of minocycline. Granulomatous reactions to silicone may occur months to years after the silicone injection. The incidence of such complications may be increased when nonmedical-grade silicone is used, and hence, when these procedures are performed in developing countries. Tetracycline antibiotics, especially minocycline, may be used to achieve sustained remission. PMID:27014553

  17. Augmented classical least squares multivariate spectral analysis

    DOEpatents

    Haaland, David M.; Melgaard, David K.

    2004-02-03

    A method of multivariate spectral analysis, termed augmented classical least squares (ACLS), provides an improved CLS calibration model when unmodeled sources of spectral variation are contained in a calibration sample set. The ACLS methods use information derived from component or spectral residuals during the CLS calibration to provide an improved calibration-augmented CLS model. The ACLS methods are based on CLS so that they retain the qualitative benefits of CLS, yet they have the flexibility of PLS and other hybrid techniques in that they can define a prediction model even with unmodeled sources of spectral variation that are not explicitly included in the calibration model. The unmodeled sources of spectral variation may be unknown constituents, constituents with unknown concentrations, nonlinear responses, non-uniform and correlated errors, or other sources of spectral variation that are present in the calibration sample spectra. Also, since the various ACLS methods are based on CLS, they can incorporate the new prediction-augmented CLS (PACLS) method of updating the prediction model for new sources of spectral variation contained in the prediction sample set without having to return to the calibration process. The ACLS methods can also be applied to alternating least squares models. The ACLS methods can be applied to all types of multivariate data.

  18. Augmented Classical Least Squares Multivariate Spectral Analysis

    DOEpatents

    Haaland, David M.; Melgaard, David K.

    2005-01-11

    A method of multivariate spectral analysis, termed augmented classical least squares (ACLS), provides an improved CLS calibration model when unmodeled sources of spectral variation are contained in a calibration sample set. The ACLS methods use information derived from component or spectral residuals during the CLS calibration to provide an improved calibration-augmented CLS model. The ACLS methods are based on CLS so that they retain the qualitative benefits of CLS, yet they have the flexibility of PLS and other hybrid techniques in that they can define a prediction model even with unmodeled sources of spectral variation that are not explicitly included in the calibration model. The unmodeled sources of spectral variation may be unknown constituents, constituents with unknown concentrations, nonlinear responses, non-uniform and correlated errors, or other sources of spectral variation that are present in the calibration sample spectra. Also, since the various ACLS methods are based on CLS, they can incorporate the new prediction-augmented CLS (PACLS) method of updating the prediction model for new sources of spectral variation contained in the prediction sample set without having to return to the calibration process. The ACLS methods can also be applied to alternating least squares models. The ACLS methods can be applied to all types of multivariate data.

  19. Augmented Classical Least Squares Multivariate Spectral Analysis

    DOEpatents

    Haaland, David M.; Melgaard, David K.

    2005-07-26

    A method of multivariate spectral analysis, termed augmented classical least squares (ACLS), provides an improved CLS calibration model when unmodeled sources of spectral variation are contained in a calibration sample set. The ACLS methods use information derived from component or spectral residuals during the CLS calibration to provide an improved calibration-augmented CLS model. The ACLS methods are based on CLS so that they retain the qualitative benefits of CLS, yet they have the flexibility of PLS and other hybrid techniques in that they can define a prediction model even with unmodeled sources of spectral variation that are not explicitly included in the calibration model. The unmodeled sources of spectral variation may be unknown constituents, constituents with unknown concentrations, nonlinear responses, non-uniform and correlated errors, or other sources of spectral variation that are present in the calibration sample spectra. Also, since the various ACLS methods are based on CLS, they can incorporate the new prediction-augmented CLS (PACLS) method of updating the prediction model for new sources of spectral variation contained in the prediction sample set without having to return to the calibration process. The ACLS methods can also be applied to alternating least squares models. The ACLS methods can be applied to all types of multivariate data.

  20. Ridge augmentation in an organ transplant patient.

    PubMed

    Dalla Torre, D; Burtscher, D

    2016-05-01

    With the continuing progress in medicine, the number of successful organ transplantations has continued to increase, a fact that also concerns dentists and implantologists. Implantology after organ transplantation remains controversial due to the patient's immunocompromised situation and the corresponding risk of infection. Only a few studies on this topic have been reported, with all of them showing the dental implant success rates in transplant patients to be similar to those in healthy subjects. However, immunosuppression has been identified as a contraindication to bone augmentation. Consequently, there is still a lack of knowledge regarding pre-implantology bone grafting procedures. The following case report describes the use of ridge augmentation and extended bilateral sinus lift procedures in a liver transplant patient. The patient was treated with an implant-supported fixed prosthesis in the upper jaw and was followed up for a total of 28 months after implant insertion. According to the findings presented, pre-implantology augmentation procedures may be performed successfully in immunosuppressed organ transplant patients. Stable peri-implant conditions were shown over a period of more than 2 years. Nevertheless, further investigations are needed to define a safe treatment protocol for these high-risk patients. PMID:26711250

  1. Silicone-induced Granuloma After Buttock Augmentation.

    PubMed

    Singh, Mansher; Solomon, Isaac H; Calderwood, Michael S; Talbot, Simon G

    2016-02-01

    Liquid silicone is inexpensive, minimally antigenic, and likely noncarcinogenic. Its simplicity of use has made it popular as a soft-tissue filler in some parts of the world for patients seeking rapid soft-tissue augmentation of the face, breast, and buttocks. However, multiple reports describe the complications of silicone injections such as cellulitis, abscess, ulceration, and foreign body migration. We present an unusual complication of granulomatous reaction secondary to silicone injection for buttock augmentation, with a literature review of this entity and treatment options. Our patient was a 54-year-old woman who underwent bilateral buttock augmentation in the Dominican Republic using percutaneous injection of liquid silicone. She presented to our facility 1 year after this procedure with pain and inflammation of both buttocks. She was diagnosed with multiple silicone granulomas. Her symptoms completely resolved with a 3-week course of minocycline. Granulomatous reactions to silicone may occur months to years after the silicone injection. The incidence of such complications may be increased when nonmedical-grade silicone is used, and hence, when these procedures are performed in developing countries. Tetracycline antibiotics, especially minocycline, may be used to achieve sustained remission. PMID:27014553

  2. Fiber Creep Evaluation by Stress Relaxation Measurements

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Dicarlo, James A.; Wagner, Timothy

    1991-01-01

    A simple bend stress relaxation (BSR) test has been used to measure the creep related properties of a chemically vapor-deposited SiC fiber. Time, temperature, and strain dependent BSR data were analyzed to ascertain the ability of the stress relaxation results to predict tensile creep as a function of the same parameters. The predictions compared very well to actual creep data obtained by axial measurements, indicating that the BSR test could be used for determining both creep and stress relaxation of polycrystalline ceramic fibers under tensile loading.

  3. Collisionless Relaxation in Non-Neutral Plasmas

    SciTech Connect

    Levin, Yan; Pakter, Renato; Teles, Tarcisio N.

    2008-02-01

    A theoretical framework is presented which allows us to quantitatively predict the final stationary state achieved by a non-neutral plasma during a process of collisionless relaxation. As a specific application, the theory is used to study relaxation of charged-particle beams. It is shown that a fully matched beam relaxes to the Lynden-Bell distribution. However, when a mismatch is present and the beam oscillates, parametric resonances lead to a core-halo phase separation. The approach developed accounts for both the density and the velocity distributions in the final stationary state.

  4. A quantum-mechanical relaxation model

    NASA Astrophysics Data System (ADS)

    Skomski, R.; Kashyap, A.; Sellmyer, D. J.

    2012-04-01

    The atomic origin of micromagnetic damping is investigated by developing and solving a quantum-mechanical relaxation model. A projection-operator technique is used to derive an analytical expression for the relaxation time as a function of the heat-bath and interaction parameters. The present findings are consistent with earlier research beyond the Landau-Lifshitz-Gilbert (LLG) equation and show that the underlying relaxation mechanism is very general. Zermelo's recurrence paradox means that there is no true irreversibility in non-interacting nanoparticles, but the corresponding recurrence times are very long and can be ignored in many cases.

  5. Violation of detailed balance accelerates relaxation

    NASA Astrophysics Data System (ADS)

    Ichiki, Akihisa; Ohzeki, Masayuki

    2013-08-01

    Recent studies have experienced the acceleration of convergence in Markov chain Monte Carlo methods implemented by the systems without detailed balance condition (DBC). However, such advantage of the violation of DBC has not been confirmed in general. We investigate the effect of the absence of DBC on the convergence toward equilibrium. Surprisingly, it is shown that the DBC violation always makes the relaxation faster. Our result implies the existence of a kind of thermodynamic inequality that connects the nonequilibrium process relaxing toward steady state with the relaxation process which has the same probability distribution as its equilibrium state.

  6. Relaxation time in disordered molecular systems

    SciTech Connect

    Rocha, Rodrigo P.; Freire, José A.

    2015-05-28

    Relaxation time is the typical time it takes for a closed physical system to attain thermal equilibrium. The equilibrium is brought about by the action of a thermal reservoir inducing changes in the system micro-states. The relaxation time is intuitively expected to increase with system disorder. We derive a simple analytical expression for this dependence in the context of electronic equilibration in an amorphous molecular system model. We find that the disorder dramatically enhances the relaxation time but does not affect its independence of the nature of the initial state.

  7. Relaxation of vibrational degrees of freedom

    NASA Astrophysics Data System (ADS)

    Frohn, A.

    Shock tubes were used to measure relaxation times of the degrees of freedom in inelastic collisions of gas molecules. Design and construction of the experimental setup are described. For relaxation time measurements of vibrational degrees of freedom an initial pressure between 0.1 and 1 mbar is found to be optimal, and for dissociation between 1 and 10 mbar. The density gradients in the shock tube flow are measured with four differential laser interferometers and plotted with a transient recorder. A FORTRAN program was developed to determine the relaxation times. This measurement technique does not in general allow the degrees of freedom to be investigated separately.

  8. Momentum relaxation of a relativistic Brownian particle.

    PubMed

    Felderhof, B U

    2012-12-01

    The momentum relaxation of a relativistic Brownian particle immersed in a fluid is studied on the basis of the Fokker-Planck equation for the relativistic Ornstein-Uhlenbeck process. An analytical expression is derived for the short-time relaxation rate. The relaxation spectrum has both discrete and continuum components. It is shown that the Fokker-Planck equation under consideration is closely related to the Schrödinger equation for the hydrogen atom. Hence it follows that there is an infinite number of discrete states. The momentum autocorrelation function is calculated numerically for a strongly relativistic particle. PMID:23367889

  9. Basic MR relaxation mechanisms and contrast agent design.

    PubMed

    De León-Rodríguez, Luis M; Martins, André F; Pinho, Marco C; Rofsky, Neil M; Sherry, A Dean

    2015-09-01

    The diagnostic capabilities of magnetic resonance imaging (MRI) have undergone continuous and substantial evolution by virtue of hardware and software innovations and the development and implementation of exogenous contrast media. Thirty years since the first MRI contrast agent was approved for clinical use, a reliance on MR contrast media persists, largely to improve image quality with higher contrast resolution and to provide additional functional characterization of normal and abnormal tissues. Further development of MR contrast media is an important component in the quest for continued augmentation of diagnostic capabilities. In this review we detail the many important considerations when pursuing the design and use of MR contrast media. We offer a perspective on the importance of chemical stability, particularly kinetic stability, and how this influences one's thinking about the safety of metal-ligand-based contrast agents. We discuss the mechanisms involved in MR relaxation in the context of probe design strategies. A brief description of currently available contrast agents is accompanied by an in-depth discussion that highlights promising MRI contrast agents in the development of future clinical and research applications. Our intention is to give a diverse audience an improved understanding of the factors involved in developing new types of safe and highly efficient MR contrast agents and, at the same time, provide an appreciation of the insights into physiology and disease that newer types of responsive agents can provide. PMID:25975847

  10. Low-temperature relaxations in amorphous polyolefins

    NASA Technical Reports Server (NTRS)

    Hiltner, A.; Baer, E.; Martin, J. R.; Gillham, J. K.

    1974-01-01

    The dynamic mechanical relaxation behavior of two series of amorphous polyolefins, was investigated from 4.2 K to the glass transition. Most of the polymers show a damping maximum or plateau in the 40 to 50 K region. Various mechanisms which have been suggested for cryogenic relaxations in amorphous polymers are considered as they might relate to the polyolefins. Two secondary relaxation processes above 80 K are distinguished. A relaxation at about 160 K (beta) in the second and third member of each series is associated with restricted blackbone motion. This process requires a certain degree of chain flexibility since it is not observed in the first member of each series. A lower temperature process (gamma) is observed in each member of the second series and is attributed to motion of the ethyl side group.