RAVE—a Detector-independent vertex reconstruction toolkit
NASA Astrophysics Data System (ADS)
Waltenberger, Wolfgang; Mitaroff, Winfried; Moser, Fabian
2007-10-01
A detector-independent toolkit for vertex reconstruction (RAVE ) is being developed, along with a standalone framework (VERTIGO ) for testing, analyzing and debugging. The core algorithms represent state of the art for geometric vertex finding and fitting by both linear (Kalman filter) and robust estimation methods. Main design goals are ease of use, flexibility for embedding into existing software frameworks, extensibility, and openness. The implementation is based on modern object-oriented techniques, is coded in C++ with interfaces for Java and Python, and follows an open-source approach. A beta release is available. VERTIGO = "vertex reconstruction toolkit and interface to generic objects".
The RAVE/VERTIGO vertex reconstruction toolkit and framework
NASA Astrophysics Data System (ADS)
Waltenberger, W.; Mitaroff, W.; Moser, F.; Pflugfelder, B.; Riedel, H. V.
2008-07-01
A detector-independent toolkit for vertex reconstruction (RAVE1) is being developed, along with a standalone framework (VERTIGO2) for testing, analyzing and debugging. The core algorithms represent state-of-the-art for geometric vertex finding and fitting by both linear (Kalman filter) and robust estimation methods. Main design goals are ease of use, flexibility for embedding into existing software frameworks, extensibility, and openness. The implementation is based on modern object-oriented techniques, is coded in C++ with interfaces for Java and Python, and follows an open-source approach. A beta release is available.
NASA Astrophysics Data System (ADS)
Xu, Min; He, Kang-Lin; Zhang, Zi-Ping; Wang, Yi-Fang; Bian, Jian-Ming; Cao, Guo-Fu; Cao, Xue-Xiang; Chen, Shen-Jian; Deng, Zi-Yan; Fu, Cheng-Dong; Gao, Yuan-Ning; Han, Lei; Han, Shao-Qing; He, Miao; Hu, Ji-Feng; Hu, Xiao-Wei; Huang, Bin; Huang, Xing-Tao; Jia, Lu-Kui; Ji, Xiao-Bin; Li, Hai-Bo; Li, Wei-Dong; Liang, Yu-Tie; Liu, Chun-Xiu; Liu, Huai-Min; Liu, Ying; Liu, Yong; Luo, Tao; Lü, Qi-Wen; Ma, Qiu-Mei; Ma, Xiang; Mao, Ya-Jun; Mao, Ze-Pu; Mo, Xiao-Hu; Ning, Fei-Peng; Ping, Rong-Gang; Qiu, Jin-Fa; Song, Wen-Bo; Sun, Sheng-Sen; Sun, Xiao-Dong; Sun, Yong-Zhao; Tian, Hao-Lai; Wang, Ji-Ke; Wang, Liang-Liang; Wen, Shuo-Pin; Wu, Ling-Hui; Wu, Zhi; Xie, Yu-Guang; Yan, Jie; Yan, Liang; Yao, Jian; Yuan, Chang-Zheng; Yuan, Ye; Zhang, Chang-Chun; Zhang, Jian-Yong; Zhang, Lei; Zhang, Xue-Yao; Zhang, Yao; Zheng, Yang-Heng; Zhu, Yong-Sheng; Zou, Jia-Heng
2009-06-01
This paper focuses mainly on the vertex reconstruction of resonance particles with a relatively long lifetime such as K0S, Λ, as well as on lifetime measurements using a 3-dimensional fit. The kinematic constraints between the production and decay vertices and the decay vertex fitting algorithm based on the least squares method are both presented. Reconstruction efficiencies including experimental resolutions are discussed. The results and systematic errors are calculated based on a Monte Carlo simulation.
Description and performance of track and primary-vertex reconstruction with the CMS tracker
NASA Astrophysics Data System (ADS)
The CMS Collaboration
2014-10-01
A description is provided of the software algorithms developed for the CMS tracker both for reconstructing charged-particle trajectories in proton-proton interactions and for using the resulting tracks to estimate the positions of the LHC luminous region and individual primary-interaction vertices. Despite the very hostile environment at the LHC, the performance obtained with these algorithms is found to be excellent. For tbar t events under typical 2011 pileup conditions, the average track-reconstruction efficiency for promptly-produced charged particles with transverse momenta of pT > 0.9GeV is 94% for pseudorapidities of |η| < 0.9 and 85% for 0.9 < |η| < 2.5. The inefficiency is caused mainly by hadrons that undergo nuclear interactions in the tracker material. For isolated muons, the corresponding efficiencies are essentially 100%. For isolated muons of pT = 100GeV emitted at |η| < 1.4, the resolutions are approximately 2.8% in pT, and respectively, 10μm and 30μm in the transverse and longitudinal impact parameters. The position resolution achieved for reconstructed primary vertices that correspond to interesting pp collisions is 10-12μm in each of the three spatial dimensions. The tracking and vertexing software is fast and flexible, and easily adaptable to other functions, such as fast tracking for the trigger, or dedicated tracking for electrons that takes into account bremsstrahlung.
Description and performance of track and primary-vertex reconstruction with the CMS tracker
Chatrchyan, Serguei
2014-10-16
A description is provided of the software algorithms developed for the CMS tracker both for reconstructing charged-particle trajectories in proton-proton interactions and for using the resulting tracks to estimate the positions of the LHC luminous region and individual primary-interaction vertices. Despite the very hostile environment at the LHC, the performance obtained with these algorithms is found to be excellent. For tbar t events under typical 2011 pileup conditions, the average track-reconstruction efficiency for promptly-produced charged particles with transverse momenta of p_{T} > 0.9GeV is 94% for pseudorapidities of |η| < 0.9 and 85% for 0.9 < |η| < 2.5. The inefficiency is caused mainly by hadrons that undergo nuclear interactions in the tracker material. For isolated muons, the corresponding efficiencies are essentially 100%. For isolated muons of p_{T} = 100GeV emitted at |η| < 1.4, the resolutions are approximately 2.8% in p_{T}, and respectively, 10μm and 30μm in the transverse and longitudinal impact parameters. The position resolution achieved for reconstructed primary vertices that correspond to interesting pp collisions is 10–12μm in each of the three spatial dimensions. The tracking and vertexing software is fast and flexible, and easily adaptable to other functions, such as fast tracking for the trigger, or dedicated tracking for electrons that takes into account bremsstrahlung.
Description and performance of track and primary-vertex reconstruction with the CMS tracker
Chatrchyan, Serguei
2014-10-16
A description is provided of the software algorithms developed for the CMS tracker both for reconstructing charged-particle trajectories in proton-proton interactions and for using the resulting tracks to estimate the positions of the LHC luminous region and individual primary-interaction vertices. Despite the very hostile environment at the LHC, the performance obtained with these algorithms is found to be excellent. For tbar t events under typical 2011 pileup conditions, the average track-reconstruction efficiency for promptly-produced charged particles with transverse momenta of pT > 0.9GeV is 94% for pseudorapidities of |η| < 0.9 and 85% for 0.9 < |η| < 2.5. Themore » inefficiency is caused mainly by hadrons that undergo nuclear interactions in the tracker material. For isolated muons, the corresponding efficiencies are essentially 100%. For isolated muons of pT = 100GeV emitted at |η| < 1.4, the resolutions are approximately 2.8% in pT, and respectively, 10μm and 30μm in the transverse and longitudinal impact parameters. The position resolution achieved for reconstructed primary vertices that correspond to interesting pp collisions is 10–12μm in each of the three spatial dimensions. The tracking and vertexing software is fast and flexible, and easily adaptable to other functions, such as fast tracking for the trigger, or dedicated tracking for electrons that takes into account bremsstrahlung.« less
Performance of the reconstruction algorithms of the FIRST experiment pixel sensors vertex detector
NASA Astrophysics Data System (ADS)
Rescigno, R.; Finck, Ch.; Juliani, D.; Spiriti, E.; Baudot, J.; Abou-Haidar, Z.; Agodi, C.; Alvarez, M. A. G.; Aumann, T.; Battistoni, G.; Bocci, A.; Böhlen, T. T.; Boudard, A.; Brunetti, A.; Carpinelli, M.; Cirrone, G. A. P.; Cortes-Giraldo, M. A.; Cuttone, G.; De Napoli, M.; Durante, M.; Gallardo, M. I.; Golosio, B.; Iarocci, E.; Iazzi, F.; Ickert, G.; Introzzi, R.; Krimmer, J.; Kurz, N.; Labalme, M.; Leifels, Y.; Le Fevre, A.; Leray, S.; Marchetto, F.; Monaco, V.; Morone, M. C.; Oliva, P.; Paoloni, A.; Patera, V.; Piersanti, L.; Pleskac, R.; Quesada, J. M.; Randazzo, N.; Romano, F.; Rossi, D.; Rousseau, M.; Sacchi, R.; Sala, P.; Sarti, A.; Scheidenberger, C.; Schuy, C.; Sciubba, A.; Sfienti, C.; Simon, H.; Sipala, V.; Tropea, S.; Vanstalle, M.; Younis, H.
2014-12-01
Hadrontherapy treatments use charged particles (e.g. protons and carbon ions) to treat tumors. During a therapeutic treatment with carbon ions, the beam undergoes nuclear fragmentation processes giving rise to significant yields of secondary charged particles. An accurate prediction of these production rates is necessary to estimate precisely the dose deposited into the tumours and the surrounding healthy tissues. Nowadays, a limited set of double differential carbon fragmentation cross-section is available. Experimental data are necessary to benchmark Monte Carlo simulations for their use in hadrontherapy. The purpose of the FIRST experiment is to study nuclear fragmentation processes of ions with kinetic energy in the range from 100 to 1000 MeV/u. Tracks are reconstructed using information from a pixel silicon detector based on the CMOS technology. The performances achieved using this device for hadrontherapy purpose are discussed. For each reconstruction step (clustering, tracking and vertexing), different methods are implemented. The algorithm performances and the accuracy on reconstructed observables are evaluated on the basis of simulated and experimental data.
NASA Astrophysics Data System (ADS)
Merzlaya, Anastasia;
2017-01-01
The heavy-ion programme of the NA61/SHINE experiment at CERN SPS is expanding to allow precise measurements of exotic particles with lifetime few hundred microns. A Vertex Detector for open charm measurements at the SPS is being constructed by the NA61/SHINE Collaboration to meet the challenges of high spatial resolution of secondary vertices and efficiency of track registration. This task is solved by the application of the coordinate sensitive CMOS Monolithic Active Pixel Sensors with extremely low material budget in the new Vertex Detector. A small-acceptance version of the Vertex Detector is being tested this year, later it will be expanded to a large-acceptance version. Simulation studies will be presented. A method of track reconstruction in the inhomogeneous magnetic field for the Vertex Detector was developed and implemented. Numerical calculations show the possibility of high precision measurements in heavy ion collisions of strange and multi strange particles, as well as heavy flavours, like charmed particles.
Strube, Jan; Graf, Norman; /SLAC
2006-03-03
This document describes the implementation of the topological vertex finding algorithm ZVTOP within the org.lcsim reconstruction and analysis framework. At the present date, Java vertexing tools allow users to perform topological vertexing on tracks that have been obtained from a Fast MC simulation. An implementation that will be able to handle fully reconstructed events is being designed from the ground up for longevity and maintainability.
Lim, Chi Wan; Su, Yi; Yeo, Si Yong; Ng, Gillian Maria; Nguyen, Vinh Tan; Zhong, Liang; Tan, Ru San; Poh, Kian Keong; Chai, Ping
2014-01-01
We propose an automatic algorithm for the reconstruction of patient-specific cardiac mesh models with 1-to-1 vertex correspondence. In this framework, a series of 3D meshes depicting the endocardial surface of the heart at each time step is constructed, based on a set of border delineated magnetic resonance imaging (MRI) data of the whole cardiac cycle. The key contribution in this work involves a novel reconstruction technique to generate a 4D (i.e., spatial–temporal) model of the heart with 1-to-1 vertex mapping throughout the time frames. The reconstructed 3D model from the first time step is used as a base template model and then deformed to fit the segmented contours from the subsequent time steps. A method to determine a tree-based connectivity relationship is proposed to ensure robust mapping during mesh deformation. The novel feature is the ability to handle intra- and inter-frame 2D topology changes of the contours, which manifests as a series of merging and splitting of contours when the images are viewed either in a spatial or temporal sequence. Our algorithm has been tested on five acquisitions of cardiac MRI and can successfully reconstruct the full 4D heart model in around 30 minutes per subject. The generated 4D heart model conforms very well with the input segmented contours and the mesh element shape is of reasonably good quality. The work is important in the support of downstream computational simulation activities. PMID:24743555
Salyer, K E; Gendler, E; Squier, C A
1997-05-01
The successful use of cortical demineralized perforated bone in the treatment of extensive skeletal defects in children is exemplified by this case involving Siamese twins joined at the skull vertex. Four years following extensive skull reconstruction using demineralized perforated bone, an examination revealed successful calvarial reconstruction in one twin. The other twin required additional implants of demineralized perforated bone to fill in defects. However, a histologic examination taken following this additional procedure revealed that these implants neither caused tissue reaction over a 4-year period, nor showed signs of resorption. Bony remodeling and new bone formation were in progress. Compared with other bone substitutes, demineralized perforated bone has proven to be effective in the treatment of large skull defects in children.
Lueth, V.
1992-07-01
The purpose of a vertex detector is to measure position and angles of charged particle tracks to sufficient precision so as to be able to separate tracks originating from decay vertices from those produced at the interaction vertex. Such measurements are interesting because they permit the detection of weakly decaying particles with lifetimes down to 10{sup {minus}13} s, among them the {tau} lepton and charm and beauty hadrons. These two lectures are intended to introduce the reader to the different techniques for the detection of secondary vertices that have been developed over the past decades. The first lecture includes a brief introduction to the methods used to detect secondary vertices and to estimate particle lifetimes. It describes the traditional technologies, based on photographic recording in emulsions and on film of bubble chambers, and introduces fast electronic registration of signals derived from scintillating fibers, drift chambers and gaseous micro-strip chambers. The second lecture is devoted to solid state detectors. It begins with a brief introduction into semiconductor devices, and then describes the application of large arrays of strip and pixel diodes for charged particle tracking. These lectures can only serve as an introduction the topic of vertex detectors. Time and space do not allow for an in-depth coverage of many of the interesting aspects of vertex detector design and operation.
Khachatryan, Vardan; et al.
2011-03-01
A measurement of the angular correlations between beauty and anti-beauty hadrons (B B-bar) produced in pp collisions at a centre-of-mass energy of 7 TeV at the CERN LHC is presented, probing for the first time the region of small angular separation. The B hadrons are identified by the presence of displaced secondary vertices from their decays. The B hadron angular separation is reconstructed from the decay vertices and the primary-interaction vertex. The differential B B-bar production cross section, measured from a data sample collected by CMS and corresponding to an integrated luminosity of 3.1 inverse picobarns, shows that a sizable fraction of the B B-bar pairs are produced with small opening angles. These studies provide a test of QCD and further insight into the dynamics of b b-bar production.
Belle II Silicon Vertex Detector
NASA Astrophysics Data System (ADS)
Dutta, D.; Adamczyk, K.; Aihara, H.; Angelini, C.; Aziz, T.; Babu, V.; Bacher, S.; Bahinipati, S.; Barberio, E.; Baroncelli, Ti.; Baroncelli, To.; Basith, A. K.; Batignani, G.; Bauer, A.; Behera, P. K.; Bergauer, T.; Bettarini, S.; Bhuyan, B.; Bilka, T.; Bosi, F.; Bosisio, L.; Bozek, A.; Buchsteiner, F.; Bulla, L.; Caria, G.; Casarosa, G.; Ceccanti, M.; Červenkov, D.; Chendvankar, S. R.; Dash, N.; De Pietro, G.; Divekar, S. T.; Doležal, Z.; Forti, F.; Friedl, M.; Hara, K.; Higuchi, T.; Horiguchi, T.; Irmler, C.; Ishikawa, A.; Jeon, H. B.; Joo, C.; Kandra, J.; Kambara, N.; Kang, K. H.; Kawasaki, T.; Kodyš, P.; Kohriki, T.; Koike, S.; Kolwalkar, M. M.; Kumar, R.; Kun, W.; Kvasnička, P.; La Licata, C.; Lanceri, L.; Lettenbicher, J.; Libby, J.; Lueck, T.; Maki, M.; Mammini, P.; Mayekar, S. N.; Mohanty, G. B.; Mohanty, S.; Morii, T.; Nakamura, K. R.; Natkaniec, Z.; Onuki, Y.; Ostrowicz, W.; Paladino, A.; Paoloni, E.; Park, H.; Pilo, F.; Profeti, A.; Rashevskaya, I.; Rao, K. K.; Rizzo, G.; Resmi, P. K.; Rozanska, M.; Sasaki, J.; Sato, N.; Schultschik, S.; Schwanda, C.; Seino, Y.; Shimizu, N.; Stypula, J.; Suzuki, J.; Tanaka, S.; Taylor, G. N.; Thalmeier, R.; Thomas, R.; Tsuboyama, T.; Uozumi, S.; Urquijo, P.; Vitale, L.; Watanuki, S.; Watanabe, M.; Watson, I. J.; Webb, J.; Wiechczynski, J.; Williams, S.; Würkner, B.; Yamamoto, H.; Yin, H.; Yoshinobu, T.; Zani, L.
2017-02-01
The Belle II experiment at the SuperKEKB asymmetric energy e+e‑ collider in KEK, Japan will operate at an instantaneous luminosity 40 times larger than that of its predecessor, Belle. It is built with an aim of collecting a huge amount of data (50 ab‑1 by 2025) for precise CP violation measurements and new physics search. Thus, we need an accurate vertex determination and reconstruction of low momentum tracks which will be achieved with the help of vertex detector (VXD). The Belle II VXD consists of two layers of DEPFET pixels (`Pixel Detector') and four layers of double-sided silicon microstrip sensors (`Silicon Vertex Detector'), assembled over carbon fibre ribs. In this paper, we discuss about the Belle II Silicon Vertex Detector, especially its design and key features; we also present its module (`ladder') assembly and testing procedures.
The CDF silicon vertex trigger
B. Ashmanskas; A. Barchiesi; A. Bardi
2003-06-23
The CDF experiment's Silicon Vertex Trigger is a system of 150 custom 9U VME boards that reconstructs axial tracks in the CDF silicon strip detector in a 15 {mu}sec pipeline. SVT's 35 {mu}m impact parameter resolution enables CDF's Level 2 trigger to distinguish primary and secondary particles, and hence to collect large samples of hadronic bottom and charm decays. We review some of SVT's key design features. Speed is achieved with custom VLSI pattern recognition, linearized track fitting, pipelining, and parallel processing. Testing and reliability are aided by built-in logic state analysis and test-data sourcing at each board's input and output, a common inter-board data link, and a universal ''Merger'' board for data fan-in/fan-out. Speed and adaptability are enhanced by use of modern FPGAs.
Vertex Detector Cable Considerations
Cooper, William E.; /Fermilab
2009-02-01
Vertex detector cable requirements are considered within the context of the SiD concept. Cable material should be limited so that the number of radiation lengths represented is consistent with the material budget. In order to take advantage of the proposed accelerator beam structure and allow cooling by flow of dry gas, 'pulsed power' is assumed. Potential approaches to power distribution, cable paths, and cable design for operation in a 5 T magnetic field are described.
Biricodar. Vertex Pharmaceuticals.
Dey, Saibal
2002-05-01
Vertex is developing biricodar as a chemosensitizing agent designed to restore the effectiveness of chemotherapeutic agents in tumor multidrug resistance. By November 1998, phase II trials had commenced for biricodar, in combination with chemotherapy, for five common cancer indications: breast, ovarian, soft-tissue sarcomas, small cell lung cancer and prostate cancer. Phase II trials were ongoing in January 2002. By March 2000, Vertex was the sole developer of biricodar, as an agreement made in 1996 with BioChem Pharma (now Shire Pharmaceuticals), for the development and marketing of biricodar in Canada was terminated. Biricodar is the free base compound, which also has a citrate salt analog known as VX-710-3. Vertex has published three patents, WO-09615101, WO-09636630 and WO-09736869, disclosing derivatives of biricodar that are claimed for the treatment of multidrug resistant protein and P-glycoprotein-mediated multidrug resistant tumors. In January 2002, a Banc of America analyst report forecast that biricodar had a 30% chance of reaching the market with a launch date in the second half of 2005, with peak sales estimated at $250 million.
On Making a Distinguished Vertex Minimum Degree by Vertex Deletion
NASA Astrophysics Data System (ADS)
Betzler, Nadja; Bredereck, Robert; Niedermeier, Rolf; Uhlmann, Johannes
For directed and undirected graphs, we study the problem to make a distinguished vertex the unique minimum-(in)degree vertex through deletion of a minimum number of vertices. The corresponding NP-hard optimization problems are motivated by applications concerning control in elections and social network analysis. Continuing previous work for the directed case, we show that the problem is W[2]-hard when parameterized by the graph's feedback arc set number, whereas it becomes fixed-parameter tractable when combining the parameters "feedback vertex set number" and "number of vertices to delete". For the so far unstudied undirected case, we show that the problem is NP-hard and W[1]-hard when parameterized by the "number of vertices to delete". On the positive side, we show fixed-parameter tractability for several parameterizations measuring tree-likeness, including a vertex-linear problem kernel with respect to the parameter "feedback edge set number". On the contrary, we show a non-existence result concerning polynomial-size problem kernels for the combined parameter "vertex cover number and number of vertices to delete", implying corresponding nonexistence results when replacing vertex cover number by treewidth or feedback vertex set number.
SVT: an online silicon vertex tracker for the CDF upgrade
Bardi, A.; Belforte, S.; Berryhill, J.; CDF Collaboration
1997-07-01
The SVT is an online tracker for the CDF upgrade which will reconstruct 2D tracks using information from the Silicon VerteX detector (SVXII) and Central Outer Tracker (COT). The precision measurement of the track impact parameter will then be used to select and record large samples of B hadrons. We discuss the overall architecture, algorithms, and hardware implementation of the system.
The STAR Vertex Position Detector
NASA Astrophysics Data System (ADS)
Llope, W. J.; Zhou, J.; Nussbaum, T.; Hoffmann, G. W.; Asselta, K.; Brandenburg, J. D.; Butterworth, J.; Camarda, T.; Christie, W.; Crawford, H. J.; Dong, X.; Engelage, J.; Eppley, G.; Geurts, F.; Hammond, J.; Judd, E.; McDonald, D. L.; Perkins, C.; Ruan, L.; Scheblein, J.; Schambach, J. J.; Soja, R.; Xin, K.; Yang, C.
2014-09-01
The 2×3 channel pseudo Vertex Position Detector (pVPD) in the STAR experiment at RHIC has been upgraded to a 2×19 channel detector in the same acceptance, called the Vertex Position Detector (VPD). This detector is fully integrated into the STAR trigger system and provides the primary input to the minimum-bias trigger in Au+Au collisions. The information from the detector is used both in the STAR Level-0 trigger and offline to measure the location of the primary collision vertex along the beam pipe and the event "start time" needed by other fast-timing detectors in STAR. The offline timing resolution of single detector channels in full-energy Au+Au collisions is ~100 ps, resulting in a start time resolution of a few tens of picoseconds and a resolution on the primary vertex location of ~1 cm.
Ab initio dynamical vertex approximation
NASA Astrophysics Data System (ADS)
Galler, Anna; Thunström, Patrik; Gunacker, Patrik; Tomczak, Jan M.; Held, Karsten
2017-03-01
Diagrammatic extensions of dynamical mean-field theory (DMFT) such as the dynamical vertex approximation (DΓ A) allow us to include nonlocal correlations beyond DMFT on all length scales and proved their worth for model calculations. Here, we develop and implement an Ab initio DΓ A approach (AbinitioDΓ A ) for electronic structure calculations of materials. The starting point is the two-particle irreducible vertex in the two particle-hole channels which is approximated by the bare nonlocal Coulomb interaction and all local vertex corrections. From this, we calculate the full nonlocal vertex and the nonlocal self-energy through the Bethe-Salpeter equation. The AbinitioDΓ A approach naturally generates all local DMFT correlations and all nonlocal G W contributions, but also further nonlocal correlations beyond: mixed terms of the former two and nonlocal spin fluctuations. We apply this new methodology to the prototypical correlated metal SrVO3.
The Belle II Silicon Vertex Detector
NASA Astrophysics Data System (ADS)
Friedl, M.; Ackermann, K.; Aihara, H.; Aziz, T.; Bergauer, T.; Bozek, A.; Campbell, A.; Dingfelder, J.; Drasal, Z.; Frankenberger, A.; Gadow, K.; Gfall, I.; Haba, J.; Hara, K.; Hara, T.; Higuchi, T.; Himori, S.; Irmler, C.; Ishikawa, A.; Joo, C.; Kah, D. H.; Kang, K. H.; Kato, E.; Kiesling, C.; Kodys, P.; Kohriki, T.; Koike, S.; Kvasnicka, P.; Marinas, C.; Mayekar, S. N.; Mibe, T.; Mohanty, G. B.; Moll, A.; Negishi, K.; Nakayama, H.; Natkaniec, Z.; Niebuhr, C.; Onuki, Y.; Ostrowicz, W.; Park, H.; Rao, K. K.; Ritter, M.; Rozanska, M.; Saito, T.; Sakai, K.; Sato, N.; Schmid, S.; Schnell, M.; Shimizu, N.; Steininger, H.; Tanaka, S.; Tanida, K.; Taylor, G.; Tsuboyama, T.; Ueno, K.; Uozumi, S.; Ushiroda, Y.; Valentan, M.; Yamamoto, H.
2013-12-01
The KEKB machine and the Belle experiment in Tsukuba (Japan) are now undergoing an upgrade, leading to an ultimate luminosity of 8×1035 cm-2 s-1 in order to measure rare decays in the B system with high statistics. The previous vertex detector cannot cope with this 40-fold increase of luminosity and thus needs to be replaced. Belle II will be equipped with a two-layer Pixel Detector surrounding the beam pipe, and four layers of double-sided silicon strip sensors at higher radii than the old detector. The Silicon Vertex Detector (SVD) will have a total sensitive area of 1.13 m2 and 223,744 channels-twice as many as its predecessor. All silicon sensors will be made from 150 mm wafers in order to maximize their size and thus to reduce the relative contribution of the support structure. The forward part has slanted sensors of trapezoidal shape to improve the measurement precision and to minimize the amount of material as seen by particles from the vertex. Fast-shaping front-end amplifiers will be used in conjunction with an online hit time reconstruction algorithm in order to reduce the occupancy to the level of a few percent at most. A novel “Origami” chip-on-sensor scheme is used to minimize both the distance between strips and amplifier (thus reducing the electronic noise) as well as the overall material budget. This report gives an overview on the status of the Belle II SVD and its components, including sensors, front-end detector ladders, mechanics, cooling and the readout electronics.
A neural network z-vertex trigger for Belle II
NASA Astrophysics Data System (ADS)
Neuhaus, S.; Skambraks, S.; Abudinen, F.; Chen, Y.; Feindt, M.; Frühwirth, R.; Heck, M.; Kiesling, C.; Knoll, A.; Paul, S.; Schieck, J.
2015-05-01
We present the concept of a track trigger for the Belle II experiment, based on a neural network approach, that is able to reconstruct the z (longitudinal) position of the event vertex within the latency of the first level trigger. The trigger will thus be able to suppress a large fraction of the dominating background from events outside of the interaction region. The trigger uses the drift time information of the hits from the Central Drift Chamber (CDC) of Belle II within narrow cones in polar and azimuthal angle as well as in transverse momentum (sectors), and estimates the z-vertex without explicit track reconstruction. The preprocessing for the track trigger is based on the track information provided by the standard CDC trigger. It takes input from the 2D (r — φ) track finder, adds information from the stereo wires of the CDC, and finds the appropriate sectors in the CDC for each track in a given event. Within each sector, the z-vertex of the associated track is estimated by a specialized neural network, with a continuous output corresponding to the scaled z-vertex. The input values for the neural network are calculated from the wire hits of the CDC.
Performance of the CDF Online Silicon Vertex Tracker
R. Carosi et al.
2002-03-27
The Online Silicon Vertex Tracker (SVT) is the new trigger processor dedicated to the 2-D reconstruction of charged particle trajectories at the Level 2 of the CDF trigger. The SVT links the digitized pulse heights found within the Silicon Vertex detector to the tracks reconstructed in the Central Outer Tracker by the Level 1 fast track finder. Preliminary tests of the system took place during the October 2000 commissioning run of the Tevatron Collider. During the April-October 2001 data taking it was possible to evaluate the performance of the system. In this paper we review the tracking algorithms implemented in the SVT and we report on the performance achieved during the early phase of run II.
Vertex Models of Epithelial Morphogenesis
Fletcher, Alexander G.; Osterfield, Miriam; Baker, Ruth E.; Shvartsman, Stanislav Y.
2014-01-01
The dynamic behavior of epithelial cell sheets plays a central role during numerous developmental processes. Genetic and imaging studies of epithelial morphogenesis in a wide range of organisms have led to increasingly detailed mechanisms of cell sheet dynamics. Computational models offer a useful means by which to investigate and test these mechanisms, and have played a key role in the study of cell-cell interactions. A variety of modeling approaches can be used to simulate the balance of forces within an epithelial sheet. Vertex models are a class of such models that consider cells as individual objects, approximated by two-dimensional polygons representing cellular interfaces, in which each vertex moves in response to forces due to growth, interfacial tension, and pressure within each cell. Vertex models are used to study cellular processes within epithelia, including cell motility, adhesion, mitosis, and delamination. This review summarizes how vertex models have been used to provide insight into developmental processes and highlights current challenges in this area, including progressing these models from two to three dimensions and developing new tools for model validation. PMID:24896108
NASA Astrophysics Data System (ADS)
Gornushkin, Yu. A.; Dmitrievsky, S. G.; Chukanov, A. V.
2015-01-01
The OPERA experiment is designed for the direct observation of the appearance of ντ from νμ → ντ oscillation in a νμ beam. A description of the procedure of neutrino interaction vertex localization (Brick Finding) by electronic detectors of a hybrid OPERA setup is presented. The procedure includes muon track and hadronic shower axis reconstruction and a determination of the target bricks with the highest probability to contain the vertex.
A Novel Vertex Affinity for Community Detection
Yoo, Andy; Sanders, Geoffrey; Henson, Van; Vassilevski, Panayot
2015-10-05
We propose a novel vertex affinity measure in this paper. The new vertex affinity quantifies the proximity between two vertices in terms of their clustering strength and is ideal for such graph analytics applications as community detection. We also developed a framework that combines simple graph searches and resistance circuit formulas to compute the vertex affinity efficiently. We study the properties of the new affinity measure empirically in comparison to those of other popular vertex proximity metrics. Our results show that the existing metrics are ill-suited for community detection due to their lack of fundamental properties that are essential for correctly capturing inter- and intra-cluster vertex proximity.
Belle II silicon vertex detector
NASA Astrophysics Data System (ADS)
Adamczyk, K.; Aihara, H.; Angelini, C.; Aziz, T.; Babu, V.; Bacher, S.; Bahinipati, S.; Barberio, E.; Baroncelli, Ti.; Baroncelli, To.; Basith, A. K.; Batignani, G.; Bauer, A.; Behera, P. K.; Bergauer, T.; Bettarini, S.; Bhuyan, B.; Bilka, T.; Bosi, F.; Bosisio, L.; Bozek, A.; Buchsteiner, F.; Casarosa, G.; Ceccanti, M.; Červenkov, D.; Chendvankar, S. R.; Dash, N.; Divekar, S. T.; Doležal, Z.; Dutta, D.; Enami, K.; Forti, F.; Friedl, M.; Hara, K.; Higuchi, T.; Horiguchi, T.; Irmler, C.; Ishikawa, A.; Jeon, H. B.; Joo, C. W.; Kandra, J.; Kang, K. H.; Kato, E.; Kawasaki, T.; Kodyš, P.; Kohriki, T.; Koike, S.; Kolwalkar, M. M.; Kvasnička, P.; Lanceri, L.; Lettenbicher, J.; Maki, M.; Mammini, P.; Mayekar, S. N.; Mohanty, G. B.; Mohanty, S.; Morii, T.; Nakamura, K. R.; Natkaniec, Z.; Negishi, K.; Nisar, N. K.; Onuki, Y.; Ostrowicz, W.; Paladino, A.; Paoloni, E.; Park, H.; Pilo, F.; Profeti, A.; Rashevskaya, I.; Rao, K. K.; Rizzo, G.; Rozanska, M.; Sandilya, S.; Sasaki, J.; Sato, N.; Schultschik, S.; Schwanda, C.; Seino, Y.; Shimizu, N.; Stypula, J.; Suzuki, J.; Tanaka, S.; Tanida, K.; Taylor, G. N.; Thalmeier, R.; Thomas, R.; Tsuboyama, T.; Uozumi, S.; Urquijo, P.; Vitale, L.; Volpi, M.; Watanuki, S.; Watson, I. J.; Webb, J.; Wiechczynski, J.; Williams, S.; Würkner, B.; Yamamoto, H.; Yin, H.; Yoshinobu, T.
2016-09-01
The Belle II experiment at the SuperKEKB collider in Japan is designed to indirectly probe new physics using approximately 50 times the data recorded by its predecessor. An accurate determination of the decay-point position of subatomic particles such as beauty and charm hadrons as well as a precise measurement of low-momentum charged particles will play a key role in this pursuit. These will be accomplished by an inner tracking device comprising two layers of pixelated silicon detector and four layers of silicon vertex detector based on double-sided microstrip sensors. We describe herein the design, prototyping and construction efforts of the Belle-II silicon vertex detector.
STAR Vertex Detector Upgrade Development
Greiner, Leo C.; Matis, Howard S.; Stezelberger, Thorsten; Vu,Chinh Q.; Wieman, Howard; Szelezniak, Michal; Sun, Xiangming
2008-01-28
We report on the development and prototyping efforts undertaken with the goal of producing a micro-vertex detector for the STAR experiment at the RHIC accelerator at BNL. We present the basic detector requirements and show a sensor development path, conceptual mechanical design candidates and readout architecture. Prototyping and beam test results with current generation MimoSTAR-2 sensors and a readout system featuring FPGA based on-the-fly hit finding and data sparsification are also presented.
Refining the shifted topological vertex
Drissi, L. B.; Jehjouh, H.; Saidi, E. H.
2009-01-15
We study aspects of the refining and shifting properties of the 3d MacMahon function C{sub 3}(q) used in topological string theory and BKP hierarchy. We derive the explicit expressions of the shifted topological vertex S{sub {lambda}}{sub {mu}}{sub {nu}}(q) and its refined version T{sub {lambda}}{sub {mu}}{sub {nu}}(q,t). These vertices complete results in literature.
Imaging the LHC beams with silicon and scintillating fibre vertex detectors
NASA Astrophysics Data System (ADS)
Rihl, M.
2017-02-01
The LHCb Vertex Locator (VELO) is used to reconstruct beam-gas interaction vertices which allows one to obtain precise profiles of the LHC beams. In LHCb, this information is combined with the profile of the reconstructed beam-beam collisions and with the LHC beam currents to perform precise measurements of the luminosity. This beam-gas imaging (BGI) method also allows one to study the transverse beam shapes, beam positions and angles in real time. Therefore, a demonstrator beam-gas vertex detector (BGV) based on scintillating fibre modules has been built and installed in LHC Ring 2 at point 4.
Spinfoam Cosmology with the Proper Vertex
NASA Astrophysics Data System (ADS)
Vilensky, Ilya
2017-01-01
A modification of the EPRL vertex amplitude in the spin-foam framework of quantum gravity - so-called ``proper vertex amplitude'' - has been developed to enable correct semi-classical behavior to conform to the classical Regge calculus. The proper vertex amplitude is defined by projecting to the single gravitational sector. The amplitude is recast into an exponentiated form and we derive the asymptotic form of the projector part of the action. This enables us to study the asymptotics of the proper vertex by applying extended stationary phase methods. We use the proper vertex amplitude to investigate transition amplitudes between coherent quantum boundary states of cosmological geometries. In particular, Hartle-Hawking no-boundary states are computed in the proper vertex framework. We confirm that in the classical limit the Hartle-Hawking wavefunction satisfies the Hamiltonian constraint. Partly supported by NSF grants PHY-1205968 and PHY-1505490.
NASA Astrophysics Data System (ADS)
Alipour Tehrani, Niloufar
2016-07-01
A vertex detector concept is under development for the proposed multi-TeV linear e+e- Compact Linear Collider (CLIC). To perform precision physics measurements in a challenging environment, the CLIC vertex detector pushes the technological requirements to the limits. This paper reviews the requirements for the CLIC vertex detector and gives an overview of recent R&D achievements in the domains of sensor, readout, powering and cooling.
The CDF Silicon Vertex Detector
Tkaczyk, S.; Carter, H.; Flaugher, B.
1993-09-01
A silicon strip vertex detector was designed, constructed and commissioned at the CDF experiment at the Tevatron collider at Fermilab. The mechanical design of the detector, its cooling and monitoring are presented. The front end electronics employing a custom VLSI chip, the readout electronics and various components of the SVX system are described. The system performance and the experience with the operation of the detector in the radiation environment are discussed. The device has been taking colliding beams data since May of 1992, performing at its best design specifications and enhancing the physics program of CDF.
Vertex finding with deformable templates at LHC
NASA Astrophysics Data System (ADS)
Stepanov, Nikita; Khanov, Alexandre
1997-02-01
We present a novel vertex finding technique. The task is formulated as a discrete-continuous optimisation problem in a way similar to the deformable templates approach for the track finding. Unlike the track finding problem, "elastic hedgehogs" rather than elastic arms are used as deformable templates. They are initialised by a set of procedures which provide zero level approximation for vertex positions and track parameters at the vertex point. The algorithm was evaluated using the simulated events for the LHC CMS detector and demonstrated good performance.
Lorentzian proper vertex amplitude: Asymptotics
NASA Astrophysics Data System (ADS)
Engle, Jonathan; Vilensky, Ilya; Zipfel, Antonia
2016-09-01
In previous work, the Lorentzian proper vertex amplitude for a spin-foam model of quantum gravity was derived. In the present work, the asymptotics of this amplitude are studied in the semiclassical limit. The starting point of the analysis is an expression for the amplitude as an action integral with action differing from that in the Engle-Pereira-Rovelli-Livine (EPRL) case by an extra "projector" term. This extra term scales linearly with spins only in the asymptotic limit, and is discontinuous on a (lower dimensional) submanifold of the integration domain in the sense that its value at each such point depends on the direction of approach. New tools are introduced to generalize stationary phase methods to this case. For the case of boundary data which can be glued to a nondegenerate Lorentzian 4-simplex, the asymptotic limit of the amplitude is shown to equal the single Feynman term, showing that the extra term in the asymptotics of the EPRL amplitude has been eliminated.
First experience and results from the HERA-/B vertex detector system
NASA Astrophysics Data System (ADS)
Bauer, C.; Baumann, I.; Bräuer, M.; Eberle, M.; Fallot-Burghardt, W.; Grigoriev, E.; Hofmann, W.; Hüpper, A.; Klefenz, F.; Knöpfle, K. T.; Leffers, G.; Perschke, T.; Rieling, J.; Schmelling, M.; Schwingenheuer, B.; Sexauer, E.; Seybold, L.; Spengler, J.; StDenis, R.; Trunk, U.; Wanke, R.; Abt, I.; Fox, H.; Moshous, B.; Riechmann, K.; Rietz, M.; Ruebsam, R.; Wagner, W.
1998-11-01
The HERA- B collaboration is building a detector to realize the ambitious goal of observing CP violation in decays of neutral B-mesons. A central element of the apparatus is the silicon vertex detector used to selectively trigger on these decays in a high charged particle multiplicity background environment and to reconstruct secondary vertices from such decays with high precision. The vertex detector, the supporting infrastructure and first results using prototype detectors are described. Results include imaging of the proton interaction region on the HERA- B target, hit distributions in the detector planes, and alignment of the detectors with each other and the target.
Upgrade of the LHCb Vertex Locator
NASA Astrophysics Data System (ADS)
Leflat, A.
2014-08-01
The upgrade of the LHCb experiment, planned for 2018, will transform the entire readout to a trigger-less system operating at 40 MHz. All data reduction algorithms will be executed in a high-level software farm, with access to all event information. This will enable the detector to run at luminosities of 1-2 × 1033/cm2/s and probe physics beyond the Standard Model in the heavy sector with unprecedented precision. The upgraded VELO must be low mass, radiation hard and vacuum compatible. It must be capable of fast pattern recognition and track reconstruction and will be required to drive data to the outside world at speeds of up to 2.5 Tbit/s. This challenge is being met with a new Vertex Locator (VELO) design based on hybrid pixel detectors positioned to within 5 mm of the LHC colliding beams. The sensors have 55 × 55 μm square pixels and the VELOPix ASIC which is being developed for the readout is based on the Timepix/Medipix family of chips. The hottest ASIC will have to cope with pixel hit rates of up to 900 MHz. The material budget will be optimised with the use of evaporative CO2 coolant circulating in microchannels within a thin silicon substrate. Microchannel cooling brings many advantages: very efficient heat transfer with almost no temperature gradients across the module, no CTE mismatch with silicon components, and low material contribution. This is a breakthrough technology being developed for LHCb. LHCb is also focussing effort on the construction of a lightweight foil to separate the primary and secondary LHC vacua, the development of high speed cables and radiation qualification of the module. The 40 MHz readout will also bring significant conceptual changes to the way in which the upgrade trigger is operated. Work is in progress to incorporate momentum and impact parameter information into the trigger at the earliest possible stage, using the fast pattern recognition capabilities of the upgraded detector. The current status of the VELO upgrade will
The silicon vertex detector of HERA-B
Moshous, Basil
1998-02-01
HERA-B is an experiment to study CP violation in the B system using an internal target at the DESY HERA proton ring(820 GeV). The main goal is to measure the asymmetry in the 'gold plated' decays of B{sup 0}, B-bar{sup 0}{yields}J/{psi}K{sub s}{sup 0} yielding a measurement of the angle {beta} of the unitarity triangle. From the semileptonic decay channels of the b, b-bar-hadron produced in association with the B{sup 0},B-bar{sup 0} can be used to tag the flavor of the B{sup 0}. The purpose of the Vertex Detector System is to provide the track coordinates for reconstructing the J/{psi}{yields}e{sup +}e{sup -}, {mu}{sup +}{mu}{sup -} secondary decay vertices and the impact parameters of all tagging particles.
Lifetime tests for MAC vertex chamber
Nelson, H.N.
1986-07-01
A vertex chamber for MAC was proposed to increase precision in the measurement of the B hadron and tau lepton lifetimes. Thin-walled aluminized mylar drift tubes were used for detector elements. A study of radiation hardness was conducted under the conditions of the proposed design using different gases and different operating conditions. (LEW)
Battaglia, Marco; Bussat, Jean-Marie; Contarato, Devis; Denes,Peter; Glesener, Lindsay; Greiner, Leo; Hooberman, Benjamin; Shuman,Derek; Tompkins, Lauren; Vu, Chinh; Bisello, Dario; Giubilato, Piero; Pantano, Devis; Costa, Marco; La Rosa, Alessandro; Bolla, Gino; Bortoletto, Daniela; Children, Isaac
2007-10-01
This document summarizes past achievements, current activities and future goals of the R&D program aimed at the design, prototyping and characterization of a full detector module, equipped with monolithic pixel sensors, matching the requirements for the Vertex Tracker at the ILC. We provide a plan of activities to obtain a demonstrator multi-layered vertex tracker equipped with sensors matching the ILC requirements and realistic lightweight ladders in FY11, under the assumption that ILC detector proto-collaborations will be choosing technologies and designs for the Vertex Tracker by that time. The R&D program discussed here started at LBNL in 2004, supported by a Laboratory Directed R&D (LDRD) grant and by funding allocated from the core budget of the LBNL Physics Division and from the Department of Physics at UC Berkeley. Subsequently additional funding has been awarded under the NSF-DOE LCRD program and also personnel have become available through collaborative research with other groups. The aim of the R&D program carried out by our collaboration is to provide a well-integrated, inclusive research effort starting from physics requirements for the ILC Vertex Tracker and addressing Si sensor design and characterization, engineered ladder design, module system issues, tracking and vertex performances and beam test validation. The broad scope of this program is made possible by important synergies with existing know-how and concurrent programs both at LBNL and at the other collaborating institutions. In particular, significant overlaps with LHC detector design, SLHC R&D as well as prototyping for the STAR upgrade have been exploited to optimize the cost per deliverable of our program. This activity is carried out as a collaborative effort together with Accelerator and Fusion Research, the Engineering and the Nuclear Science Divisions at LBNL, INFN and the Department of Physics in Padova, Italy, INFN and the Department of Physics in Torino, Italy and the Department
Optimized Vertex Method and Hybrid Reliability
NASA Technical Reports Server (NTRS)
Smith, Steven A.; Krishnamurthy, T.; Mason, B. H.
2002-01-01
A method of calculating the fuzzy response of a system is presented. This method, called the Optimized Vertex Method (OVM), is based upon the vertex method but requires considerably fewer function evaluations. The method is demonstrated by calculating the response membership function of strain-energy release rate for a bonded joint with a crack. The possibility of failure of the bonded joint was determined over a range of loads. After completing the possibilistic analysis, the possibilistic (fuzzy) membership functions were transformed to probability density functions and the probability of failure of the bonded joint was calculated. This approach is called a possibility-based hybrid reliability assessment. The possibility and probability of failure are presented and compared to a Monte Carlo Simulation (MCS) of the bonded joint.
The HERA-B vertex detector system
NASA Astrophysics Data System (ADS)
Bauer, C.; Bräuer, M.; Glebe, T.; Hofmann, W.; Jagla, T.; Klefenz, F.; Knöpfle, K. T.; Pugatch, V.; Schmelling, M.; Schwingenheuer, B.; Sexauer, E.; Trunk, U.; Wanke, R.; Zurheide, F.; Abt, I.; Dressel, M.; Kisel, I.; Masciocchi, S.; Moshous, B.; Perschke, T.; Sang, M.; Schaller, S.; Wagner, W.
2000-10-01
The HERA-B experiment is being built to measure CP violation in the B-system using internal targets at the HERA proton storage ring at DESY. This paper presents an overview of its vertex detector which - apart from an additional superlayer - is realized by a system of 20 Roman pots containing seven superlayers of double-sided silicon microstrip detectors that are operated at 10 mm distance from the proton beam in a high-radiation environment.
Complex growing networks with intrinsic vertex fitness
Bedogne, C.; Rodgers, G. J.
2006-10-15
One of the major questions in complex network research is to identify the range of mechanisms by which a complex network can self organize into a scale-free state. In this paper we investigate the interplay between a fitness linking mechanism and both random and preferential attachment. In our models, each vertex is assigned a fitness x, drawn from a probability distribution {rho}(x). In Model A, at each time step a vertex is added and joined to an existing vertex, selected at random, with probability p and an edge is introduced between vertices with fitnesses x and y, with a rate f(x,y), with probability 1-p. Model B differs from Model A in that, with probability p, edges are added with preferential attachment rather than randomly. The analysis of Model A shows that, for every fixed fitness x, the network's degree distribution decays exponentially. In Model B we recover instead a power-law degree distribution whose exponent depends only on p, and we show how this result can be generalized. The properties of a number of particular networks are examined.
Mechanical design of the CDF SVX II silicon vertex detector
Skarha, J.E.
1994-08-01
A next generation silicon vertex detector is planned at CDF for the 1998 Tevatron collider run with the Main Injector. The SVX II silicon vertex detector will allow high luminosity data-taking, enable online triggering of secondary vertex production, and greatly increase the acceptance for heavy flavor physics at CDF. The design specifications, geometric layout, and early mechanical prototyping work for this detector are discussed.
The Mark II Vertex Drift Chamber
Alexander, J.P.; Baggs, R.; Fujino, D.; Hayes, K.; Hoard, C.; Hower, N.; Hutchinson, D.; Jaros, J.A.; Koetke, D.; Kowalski, L.A.
1989-03-01
We have completed constructing and begun operating the Mark II Drift Chamber Vertex Detector. The chamber, based on a modified jet cell design, achieves 30 {mu}m spatial resolution and <1000 {mu}m track-pair resolution in pressurized CO{sub 2} gas mixtures. Special emphasis has been placed on controlling systematic errors including the use of novel construction techniques which permit accurate wire placement. Chamber performance has been studied with cosmic ray tracks collected with the chamber located both inside and outside the Mark II. Results on spatial resolution, average pulse shape, and some properties of CO{sub 2} mixtures are presented. 10 refs., 12 figs., 1 tab.
Construction of the CDF silicon vertex detector
Skarha, J.; Barnett, B.; Boswell, C.; Snider, F.; Spies, A.; Tseng, J.; Vejcik, S. ); Carter, H.; Flaugher, B.; Gonzales, B.; Hrycyk, M.; Nelson, C.; Segler, S.; Shaw, T.; Tkaczyk, S.; Turner, K.; Wesson, T. ); Carithers, W.; Ely, R.; Haber, C.; Holland, S.; Kleinfelder, S.; Merrick, T.; Schneider, O.; Wester
1992-04-01
Technical details and methods used in constructing the CDF silicon vertex detector are presented. This description includes a discussion of the foam-carbon fiber composite structure used to silicon microstrip detectors and the procedure for achievement of 5 {mu}m detector alignment. The construction of the beryllium barrel structure, which houses the detector assemblies, is also described. In addition, the 10 {mu}m placement accuracy of the detectors in the barrel structure is discussed and the detector cooling and mounting systems are described. 12 refs.
Loop-quantum-gravity vertex amplitude.
Engle, Jonathan; Pereira, Roberto; Rovelli, Carlo
2007-10-19
Spin foam models are hoped to provide the dynamics of loop-quantum gravity. However, the most popular of these, the Barrett-Crane model, does not have the good boundary state space and there are indications that it fails to yield good low-energy n-point functions. We present an alternative dynamics that can be derived as a quantization of a Regge discretization of Euclidean general relativity, where second class constraints are imposed weakly. Its state space matches the SO(3) loop gravity one and it yields an SO(4)-covariant vertex amplitude for Euclidean loop gravity.
Drift chamber vertex detectors for SLC/LEP
Hayes, K.G.
1987-03-01
The short but measurable lifetimes of the b and c quarks and the tau lepton have motivated the development of high precision tracking detectors capable of providing information on the decay vertex topology of events containing these particles. This paper reviews the OPAL, L3, and MARK II experiments vertex drift chambers.
The Neuro-Z-Vertex Trigger of the Belle II Experiment
NASA Astrophysics Data System (ADS)
Skambraks, Sebastian; Neuhaus, Sara; Kiesling, Christian
2016-11-01
A neural network z vertex trigger is planned for the upcoming Belle II detector at the SuperKEKB collider. This neural algorithm is based on a single track 3D parameter estimation using only hit and drift time information from the central drift chamber. Due to the high luminosity (L = 8 × 1035 cm-2 s-1) Belle II will have to face high levels of beam induced background, making a z vertex reconstruction at the first level trigger mandatory. Using the neural z vertex algorithm, the requirements of the standard track trigger can be strongly relaxed. By this, the trigger efficiencies, especially for low multiplicity events, e.g. τ pair production, can be significantly increased. This contribution presents the foreseen neural network trigger setup and the preceding 2D track finder. Special focus is put on the proposal and evaluation of a possible 3D upgrade of the 2D track finder. Additionally, details are given on a dedicated setup for the upcoming cosmic ray test.
Twisted vertex algebras, bicharacter construction and boson-fermion correspondences
NASA Astrophysics Data System (ADS)
Anguelova, Iana I.
2013-12-01
The boson-fermion correspondences are an important phenomena on the intersection of several areas in mathematical physics: representation theory, vertex algebras and conformal field theory, integrable systems, number theory, cohomology. Two such correspondences are well known: the types A and B (and their super extensions). As a main result of this paper we present a new boson-fermion correspondence of type D-A. Further, we define a new concept of twisted vertex algebra of order N, which generalizes super vertex algebra. We develop the bicharacter construction which we use for constructing classes of examples of twisted vertex algebras, as well as for deriving formulas for the operator product expansions, analytic continuations, and normal ordered products. By using the underlying Hopf algebra structure we prove general bicharacter formulas for the vacuum expectation values for two important groups of examples. We show that the correspondences of types B, C, and D-A are isomorphisms of twisted vertex algebras.
Artificial Spin-Ice and Vertex Models
NASA Astrophysics Data System (ADS)
Cugliandolo, Leticia F.
2017-01-01
In classical and quantum frustrated magnets the interactions in combination with the lattice structure impede the spins to order in optimal configurations at zero temperature. The theoretical interest in their classical realisations has been boosted by the artificial manufacture of materials with these properties, that are of flexible design. This note summarises work on the use of vertex models to study bidimensional spin-ices samples, done in collaboration with R. A. Borzi, M. V. Ferreyra, L. Foini, G. Gonnella, S. A. Grigera, P. Guruciaga, D. Levis, A. Pelizzola and M. Tarzia, in recent years. It is an invited contribution to a J. Stat. Mech. special issue dedicated to the memory of Leo P. Kadanoff.
Evaluation of new spin foam vertex amplitudes
NASA Astrophysics Data System (ADS)
Khavkine, Igor
2009-06-01
The Christensen-Egan algorithm is extended and generalized to efficiently evaluate new spin foam vertex amplitudes proposed by Engle, Pereira and Rovelli and Freidel and Krasnov, with or without (factored) boundary states. A concrete pragmatic proposal is made for comparing the different models using uniform methodologies, applicable to the behavior of large spin asymptotics and of expectation values of specific semiclassical observables. The asymptotics of the new models exhibit non-oscillatory, power-law decay similar to that of the Barrett-Crane model, though with different exponents. Also, an analysis of the semiclassical wave packet propagation problem indicates that the Magliaro, Rovelli and Perini's conjecture of good semiclassical behavior of the new models does not hold for generic factored states, which neglect spin-spin correlations.
The upgrade of the LHCb Vertex Locator
NASA Astrophysics Data System (ADS)
Bird, T.
2014-12-01
The LHCb experiment is set for a significant upgrade, which will be ready for Run 3 of the LHC in 2020. This upgrade will allow LHCb to run at a significantly higher instantaneous luminosity and collect an integrated luminosity of 50fb-1 by the end of Run 4. In this process the Vertex Locator (VELO) detector will be upgraded to a pixel-based silicon detector. The upgraded VELO will improve upon the current detector by being closer to the beams and having lower material modules with microchannel cooling and a thinner RF-foil. Simulations have shown that it will maintain its excellent performance, even after the radiation damage caused by collecting an integrated luminosity of 50fb-1.
Compton scattering vertex for massive scalar QED
Bashir, A.; Concha-Sanchez, Y.; Delbourgo, R.; Tejeda-Yeomans, M. E.
2009-08-15
We investigate the Compton scattering vertex of charged scalars and photons in scalar quantum electrodynamics (SQED). We carry out its nonperturbative construction consistent with Ward-Fradkin-Green-Takahashi identity which relates 3-point vertices to the 4-point ones. There is an undetermined part which is transverse to one or both the external photons, and needs to be evaluated through perturbation theory. We present in detail how the transverse part at the 1-loop order can be evaluated for completely general kinematics of momenta involved in covariant gauges and dimensions. This involves the calculation of genuine 4-point functions with three massive propagators, the most nontrivial integrals reported in this paper. We also discuss possible applications of our results.
Measurement of the B^{±} lifetime and top quark identification using secondary vertex b-tagging
Schwartzman, Ariel G.
2004-01-01
This dissertation presents a preliminary measurement of the B^{±} lifetime through the full reconstruction of its decay chain, and the identification of top quark production in the electron plus jets channel using the displaced vertex b-tagging method. Its main contribution is the development, implementation and optimization of the Kalman filter algorithm for vertex reconstruction, and of the displaced vertex technique for tagging jets arising from b quark fragmentation, both of which have now become part of the standard D0 reconstruction package. These two algorithms fully exploit the new state-of-the-art tracking detectors, recently installed as part of the Run 2 D0 upgrade project. The analysis is based on data collected during Run 2a at the Fermilab Tevatron p$\\bar{p}$ Hadron Collider up to April 2003, corresponding to an integrated luminosity of 60 pb^{-1}. The measured B meson lifetime of τ = 1.57 ± 0.18 ps is in agreement with the current world average, with a competitive level of precision expected when the full data sample becomes available.
Locking mechanisms in degree-4 vertex origami structures
NASA Astrophysics Data System (ADS)
Fang, Hongbin; Li, Suyi; Xu, Jian; Wang, K. W.
2016-04-01
Origami has emerged as a potential tool for the design of mechanical metamaterials and metastructures whose novel properties originate from their crease patterns. Most of the attention in origami engineering has focused on the wellknown Miura-Ori, a folded tessellation that is flat-foldable for folded sheet and stacked blocks. This study advances the state of the art and expands the research field to investigate generic degree-4 vertex (4-vertex) origami, with a focus on facet-binding. In order to understand how facet-binding attributes to the mechanical properties of 4-vertex origami structures, geometries of the 4-vertex origami cells are analyzed and analytically expressed. Through repeating and stacking 4-vertex cells, origami sheets and stacked origami blocks can be constructed. Geometry analyses discover four mechanisms that will lead to the self-locking of 4-vertex origami cells, sheets, and stacked blocks: in-cell facet-binding, inlayer facet-binding, inter-layer facet binding, and in-layer and inter-layer facet-bindings. These mechanisms and the predicted self-locking phenomena are verified through 3D simulations and prototype experiments. Finally, this paper briefly introduces the unusual mechanical properties caused by the locking of 4-vertex origami structures. The research reported in this paper could foster a new breed of self-locking structures with various engineering applications.
Quark-gluon vertex model and lattice-QCD data
Bhagwat, M.S.; Tandy, P.C.
2004-11-01
A model for the dressed-quark-gluon vertex, at zero gluon momentum, is formed from a nonperturbative extension of the two Feynman diagrams that contribute at one loop in perturbation theory. The required input is an existing ladder-rainbow model Bethe-Salpeter kernel from an approach based on the Dyson-Schwinger equations; no new parameters are introduced. The model includes an Ansatz for the triple-gluon vertex. Two of the three vertex amplitudes from the model provide a pointwise description of the recent quenched-lattice-QCD data. An estimate of the effects of quenching is made.
Superstring vertex operators in type IIB matrix model
Kitazawa, Yoshihisa; Nagaoka, Satoshi
2008-06-15
We clarify the relation between the vertex operators in type IIB matrix model and superstring. Green-Schwarz light-cone closed superstring theory is obtained from IIB matrix model on two-dimensional noncommutative backgrounds. Superstring vertex operators should be reproduced from those of IIB matrix model through this connection. Indeed, we confirm that supergravity vertex operators in IIB matrix model on the two-dimensional backgrounds reduce to those in superstring theory. Noncommutativity plays an important role in our identification. Through this correspondence, we can reproduce superstring scattering amplitudes from IIB matrix model.
Quark-gluon vertex in arbitrary gauge and dimension
NASA Astrophysics Data System (ADS)
Davydychev, A. I.; Osland, P.; Saks, L.
2001-01-01
One-loop off-shell contributions to the quark-gluon vertex are calculated, in an arbitrary covariant gauge and in arbitrary space-time dimension, including quark-mass effects. It is shown how one can get results for all on-shell limits of interest directly from the off-shell expressions. In order to demonstrate that the Ward-Slavnov-Taylor identity for the quark-gluon vertex is satisfied, we have also calculated the corresponding one-loop contribution involving the quark-quark-ghost-ghost vertex.
The formation of a yield-surface vertex in rock
Olsson, W.A.
1992-01-01
Microstructural models of deformation of polycrystalline materials suggest that inelastic deformation leads to the formation of a corner or vertex at the current load point. This vertex can cause the response to non-proportional loading to be more compliant than predicted by the smooth yield-surface idealization. Combined compression-torsion experiments on Tennessee marble indicate that a vertex forms during inelastic flow. An important implication is that strain localization by bifurcation occurs earlier than predicted by bifurcation analysis using isotropic hardening.
A two-level fanout system for the CDF silicon vertex tracker
A. Bardi et al.
2001-11-02
The Fanout system is part of the Silicon Vertex Tracker, a new trigger processor designed to reconstruct charged particle trajectories at Level 2 of the CDF trigger, with a latency of 10 {micro}s and an event rate up to 100 kHz. The core of SVT is organized as 12 identical slices, which process in parallel the data from the 12 independent azimuthal wedges of the Silicon Vertex Detector (SVXII). Each SVT slice links the digitized pulse heights found within one SVXII wedge to the tracks reconstructed by the Level 1 fast track finder (XFT) in the corresponding 30{sup o} angular region of the Central Outer Tracker. Since the XFT tracks are transmitted to SVT as a single data stream, their distribution to the proper SVT slices requires dedicated fanout logic. The Fanout system has been implemented as a multi-board project running on a common 20 MHz clock. Track fanout is performed in two steps by one ''Fanout A'' and two ''Fanout B'' boards. The architecture, design, and implementation of this system are described.
Vertex micromagnetic energy in artificial square ice
NASA Astrophysics Data System (ADS)
Perrin, Yann; Canals, Benjamin; Rougemaille, Nicolas
2016-10-01
Artificial arrays of interacting magnetic elements provide an uncharted arena in which the physics of magnetic frustration and magnetic monopoles can be observed in real space and in real time. These systems offer the formidable opportunity to investigate a wide range of collective magnetic phenomena with a lab-on-chip approach and to explore various theoretical predictions from spin models. Here, we study artificial square ice systems numerically and use micromagnetic simulations to understand how the geometrical parameters of the individual magnetic elements affect the energy levels of an isolated square vertex. More specifically, we address the question of whether the celebrated square ice model could be made relevant for artificial square ice systems. Our work reveals that tuning the geometry alone should not allow the experimental realization of the square ice model when using nanomagnets coupled through the magnetostatic interaction. However, low-aspect ratios combined with small gaps separating neighboring magnetic elements of moderated thickness might permit approaching the ideal case where the degeneracy of the ice rule states is recovered.
The Belle II Silicon Vertex Detector
NASA Astrophysics Data System (ADS)
Friedl, M.; Bergauer, T.; Dolejschi, P.; Frankenberger, A.; Gfall, I.; Irmler, C.; Obermayer, T.; Onuki, Y.; Smiljic, D.; Tsuboyama, T.; Valentan, M.
The KEKB factory (Tsukuba, Japan) has been shut down in mid-2010 after reaching a total integrated luminosity of 1ab-1. Recently, the work on an upgrade of the collider (SuperKEKB), aiming at an ultimate luminosity of 8×1035 cm-2s-1, has started. This is 40 times the peak value of the previous system and thus also requires a redesign of the Belle detector (leading to Belle II), especially its Silicon Vertex Detector (SVD), which surrounds the beam pipe. Similar to its predecessor, the future Belle II SVD will again consist of four layers of double-sided silicon strip sensors (DSSD), but at higher radii. Moreover, a double-layer PiXel Detector (PXD) will complement the SVD as the innermost sensing device. All DSSDs will be made from 6" silicon wafers and read out by APV25 chips, which were originally developed for the CMS experiment. That system was proven to meet the requirements for Belle II in matters of occupancy and dead time. Since the KEKB factory operates at relatively low energy, material inside the active volume has to be minimized in order to reduce multiple scattering. This can be achieved by the Origami chip-on-sensor concept, including a very light-weight mechanical support structure made from carbon fiber reinforced Airex foam. Moreover, CO2 cooling for the front-end chips will ensure high efficiency at minimum material budget.
Linear Time Vertex Partitioning on Massive Graphs.
Mell, Peter; Harang, Richard; Gueye, Assane
The problem of optimally removing a set of vertices from a graph to minimize the size of the largest resultant component is known to be NP-complete. Prior work has provided near optimal heuristics with a high time complexity that function on up to hundreds of nodes and less optimal but faster techniques that function on up to thousands of nodes. In this work, we analyze how to perform vertex partitioning on massive graphs of tens of millions of nodes. We use a previously known and very simple heuristic technique: iteratively removing the node of largest degree and all of its edges. This approach has an apparent quadratic complexity since, upon removal of a node and adjoining set of edges, the node degree calculations must be updated prior to choosing the next node. However, we describe a linear time complexity solution using an array whose indices map to node degree and whose values are hash tables indicating the presence or absence of a node at that degree value. This approach also has a linear growth with respect to memory usage which is surprising since we lowered the time complexity from quadratic to linear. We empirically demonstrate linear scalability and linear memory usage on random graphs of up to 15000 nodes. We then demonstrate tractability on massive graphs through execution on a graph with 34 million nodes representing Internet wide router connectivity.
Linear Time Vertex Partitioning on Massive Graphs
Mell, Peter; Harang, Richard; Gueye, Assane
2016-01-01
The problem of optimally removing a set of vertices from a graph to minimize the size of the largest resultant component is known to be NP-complete. Prior work has provided near optimal heuristics with a high time complexity that function on up to hundreds of nodes and less optimal but faster techniques that function on up to thousands of nodes. In this work, we analyze how to perform vertex partitioning on massive graphs of tens of millions of nodes. We use a previously known and very simple heuristic technique: iteratively removing the node of largest degree and all of its edges. This approach has an apparent quadratic complexity since, upon removal of a node and adjoining set of edges, the node degree calculations must be updated prior to choosing the next node. However, we describe a linear time complexity solution using an array whose indices map to node degree and whose values are hash tables indicating the presence or absence of a node at that degree value. This approach also has a linear growth with respect to memory usage which is surprising since we lowered the time complexity from quadratic to linear. We empirically demonstrate linear scalability and linear memory usage on random graphs of up to 15000 nodes. We then demonstrate tractability on massive graphs through execution on a graph with 34 million nodes representing Internet wide router connectivity. PMID:27336059
Vertex models: from cell mechanics to tissue morphogenesis.
Alt, Silvanus; Ganguly, Poulami; Salbreux, Guillaume
2017-05-19
Tissue morphogenesis requires the collective, coordinated motion and deformation of a large number of cells. Vertex model simulations for tissue mechanics have been developed to bridge the scales between force generation at the cellular level and tissue deformation and flows. We review here various formulations of vertex models that have been proposed for describing tissues in two and three dimensions. We discuss a generic formulation using a virtual work differential, and we review applications of vertex models to biological morphogenetic processes. We also highlight recent efforts to obtain continuum theories of tissue mechanics, which are effective, coarse-grained descriptions of vertex models.This article is part of the themed issue 'Systems morphodynamics: understanding the development of tissue hardware'.
Vertex models: from cell mechanics to tissue morphogenesis
Alt, Silvanus; Ganguly, Poulami
2017-01-01
Tissue morphogenesis requires the collective, coordinated motion and deformation of a large number of cells. Vertex model simulations for tissue mechanics have been developed to bridge the scales between force generation at the cellular level and tissue deformation and flows. We review here various formulations of vertex models that have been proposed for describing tissues in two and three dimensions. We discuss a generic formulation using a virtual work differential, and we review applications of vertex models to biological morphogenetic processes. We also highlight recent efforts to obtain continuum theories of tissue mechanics, which are effective, coarse-grained descriptions of vertex models. This article is part of the themed issue ‘Systems morphodynamics: understanding the development of tissue hardware’. PMID:28348254
Efficient variants of the vertex space domain decomposition algorithm
Chan, T.F.; Shao, J.P. . Dept. of Mathematics); Mathew, T.P. . Dept. of Mathematics)
1994-11-01
Several variants of the vertex space algorithm of Smith for two-dimensional elliptic problems are described. The vertex space algorithm is a domain decomposition method based on nonoverlapping subregions, in which the reduced Schur complement system on the interface is solved using a generalized block Jacobi-type preconditioner, with the blocks corresponding to the vertex space, edges, and a coarse grid. Two kinds of approximations are considered for the edge and vertex space subblocks, one based on Fourier approximation, and another based on an algebraic probing technique in which sparse approximations to these subblocks are computed. The motivation is to improve the efficiency of the algorithm without sacrificing the optimal convergence rate. Numerical and theoretical results on the performance of these algorithms, including variants of an algorithm of Bramble, Pasciak, and Schatz are presented.
The vertex detector for the Lepton/Photon collaboration
Sullivan, J.P.; Boissevain, J.G.; Fox, D.; Hecke, H. van; Jacak, B.V.; Kapustinsky, J.S.; Leitch, M.J.; McGaughey, P.L.; Moss, J.M.; Sondheim, W.E.
1991-12-31
The conceptual design of the vertex detector for the Lepton/Photon Collaboration at RHIC is described, including simulations of its expected performance. The design consists of two con- centric layers of single-sided Si strips. The expected performance as a multiplicity detector and in measuring the pseudo-rapidity ({nu}) distribution is discussed as well as the expected vertex finding efficiency and accuracy. Various options which could be used to reduce the cost of the detector are also discussed.
Hessian and graviton propagator of the proper vertex
NASA Astrophysics Data System (ADS)
Chaharsough Shirazi, Atousa; Engle, Jonathan; Vilensky, Ilya
2016-10-01
The proper spin-foam vertex amplitude is obtained from the EPRL vertex by projecting out all but a single gravitational sector, in order to achieve correct semi-classical behavior. In this paper we calculate the gravitational two-point function predicted by the proper spin-foam vertex to lowest order in the vertex expansion. We find the same answer as in the EPRL case in the ‘continuum spectrum’ limit, so that the theory is consistent with the predictions of linearized gravity in the regime of small curvature. The method for calculating the two-point function is similar to that used in prior works: we cast it in terms of an action integral and use stationary phase methods. Thus, the calculation of the Hessian matrix plays a key role. Once the Hessian is calculated, it is used not only to calculate the two-point function, but also to calculate the coefficient appearing in the semi-classical limit of the proper vertex amplitude itself. This coefficient is the effective discrete ‘measure factor’ encoded in the spin-foam model. Through a non-trivial cancellation of different factors, we find that this coefficient is the same as the coefficient in front of the term in the asymptotics of the EPRL vertex corresponding to the selected gravitational sector.
ERIC Educational Resources Information Center
Childers, Annie Burns; Vidakovic, Draga
2014-01-01
This paper explores sixty-six students' personal meaning and interpretation of the vertex of a quadratic function in relation to their understanding of quadratic functions in two different representations, algebraic and word problem. Several categories emerged from students' personal meaning of the vertex including vertex as maximum or minimum…
VERTEX: manganese transport through oxygen minima
NASA Astrophysics Data System (ADS)
Martin, John H.; Knauer, George A.
1984-01-01
Manganese transport through a well-developed oxygen minimum was studied off central Mexico (18°N, 108°W) in October-November 1981 as part of the VERTEX (Vertical Transport and Exchange) research program. Refractory, leachable and dissolved Mn fractions associated with particulates caught in traps set at eight depths (120-1950 m) were analyzed. Particles entering the oxygen minimum had relatively large Mn loads; however, as the particulates sank further into the minimum, total Mn fluxes steadily decreased from 190 nmol m -2 day -1 at 120 m to 36 nmol m -2 day -1 at 400 m. Manganese fluxes then steadily increased in the remaining 800-1950 m, reaching rates of up to 230 nmol m -2 day -1 at 1950 m. Manganese concentrations were also measured in the water column. Dissolved Mn levels < 3.0 nmol kg -1 were consistently observed within the 150-600 m depth interval. In contrast, suspended particulate leachable Mn amounts were especially low at those depths, and never exceeded 0.04 nmol kg -1. The combined water column and particle trap data clearly indicate that Mn is released from particles as they sink through the oxygen minimum. Rate-of-change estimates based on trap flux data yield regeneration rates of up to 0.44 nmol kg -1 yr -1 in the upper oxygen minimum (120-200 m). However, only 30% of the dissolved Mn in the oxygen minimum appears to be from sinking particulate regeneration; the other 70% probably results from continental-slope-release-horizontal-transport processes. Dissolved Mn scavenges back onto particles as oxygen levels begin to increase with depth. Scavenging rates ranging from -0.03 to -0.09 nmol kg -1 yr -1 were observed at depths from 700 to 1950 m. These scavenging rates result in Mn residence times of 16-19 years, and scavenging rate constants on the order of 0.057 yr -1. Manganese removal via scavenging on sinking particles below the oxygen minimum is balanced by Mn released along continental boundaries and transported horizontally via advective
An upwind vertex centred Finite Volume solver for Lagrangian solid dynamics
NASA Astrophysics Data System (ADS)
Aguirre, Miquel; Gil, Antonio J.; Bonet, Javier; Lee, Chun Hean
2015-11-01
A vertex centred Jameson-Schmidt-Turkel (JST) finite volume algorithm was recently introduced by the authors (Aguirre et al., 2014 [1]) in the context of fast solid isothermal dynamics. The spatial discretisation scheme was constructed upon a Lagrangian two-field mixed (linear momentum and the deformation gradient) formulation presented as a system of conservation laws [2-4]. In this paper, the formulation is further enhanced by introducing a novel upwind vertex centred finite volume algorithm with three key novelties. First, a conservation law for the volume map is incorporated into the existing two-field system to extend the range of applications towards the incompressibility limit (Gil et al., 2014 [5]). Second, the use of a linearised Riemann solver and reconstruction limiters is derived for the stabilisation of the scheme together with an efficient edge-based implementation. Third, the treatment of thermo-mechanical processes through a Mie-Grüneisen equation of state is incorporated in the proposed formulation. For completeness, the study of the eigenvalue structure of the resulting system of conservation laws is carried out to demonstrate hyperbolicity and obtain the correct time step bounds for non-isothermal processes. A series of numerical examples are presented in order to assess the robustness of the proposed methodology. The overall scheme shows excellent behaviour in shock and bending dominated nearly incompressible scenarios without spurious pressure oscillations, yielding second order of convergence for both velocities and stresses.
Three-dimensional vertex model for simulating multicellular morphogenesis
Okuda, Satoru; Inoue, Yasuhiro; Adachi, Taiji
2015-01-01
During morphogenesis, various cellular activities are spatiotemporally coordinated on the protein regulatory background to construct the complicated, three-dimensional (3D) structures of organs. Computational simulations using 3D vertex models have been the focus of efforts to approach the mechanisms underlying 3D multicellular constructions, such as dynamics of the 3D monolayer or multilayer cell sheet like epithelia as well as the 3D compacted cell aggregate, including dynamic changes in layer structures. 3D vertex models enable the quantitative simulation of multicellular morphogenesis on the basis of single-cell mechanics, with complete control of various cellular activities such as cell contraction, growth, rearrangement, division, and death. This review describes the general use of the 3D vertex model, along with its applications to several simplified problems of developmental phenomena. PMID:27493850
Plethystic vertex operators and boson-fermion correspondences
NASA Astrophysics Data System (ADS)
Fauser, Bertfried; Jarvis, Peter D.; King, Ronald C.
2016-10-01
We study the algebraic properties of plethystic vertex operators, introduced in (2010 J. Phys. A: Math. Theor. 43 405202), underlying the structure of symmetric functions associated with certain generalized universal character rings of subgroups of the general linear group, defined to stabilize tensors of Young symmetry type characterized by a partition of arbitrary shape π. Here we establish an extension of the well-known boson-fermion correspondence involving Schur functions and their associated (Bernstein) vertex operators: for each π, the modes generated by the plethystic vertex operators and their suitably constructed duals, satisfy the anticommutation relations of a complex Clifford algebra. The combinatorial manipulations underlying the results involve exchange identities exploiting the Hopf-algebraic structure of certain symmetric function series and their plethysms.
Simulations of silicon vertex tracker for star experiment at RHIC
Odyniec, G.; Cebra, D.; Christie, W.; Naudet, C.; Schroeder, L.; Wilson, W.; Liko, D.; Cramer, J.; Prindle, D.; Trainor, T.; Braithwaite, W.
1991-12-31
The first computer simulations to optimize the Silicon Vertex Tracker (SVT) designed for the STAR experiment at RHIC are presented. The physics goals and the expected complexity of the events at RHIC dictate the design of a tracking system for the STAR experiment. The proposed tracking system will consist of a silicon vertex tracker (SVT) to locate the primary interaction and secondary decay vertices and to improve the momentum resolution, and a time projection chamber (TPC), positioned inside a solenoidal magnet, for continuous tracking.
A GPU algorithm for minimum vertex cover problems
NASA Astrophysics Data System (ADS)
Toume, Kouta; Kinjo, Daiki; Nakamura, Morikazu
2014-10-01
The minimum vertex cover problem is one of the fundamental problems in graph theory and is known to be NP-hard. For data mining in large-scale structured systems, we proposes a GPU algorithm for the minimum vertex cover problem. The algorithm is designed to derive sufficient parallelism of the problem for the GPU architecture and also to arrange data on the device memory for efficient coalesced accessing. Through the experimental evaluation, we demonstrate that our GPU algorithm is quite faster than CPU programs and the speedup becomes much evident when the graph size is enlarged.
The prototype of the Micro Vertex Detector of the CBM Experiment
NASA Astrophysics Data System (ADS)
Koziel, Michal; Amar-Youcef, Samir; Bialas, Norbert; Deveaux, Michael; Fröhlich, Ingo; Li, Qiyan; Michel, Jan; Milanović, Borislav; Müntz, Christian; Neumann, Bertram; Schrader, Christoph; Stroth, Joachim; Tischler, Tobias; Weirich, Roland; Wiebusch, Michael
2013-12-01
The Compressed Baryonic Matter (CBM) Experiment is one of the core experiments of the future FAIR facility at Darmstadt, Germany. This fixed-target experiment will explore the phase diagram of strongly interacting matter in the regime of highest net baryon densities with numerous probes, among them open charm. Reconstructing those short lived particles requires a vacuum compatible Micro Vertex Detector (MVD) with unprecedented properties. Its sensor technology has to feature a spatial resolution of <5 μm, a non-ionizing radiation tolerance of >1013 neq/cm2, an ionizing radiation tolerance of >3 Mrad and a time resolution of a few 10 μs. The MVD-prototype project aimed to study the integration the CMOS Monolithic Active Pixel Sensors foreseen for the MVD into an ultra light (0.3% X0) and a vacuum compatible detector system based on a cooling support made of CVD-diamond.
The ``Roman pot'' spectrometer and the vertex detector of experiment UA4 at the CERN SPS collider
NASA Astrophysics Data System (ADS)
Battiston, R.; Bechini, A.; Bosi, F.; Bozzo, M.; Braccini, P. L.; Buskens, J.; Carbonara, F.; Carrara, R.; Castaldi, R.; Cazzola, U.; Cervelli, F.; Chiefari, G.; Drago, E.; Gorini, R.; Haguenauer, M.; Koene, B.; Maleyran, R.; Manna, F.; Matthiae, G.; Merola, L.; Morelli, A.; Napolitano, M.; Palladino, V.; Rewiersma, P.; Robert, M.; Roiron, G.; Sanguinetti, G.; Schuijlenburg, H.; Sciacca, G.; Sette, G.; Van Swol, R.; Timmermans, J.; Traspedini, L.; Vannini, C.; Velasco, J.; Visco, F.
1985-07-01
We describe the apparatus used in experiment UA4 to study proton-antiproton elastic and inelastic interactions at the CERN SPS Collider. Elastically scattered particles, travelling at very small angles, are observed by detectors placed inside movable sections ("Roman pots") of the SPS vacuum chamber. The deflection in the field of the machine quadrupoles allow the measurement of the particle momentum. Inelastic interactions are observed by a left-right symmetric system of trigger counter hodoscopes and drift-chamber telescopes. The apparatus reconstructs the interaction vertex and measures the pseudorapidity η of charged particles in the range 2.5 < ‖ η‖ < 5.6.
A Cohomology Theory of Grading-Restricted Vertex Algebras
NASA Astrophysics Data System (ADS)
Huang, Yi-Zhi
2014-04-01
We introduce a cohomology theory of grading-restricted vertex algebras. To construct the correct cohomologies, we consider linear maps from tensor powers of a grading-restricted vertex algebra to "rational functions valued in the algebraic completion of a module for the algebra," instead of linear maps from tensor powers of the algebra to a module for the algebra. One subtle complication arising from such functions is that we have to carefully address the issue of convergence when we compose these linear maps with vertex operators. In particular, for each , we have an inverse system of nth cohomologies and an additional nth cohomology of a grading-restricted vertex algebra V with coefficients in a V-module W such that is isomorphic to the inverse limit of the inverse system . In the case of n = 2, there is an additional second cohomology denoted by which will be shown in a sequel to the present paper to correspond to what we call square-zero extensions of V and to first order deformations of V when W = V.
Recent developments in high precision vertex chambers at SLAC
Rust, D.R.
1984-04-01
Three detectors MARK II, MAC, AND HRS are using or planning small drift chambers placed as close as possible to the interaction print at PEP. There is also a program of development for a gaseous vertex detector for MARK II at SLC. All these programs are reviewed. 13 references.
Tests of track segment and vertex finding with neural networks
Denby, B.; Lessner, E. ); Lindsey, C.S. )
1990-04-01
Feed forward neural networks have been trained, using back-propagation, to find the slopes of simulated track segments in a straw chamber and to find the vertex of tracks from both simulated and real events in a more conventional drift chamber geometry. Network architectures, training, and performance are presented. 12 refs., 7 figs.
SVX{prime}, the new CDF silicon vertex detector
Cihangir, S.; Gillespie, G.; Gonzalez, H.
1994-08-26
The Collider Detector at Fermilab (CDF) radiation hardened silicon vertex detector (SVX{prime}) is described. The new detector has several improvements over its predecessor such as better signal to noise and higher efficiency. It`s expected to have a radiation tolerance in excess of 1 Mrad. It has been taking data for several months and some preliminary results are shown.
Self-locking degree-4 vertex origami structures
NASA Astrophysics Data System (ADS)
Fang, Hongbin; Li, Suyi; Wang, K. W.
2016-11-01
A generic degree-4 vertex (4-vertex) origami possesses one continuous degree-of-freedom for rigid folding, and this folding process can be stopped when two of its facets bind together. Such facet-binding will induce self-locking so that the overall structure stays at a pre-specified configuration without additional locking elements or actuators. Self-locking offers many promising properties, such as programmable deformation ranges and piecewise stiffness jumps, that could significantly advance many adaptive structural systems. However, despite its excellent potential, the origami self-locking features have not been well studied, understood, and used. To advance the state of the art, this research conducts a comprehensive investigation on the principles of achieving and harnessing self-locking in 4-vertex origami structures. Especially, for the first time, this study expands the 4-vertex structure construction from single-component to dual-component designs and investigates their self-locking behaviours. By exploiting various tessellation designs, this research discovers that the dual-component designs offer the origami structures with extraordinary attributes that the single-component structures do not have, which include the existence of flat-folded locking planes, programmable locking points and deformability. Finally, proof-of-concept experiments investigate how self-locking can effectively induce piecewise stiffness jumps. The results of this research provide new scientific knowledge and a systematic framework for the design, analysis and utilization of self-locking origami structures for many potential engineering applications.
The role of geometry in 4-vertex origami mechanics
NASA Astrophysics Data System (ADS)
Waitukaitis, Scott; Dieleman, Peter; van Hecke, Martin
Origami offers an interesting design platform metamaterials because it strongly couples mechanics with geometry. Even so, most research carried out so far has been limited to one or two particular patterns. I will discuss the full geometrical space of the most common origami building block, the 4-vertex, and show how exotic geometries can have dramatic effects on the mechanics.
Self-locking degree-4 vertex origami structures.
Fang, Hongbin; Li, Suyi; Wang, K W
2016-11-01
A generic degree-4 vertex (4-vertex) origami possesses one continuous degree-of-freedom for rigid folding, and this folding process can be stopped when two of its facets bind together. Such facet-binding will induce self-locking so that the overall structure stays at a pre-specified configuration without additional locking elements or actuators. Self-locking offers many promising properties, such as programmable deformation ranges and piecewise stiffness jumps, that could significantly advance many adaptive structural systems. However, despite its excellent potential, the origami self-locking features have not been well studied, understood, and used. To advance the state of the art, this research conducts a comprehensive investigation on the principles of achieving and harnessing self-locking in 4-vertex origami structures. Especially, for the first time, this study expands the 4-vertex structure construction from single-component to dual-component designs and investigates their self-locking behaviours. By exploiting various tessellation designs, this research discovers that the dual-component designs offer the origami structures with extraordinary attributes that the single-component structures do not have, which include the existence of flat-folded locking planes, programmable locking points and deformability. Finally, proof-of-concept experiments investigate how self-locking can effectively induce piecewise stiffness jumps. The results of this research provide new scientific knowledge and a systematic framework for the design, analysis and utilization of self-locking origami structures for many potential engineering applications.
Status and upgrade plans of the Belle silicon vertex detector
NASA Astrophysics Data System (ADS)
Aihara, H.; Arakawa, T.; Asano, Y.; Aso, T.; Bakich, A.; Barbero, M.; Browder, T.; Chang, M. C.; Chao, Y.; Chen, K. F.; Chidzik, S.; Chouvikov, A.; Choi, Y. K.; Das, A.; Dalseno, J.; Fratina, S.; Friedl, M.; Fujiyama, Y.; Haba, J.; Hara, K.; Hara, T.; Harrop, B.; Hayashi, K.; Hazumi, M.; Heffernan, D.; Higuchi, T.; Hirakawa, T.; Irmler, C.; Ishino, H.; Joshi, N. K.; Kajiwara, S.; Kakuno, H.; Kameshima, T.; Kawasaki, T.; Kibayashi, A.; Kim, Y. J.; Koike, S.; Korpar, S.; Križan, P.; Kurashiro, H.; Kusaka, A.; Marlow, D.; Miyake, H.; Moloney, G. R.; Nakahama, Y.; Natkaniec, Z.; Okuno, S.; Ono, S.; Ostrowicz, W.; Ozaki, H.; Peak, L.; Pernicka, M.; Rosen, M.; Rozanska, M.; Sato, N.; Schmid, S.; Schümann, J.; Stanič, S.; Steininger, H.; Sumisawa, K.; Tajima, O.; Takahashi, T.; Tamura, N.; Tanaka, M.; Tani, N.; Taylor, G. N.; Trabelsi, K.; Tsuboyama, T.; Uchida, K.; Ueno, K.; Ushiroda, Y.; Varner, G.; Varvell, K.; Velikzhanin, Y. S.; Wang, C. C.; Wang, M. Z.; Watanabe, M.; Watanabe, Y.; Yamamoto, H.; Yamashita, Y.; Ziegler, T.
2007-12-01
The second generation of Belle Silicon Vertex Detector (SVD) has been efficiently operated for more than three years. With increasing beam-induced background, a degradation of the detector performance is expected. To avoid such a difficulty, we are planing a next upgrade, the third generation of the SVD. Currently, its design is almost finalized.
Proposed proper Engle-Pereira-Rovelli-Livine vertex amplitude
NASA Astrophysics Data System (ADS)
Engle, Jonathan
2013-04-01
As established in a prior work of the author, the linear simplicity constraints used in the construction of the so-called “new” spin-foam models mix three of the five sectors of Plebanski theory as well as two dynamical orientations, and this is the reason for multiple terms in the asymptotics of the Engle-Pereira-Rovelli-Livine vertex amplitude as calculated by Barrett et al. Specifically, the term equal to the usual exponential of i times the Regge action corresponds to configurations either in sector (II+) with positive orientation or sector (II-) with negative orientation. The presence of the other terms beyond this cause problems in the semiclassical limit of the spin-foam model when considering multiple 4-simplices due to the fact that the different terms for different 4-simplices mix in the semiclassical limit, leading in general to a non-Regge action and hence non-Regge and nongravitational configurations persisting in the semiclassical limit. To correct this problem, we propose to modify the vertex so its asymptotics include only the one term of the form eiSRegge. To do this, an explicit classical discrete condition is derived that isolates the desired gravitational sector corresponding to this one term. This condition is quantized and used to modify the vertex amplitude, yielding what we call the “proper Engle-Pereira-Rovelli-Livine vertex amplitude.” This vertex still depends only on standard SU(2) spin-network data on the boundary, is SU(2) gauge-invariant, and is linear in the boundary state, as required. In addition, the asymptotics now consist in the single desired term of the form eiSRegge, and all degenerate configurations are exponentially suppressed. A natural generalization to the Lorentzian signature is also presented.
Empty versus filled polyhedra: 11 vertex bare germanium clusters.
Uţă, Matei-Maria; King, Robert Bruce
2014-04-01
The structures and energetics of centered 10-vertex Ge@Ge₁₀(z) (z = -4, -2, 0, +2, +4) clusters have been investigated by density functional theory (DFT) for comparison with the previously studied isomeric empty 11-vertex Ge₁₁(z) clusters. For the cationic species (z = +2, +4) such centered Ge@Ge₁₀(z) structures are shown to be energetically competitive (within ∼1 kcal mol⁻¹) to the lowest energy isomeric empty Ge₁₁(z) structures. These Ge@Ge₁₀(z) structures can be derived from the lowest energy empty 10-vertex Ge₁₀(z-4) structures by inserting a Ge⁴⁺ ion in the center. The outer 10-vertex polyhedron in the lowest energy Ge@Ge₁₀²⁺ dication structure is the most spherical D(4d) bicapped square antiprism, which is also the lowest energy structure of the empty Ge₁₀²⁻ dianion, as expected from the Wade-Mingos skeletal electron counting rules. For the tetracationic Ge₁₁⁴⁺ /Ge@Ge₁₀⁴⁺ system the lowest energy centered Ge@Ge₁₀⁴⁺ structure can be obtained by inserting a Ge⁴⁺ ion in the center of a C(3v) deltahedral empty Ge10 cluster. Centered 10-vertex polyhedral Ge@Ge₁₀(z) structures were also found for the neutral (z = 0) and dianionic (z = -2) systems but at significantly higher energies than the lowest energy isomeric empty Ge₁₁(z) structures.
A quantum hybrid with a thin antenna at the vertex of a wedge
NASA Astrophysics Data System (ADS)
Carlone, Raffaele; Posilicano, Andrea
2017-03-01
We study the spectrum, resonances and scattering matrix of a quantum Hamiltonian on a "hybrid surface" consisting of a half-line attached by its endpoint to the vertex of a concave planar wedge. At the boundary of the wedge, outside the vertex, homogeneous Dirichlet conditions are imposed. The system is tunable by varying the measure of the angle at the vertex.
Vertex detectors: The state of the art and future prospects
Damerell, C.J.S.
1997-01-01
We review the current status of vertex detectors (tracking microscopes for the recognition of charm and bottom particle decays). The reasons why silicon has become the dominant detector medium are explained. Energy loss mechanisms are reviewed, as well as the physics and technology of semiconductor devices, emphasizing the areas of most relevance for detectors. The main design options (microstrips and pixel devices, both CCD`s and APS`s) are discussed, as well as the issue of radiation damage, which probably implies the need to change to detector media beyond silicon for some vertexing applications. Finally, the evolution of key performance parameters over the past 15 years is reviewed, and an attempt is made to extrapolate to the likely performance of detectors working at the energy frontier ten years from now.
On the zero crossing of the three-gluon vertex
NASA Astrophysics Data System (ADS)
Athenodorou, A.; Binosi, D.; Boucaud, Ph.; De Soto, F.; Papavassiliou, J.; Rodríguez-Quintero, J.; Zafeiropoulos, S.
2016-10-01
We report on new results on the infrared behavior of the three-gluon vertex in quenched Quantum Chromodynamics, obtained from large-volume lattice simulations. The main focus of our study is the appearance of the characteristic infrared feature known as 'zero crossing', the origin of which is intimately connected with the nonperturbative masslessness of the Faddeev-Popov ghost. The appearance of this effect is clearly visible in one of the two kinematic configurations analyzed, and its theoretical origin is discussed in the framework of Schwinger-Dyson equations. The effective coupling in the momentum subtraction scheme that corresponds to the three-gluon vertex is constructed, revealing the vanishing of the effective interaction at the exact location of the zero crossing.
Vertex topological indices and tree expressions, generalizations of continued fractions
2010-01-01
We expand on the work of Hosoya to describe a generalization of continued fractions called “tree expressions.” Each rooted tree will be shown to correspond to a unique tree expression which can be evaluated as a rational number (not necessarily in lowest terms) whose numerator is equal to the Hosoya index of the entire tree and whose denominator is equal to the tree with the root deleted. In the development, we use Z(G) to define a natural candidate ζ(G, v) for a “vertex topological index” which is a value applied to each vertex of a graph, rather than a value assigned to the graph overall. Finally, we generalize the notion of tree expression to “labeled tree expressions” that correspond to labeled trees and show that such expressions can be evaluated as quotients of determinants of matrices that resemble adjacency matrices. PMID:20490285
Vertex amplitudes in spin foam loop quantum cosmology
NASA Astrophysics Data System (ADS)
Craig, David
2016-03-01
We discuss properties of the vertex expansion for homogeneous, isotropic loop quantum cosmological models sourced by a massless, minimally coupled scalar field, which in this model plays the role of an internal matter ``clock''. We show that the vertex expansion, first written down by Ashtekar, Campiglia and Henderson, must be thought of as a short-time expansion in the sense that the amplitude for volume transitions is constrained both by the order of the expansion and by the elapsed scalar field. To calculate the amplitude for significant volume changes or between large differences in the value of the scalar field requires the expansion be evaluated to very high order. This contribution describes work in collaboration with P. Singh.
An unenumerative DNA computing model for vertex coloring problem.
Xu, Jin; Qiang, Xiaoli; Yang, Yan; Wang, Baoju; Yang, Dongliang; Luo, Liang; Pan, Linqiang; Wang, Shudong
2011-06-01
The solution space exponential explosion caused by the enumeration of the candidate solutions maybe is the biggest obstacle in DNA computing. In the paper, a new unenumerative DNA computing model for graph vertex coloring problem is presented based on two techniques: 1) ordering the vertex sequence for a given graph in such a way that any two consecutive labeled vertices i and i+1 should be adjacent in the graph as much as possible; 2) reducing the number of encodings representing colors according to the construture of the given graph. A graph with 12 vertices without triangles is solved and its initial solution space includes only 283 DNA strands, which is 0.0532 of 3(12) (the worst complexity).
Worldline calculation of the three-gluon vertex
Ahmadiniaz, N.; Schubert, C.
2012-10-23
The three-gluon vertex is a basic object of interest in nonabelian gauge theory. At the one-loop level, it has been calculated and analyzed by a number of authors. Here we use the worldline formalism to unify the calculations of the scalar, spinor and gluon loop contributions to the one-loop vertex, leading to an extremely compact representation in terms of field strength tensors. We verify its equivalence with previously obtained representations, and explain the relation of its structure to the low-energy effective action. The sum rule found by Binger and Brodsky for the scalar, spinor and gluon loop contributions in the present approach relates to worldline supersymmetry.
The SVX II Silicon Vertex Detector at CDF
NASA Astrophysics Data System (ADS)
Valls, Juan A.
1999-08-01
The Silicon VerteX detector (SVX II) for the CDF experiment at the Tevatron p overlinep collider is a 3-barrel 5-layer device with double-sided, AC-coupled silicon strip detectors. The readout is based on a custom IC, the SVX3 chip, capable of simultaneous acquisition, digitization and readout operation (dead-timeless). In this paper we report on the SVX II design and project status including mechanical design, frontend electronics, and data acquisition.
Edge union of networks on the same vertex set
NASA Astrophysics Data System (ADS)
Loe, Chuan Wen; Jeldtoft Jensen, Henrik
2013-06-01
Random network generators such as Erdős-Rényi, Watts-Strogatz and Barabási-Albert models are used as models to study real-world networks. Let G1(V, E1) and G2(V, E2) be two such networks on the same vertex set V. This paper studies the degree distribution and clustering coefficient of the resultant networks, G(V, E1∪E2).
Automatically Generated Algorithms for the Vertex Coloring Problem
Contreras Bolton, Carlos; Gatica, Gustavo; Parada, Víctor
2013-01-01
The vertex coloring problem is a classical problem in combinatorial optimization that consists of assigning a color to each vertex of a graph such that no adjacent vertices share the same color, minimizing the number of colors used. Despite the various practical applications that exist for this problem, its NP-hardness still represents a computational challenge. Some of the best computational results obtained for this problem are consequences of hybridizing the various known heuristics. Automatically revising the space constituted by combining these techniques to find the most adequate combination has received less attention. In this paper, we propose exploring the heuristics space for the vertex coloring problem using evolutionary algorithms. We automatically generate three new algorithms by combining elementary heuristics. To evaluate the new algorithms, a computational experiment was performed that allowed comparing them numerically with existing heuristics. The obtained algorithms present an average 29.97% relative error, while four other heuristics selected from the literature present a 59.73% error, considering 29 of the more difficult instances in the DIMACS benchmark. PMID:23516506
The eight-vertex model with quasi-periodic boundary conditions
NASA Astrophysics Data System (ADS)
Niccoli, G.; Terras, V.
2016-01-01
We study the inhomogeneous eight-vertex model (or equivalently the XYZ Heisenberg spin-1/2 chain) with all kinds of integrable quasi-periodic boundary conditions: periodic, {σ }x-twisted, {σ }y-twisted or {σ }z-twisted. We show that in all these cases but the periodic one with an even number of sites {N}, the transfer matrix of the model is related, by the vertex-IRF transformation, to the transfer matrix of the dynamical six-vertex model with antiperiodic boundary conditions, which we have recently solved by means of Sklyanin's separation of variables approach. We show moreover that, in all the twisted cases, the vertex-IRF transformation is bijective. This allows us to completely characterize, from our previous results on the antiperiodic dynamical six-vertex model, the twisted eight-vertex transfer matrix spectrum (proving that it is simple) and eigenstates. We also consider the periodic case for {N} odd. In this case we can define two independent vertex-IRF transformations, both not bijective, and by using them we show that the eight-vertex transfer matrix spectrum is doubly degenerate, and that it can, as well as the corresponding eigenstates, also be completely characterized in terms of the spectrum and eigenstates of the dynamical six-vertex antiperiodic transfer matrix. In all these cases we can adapt to the eight-vertex case the reformulations of the dynamical six-vertex transfer matrix spectrum and eigenstates that had been obtained by T-Q functional equations, where the Q-functions are elliptic polynomials with twist-dependent quasi-periods. Such reformulations enable one to characterize the eight-vertex transfer matrix spectrum by the solutions of some Bethe-type equations, and to rewrite the corresponding eigenstates as the multiple action of some operators on a pseudo-vacuum state, in a similar way as in the algebraic Bethe ansatz framework.
Anomalous ω-Z-γ vertex from hidden local symmetry
NASA Astrophysics Data System (ADS)
Harada, Masayasu; Matsuzaki, Shinya; Yamawaki, Koichi
2011-08-01
We formulate the general form of the ω-Z-γ vertex in the framework based on the hidden local symmetry, which arises from the gauge-invariant terms for intrinsic parity-odd part of the effective action. Those terms are given as the homogeneous part of the general solution (having free parameters) to the Wess-Zumino anomaly equation and hence are not determined by the anomaly, in sharp contrast to the Harvey-Hill-Hill (HHH) action where the relevant vertex is claimed to be uniquely determined by the anomaly. We show that, even in the framework that HHH was based on, the ω-Z-γ vertex is actually not determined by the anomaly but by the homogeneous (anomaly-free) part of the general solution to the Wess-Zumino anomaly equation having free parameters in the same way as in the hidden local symmetry formulation: The HHH action is just a particular choice of the free parameters in the general solution. We further show that the ω-Z-γ vertex related to the neutrino (ν)-nucleon (N) scattering cross section σ(νN→νN(N')γ) is determined not by the anomaly but by the anomaly-free part of the general solution having free parameters. Nevertheless, we find that the cross section σ(νN→νN(N')γ) is related through the Ward-Takahashi identity to Γ(ω→π0γ) which has the same parameter dependence as that of σ(νN→νN(N')γ) and hence the ratio σ(νN→νN(N')γ)/Γ(ω→π0γ) is fixed independently of these free parameters. Other set of the free parameters of the general solution can be fixed to make the best fit of the ω→π0l+l- process, which substantially differs from the HHH action. This gives a prediction of the cross section σ(νN→νN(N')γ*(l+l-)) to be tested at ν-N collision experiments in the future.
Low-mass materials and vertex detector systems
Cooper, William E.
2014-01-01
Physics requirements set the material budget and the precision and stability necessary in low-mass vertex detector systems. Operational considerations, along with physics requirements, set the operating environment to be provided and determine the heat to be removed. Representative materials for fulfilling those requirements are described and properties of the materials are tabulated. A figure of merit is proposed to aid in material selection. Multi-layer structures are examined as a method to allow material to be used effectively, thereby reducing material contributions. Lastly, comments are made on future directions to be considered in using present materials effectively and in developing new materials.
Low-mass materials and vertex detector systems
Cooper, William E.
2014-01-01
Physics requirements set the material budget and the precision and stability necessary in low-mass vertex detector systems. Operational considerations, along with physics requirements, set the operating environment to be provided and determine the heat to be removed. Representative materials for fulfilling those requirements are described and properties of the materials are tabulated. A figure of merit is proposed to aid in material selection. Multi-layer structures are examined as a method to allow material to be used effectively, thereby reducing material contributions. Lastly, comments are made on future directions to be considered in using present materials effectively and in developing newmore » materials.« less
Vertex Operators Arising from Jacobi-Trudi Identities
NASA Astrophysics Data System (ADS)
Jing, Naihuan; Rozhkovskaya, Natasha
2016-09-01
We give an interpretation of the boson-fermion correspondence as a direct consequence of the Jacobi-Trudi identity. This viewpoint enables us to construct from a generalized version of the Jacobi-Trudi identity the action of a Clifford algebra on the polynomial algebras that arrive as analogues of the algebra of symmetric functions. A generalized Giambelli identity is also proved to follow from that identity. As applications, we obtain explicit formulas for vertex operators corresponding to characters of the classical Lie algebras, shifted Schur functions, and generalized Schur symmetric functions associated to linear recurrence relations.
Three-point vertex functions in Yang-Mills Theory and QCD in Landau gauge
NASA Astrophysics Data System (ADS)
Blum, Adrian L.; Alkofer, Reinhard; Huber, Markus Q.; Windisch, Andreas
2017-03-01
Solutions for the three-gluon and quark-gluon vertices from Dyson-Schwinger equations and the three-particle irreducible formalism are discussed. Dynamical quarks ("unquenching") change the three-gluon vertex via the quark-triangle diagrams which themselves include fully dressed quark-gluon vertex functions. On the other hand, the quark-swordfish diagram is, at least with the model used for the two-quark-two-gluon vertex employed here, of minor importance. For the leading tensor structure of the threegluon vertex the "unquenching" effect can be summarized for the nonperturbative part as a shift of the related dressing function towards the infrared.
NASA Astrophysics Data System (ADS)
Koziel, Michal; Amar-Youcef, Samir; Bialas, Norbert; Deveaux, Michael; Fröhlich, Ingo; Klaus, Philipp; Michel, Jan; Milanović, Borislav; Müntz, Christian; Stroth, Joachim; Tischler, Tobias; Weirich, Roland; Wiebusch, Michael
2017-02-01
The Compressed Baryonic Matter (CBM) Experiment is one of the core experiments of the future FAIR facility near Darmstadt (Germany). The fixed-target experiment will explore the phase diagram of strongly interacting matter in the regime of high net baryon densities with numerous probes, among them open charm mesons. The Micro Vertex Detector (MVD) will provide the secondary vertex resolution of ∼ 50 μm along the beam axis, contribute to the background rejection in dielectron spectroscopy, and to the reconstruction of weak decays. The detector comprises four stations placed at 5, 10, 15, and 20 cm downstream the target and inside the target vacuum. The stations will be populated with highly granular CMOS Monolithic Active Pixel Sensors, which will feature a spatial resolution of < 5 μm, a non-ionizing radiation tolerance of >1013neq /cm2, an ionizing radiation tolerance of ∼ 3 Mrad, and a readout speed of a few 10 μs/frame. This work introduces the MVD-PRESTO project, which aims at integrating a precursor of the second station of the CBM-MVD meeting the following requirements: material budget of x /X0 < 0.5 %, vacuum compatibility, double-sided sensor integration on a Thermal Pyrolytic Graphite (TPG) carrier, and heat evacuation of about 350 mW/cm2/sensor with a temperature gradient of a few K/cm.
Electronics cooling of Phenix multiplicity and vertex detector
Chen, Z.; Gregory, W.S.
1996-08-01
The Multiplicity and Vertex Detector (MVD) uses silicon strip sensors arranged in two concentric barrels around the beam pipe of the PHENIX detector that will be installed at Brookhaven National Laboratory. Each silicon sensor is connected by a flexible kapton cable to its own front-end electronics printed circuit board that is a multi-chip module or MCM. The MCMs are the main heat source in the system. To maintain the MVD at optimized operational status, the maximum temperature of the multi-chip modules must be below 40 C. Using COSMOS/M HSTAR for the Heat Transfer analysis, a finite element model of a typical MCM plate was created to simulate a 9m/s airflow and 9m/s mixed flow composed of 50% helium and 50% air respectively, with convective heat transfer on both sides of the plate. The results using a mixed flow of helium and air show that the average maximum temperature reached by the MCMs is 37.5 C. The maximum temperature which is represented by the hot spots on the MCM is 39.43 C for the helium and air mixture which meets the design temperature requirement 40 C. To maintain the Multiplicity and Vertex Detector at optimized operational status, the configuration of the plenum chamber, the power dissipated by the silicon chips, the fluid flow velocity and comparison on the MCM design parameters will be discussed.
The Belle II silicon vertex detector assembly and mechanics
NASA Astrophysics Data System (ADS)
Adamczyk, K.; Aihara, H.; Angelini, C.; Aziz, T.; Babu, V.; Bacher, S.; Bahinipati, S.; Barberio, E.; Baroncelli, Ti.; Baroncelli, To.; Basith, A. K.; Batignani, G.; Bauer, A.; Behera, P. K.; Bergauer, T.; Bettarini, S.; Bhuyan, B.; Bilka, T.; Bosi, F.; Bosisio, L.; Bozek, A.; Buchsteiner, F.; Bulla, L.; Casarosa, G.; Ceccanti, M.; Červenkov, D.; Chendvankar, S. R.; Dash, N.; Divekar, S. T.; Doležal, Z.; Dutta, D.; Forti, F.; Friedl, M.; Hara, K.; Higuchi, T.; Horiguchi, T.; Irmler, C.; Ishikawa, A.; Jeon, H. B.; Joo, C. W.; Kandra, J.; Kang, K. H.; Kato, E.; Kawasaki, T.; Kodyš, P.; Kohriki, T.; Koike, S.; Kolwalkar, M. M.; Kvasnička, P.; Lanceri, L.; Lettenbicher, J.; Lueck, T.; Maki, M.; Mammini, P.; Mayekar, S. N.; Mohanty, G. B.; Mohanty, S.; Morii, T.; Nakamura, K. R.; Natkaniec, Z.; Negishi, K.; Nisar, N. K.; Onuki, Y.; Ostrowicz, W.; Paladino, A.; Paoloni, E.; Park, H.; Pilo, F.; Profeti, A.; Rashevskaya, I.; Rao, K. K.; Rizzo, G.; Rozanska, M.; Sasaki, J.; Sato, N.; Schultschik, S.; Schwanda, C.; Seino, Y.; Shimizu, N.; Stypula, J.; Suzuki, J.; Tanaka, S.; Tanida, K.; Taylor, G. N.; Thalmeier, R.; Thomas, R.; Tsuboyama, T.; Uozumi, S.; Urquijo, P.; Vitale, L.; Watanuki, S.; Watson, I. J.; Webb, J.; Wiechczynski, J.; Williams, S.; Würkner, B.; Yamamoto, H.; Yin, H.; Yoshinobu, T.
2017-02-01
The Belle II experiment at the asymmetric SuperKEKB collider in Japan will operate at an instantaneous luminosity approximately 50 times greater than its predecessor (Belle). The central feature of the experiment is a vertex detector comprising two layers of pixelated silicon detectors (PXD) and four layers of double-sided silicon microstrip detectors (SVD). One of the key measurements for Belle II is CP violation asymmetry in the decays of beauty and charm hadrons, which hinges on a precise charged-track vertex determination and low-momentum track measurement. Towards this goal, a proper assembly of the SVD components with precise alignment ought to be performed and the geometrical tolerances should be checked to fall within the design limits. We present an overview of the assembly procedure that is being followed, which includes the precision gluing of the SVD module components, wire-bonding of the various electrical components, and precision 3D coordinate measurements of the final SVD modules. Finally, some results from the latest test-beam are reported.
Natural constraints on the gluon-quark vertex
NASA Astrophysics Data System (ADS)
Binosi, Daniele; Chang, Lei; Papavassiliou, Joannis; Qin, Si-Xue; Roberts, Craig D.
2017-02-01
In principle, the strong-interaction sector of the standard model is characterized by a unique renormalization-group-invariant (RGI) running interaction and a unique form for the dressed-gluon-quark vertex, Γμ; but, whilst much has been learnt about the former, the latter is still obscure. In order to improve this situation, we use a RGI running-interaction that reconciles top-down and bottom-up analyses of the gauge sector in quantum chromodynamics (QCD) to compute dressed-quark gap equation solutions with 1,660,000 distinct Ansätze for Γμ. Each one of the solutions is then tested for compatibility with three physical criteria and, remarkably, we find that merely 0.55% of the solutions survive the test. Evidently, even a small selection of observables places extremely tight bounds on the domain of realistic vertex Ansätze. This analysis and its results should prove useful in constraining insightful contemporary studies of QCD and hadronic phenomena.
Quark-gluon vertex: A perturbation theory primer and beyond
NASA Astrophysics Data System (ADS)
Bermudez, R.; Albino, L.; Gutiérrez-Guerrero, L. X.; Tejeda-Yeomans, M. E.; Bashir, A.
2017-02-01
There has been growing evidence that the infrared enhancement of the form factors defining the full quark-gluon vertex plays an important role in realizing a dynamical breakdown of chiral symmetry in quantum chromodynamics, leading to the observed spectrum and properties of hadrons. Both the lattice and the Schwinger-Dyson communities have begun to calculate these form factors in various kinematical regimes of momenta involved. A natural consistency check for these studies is that they should match onto the perturbative predictions in the ultraviolet, where nonperturbative effects mellow down. In this article, we carry out a numerical analysis of the one-loop result for all the form factors of the quark-gluon vertex. Interestingly, even the one-loop results qualitatively encode most of the infrared enhancement features expected of their nonperturbative counter parts. We analyze various kinematical configurations of momenta: symmetric, on shell, and asymptotic. The on-shell limit enables us to compute anomalous chromomagnetic moment of quarks. The asymptotic results have implications for the multiplicative renormalizability of the quark propagator and its connection with the Landau-Khalatnikov-Fradkin transformations, allowing us to analyze and compare various Ansätze proposed so far.
Heavy flavour physics at colliders with silicon strip vertex detectors
NASA Astrophysics Data System (ADS)
Schwarz, Andreas S.
1994-03-01
The physics of heavy flavours has played a dominant role in high energy physics research ever since the discovery of charm in 1974, followed by the τ lepton in 1975 and bottom in 1977. With the startup of the large experiments at the e+e- colliders LEP and the SLC a new type of detector system has now come into operation which has a major impact on the studies of heavy flavours: the silicon strip vertex detector. The basic design priciples of these novel detector systems are outlined and three representative experimental realizations are discussed. The impact of these detectors on the studies of the properties of heavy flavours is just emerging and focuses on the measurement of lifetimes and the tagging of the presence of heavy flavour hadrons in hadronic events. The tools that are being developed for these studies are described as well as details of representative analyses. The potential of these devices and the associated technological developments that were necessary for their application in the colding beam environment is reflected in a plethora of new proposals to build sophisticated silicon detector systems for a large variety of future high energy physics applications. Two examples will be briefly sketched, a vertex detector for an asymmetric e+e- bottom factory and a large scale tracking system for a multipurpose detector at one of the new large hadron colliders.
NASA Astrophysics Data System (ADS)
Janiš, Václav; Pokorný, Vladislav
2012-12-01
We propose a renormalization scheme of the Kubo formula for the electrical conductivity with multiple backscatterings contributing to the electron-hole irreducible vertex derived from the asymptotic limit to high spatial dimensions. We use this vertex to represent the two-particle Green function via a symmetrized Bethe-Salpeter equation in momentum space. We further utilize the dominance of a pole in the irreducible vertex to an approximate diagonalization of the Bethe-Salpeter equation and a non-perturbative representation of the electron-hole correlation function. The latter function is then used to derive a compact representation for the electrical conductivity at zero temperature without the necessity to evaluate separately the Drude term and vertex corrections. The electrical conductivity calculated in this way remains nonnegative also in the strongly disordered regime where the localization effects become significant and the negative vertex corrections in the standard Kubo formula overweight the Drude term.
The scalar-photon 3-point vertex in massless quenched scalar QED
NASA Astrophysics Data System (ADS)
Concha-Sánchez, Y.; Gutiérrez-Guerrero, L. X.; Fernández-Rangel, L. A.
2016-10-01
Non perturbative studies of Schwinger-Dyson equations (SDEs) require their infinite, coupled tower to be truncated in order to reduce them to a practically solvable set. In this connection, a physically acceptable ansatz for the three point vertex is the most favorite choice. Scalar quantum electrodynamics (sQED) provides a simple and neat platform to address this problem. The most general form of the scalar-photon three point vertex can be expressed in terms of only two independent form factors, longitudinal and transverse. Ball and Chiu have demonstrated that the longitudinal vertex is fixed by requiring the Ward-Fradkin-Green- Takahashi identity (WFGTI), while the transverse vertex remains undetermined. In massless quenched sQED, we propose the transverse part of the non perturbative scalar-photon vertex.
The silicon vertex detector of the Belle II experiment
NASA Astrophysics Data System (ADS)
Adamczyk, K.; Aihara, H.; Angelini, C.; Aziz, T.; Babu, V.; Bacher, S.; Bahinipati, S.; Barberio, E.; Baroncelli, T.; Basith, A. K.; Batignani, G.; Bauer, A.; Behera, P. K.; Bergauer, T.; Bettarini, S.; Bhuyan, B.; Bilka, T.; Bosi, F.; Bosisio, L.; Bozek, A.; Buchsteiner, F.; Casarosa, G.; Ceccanti, M.; Červenkov, D.; Chendvankar, S. R.; Dash, N.; Divekar, S. T.; Doležal, Z.; Dutta, D.; Forti, F.; Friedl, M.; Hara, K.; Higuchi, T.; Horiguchi, T.; Irmler, C.; Ishikawa, A.; Jeon, H. B.; Joo, C. W.; Kandra, J.; Kang, K. H.; Kato, E.; Kawasaki, T.; Kodyš, P.; Kohriki, T.; Koike, S.; Kolwalkar, M. M.; Kvasnička, P.; Lanceri, L.; Lettenbicher, J.; Mammini, P.; Mayekar, S. N.; Mohanty, G. B.; Mohanty, S.; Morii, T.; Nakamura, K. R.; Natkaniec, Z.; Negishi, K.; Nisar, N. K.; Onuki, Y.; Ostrowicz, W.; Paladino, A.; Paoloni, E.; Park, H.; Pilo, F.; Profeti, A.; Rao, K. K.; Rashevskaya, I.; Rizzo, G.; Rozanska, M.; Sandilya, S.; Sasaki, J.; Sato, N.; Schultschik, S.; Schwanda, C.; Seino, Y.; Shimizu, N.; Stypula, J.; Tanaka, S.; Tanida, K.; Taylor, G. N.; Thalmeier, R.; Thomas, R.; Tsuboyama, T.; Uozumi, S.; Urquijo, P.; Vitale, L.; Volpi, M.; Watanuki, S.; Watson, I. J.; Webb, J.; Wiechczynski, J.; Williams, S.; Würkner, B.; Yamamoto, H.; Yin, H.; Yoshinobu, T.
2016-07-01
The silicon vertex detector of the Belle II experiment, structured in a lantern shape, consists of four layers of ladders, fabricated from two to five silicon sensors. The APV25 readout ASIC chips are mounted on one side of the ladder to minimize the signal path for reducing the capacitive noise; signals from the sensor backside are transmitted to the chip by bent flexible fan-out circuits. The ladder is assembled using several dedicated jigs. Sensor motion on the jig is minimized by vacuum chucking. The gluing procedure provides such a rigid foundation that later leads to the desired wire bonding performance. The full ladder with electrically functional sensors is consistently completed with a fully developed assembly procedure, and its sensor offsets from the design values are found to be less than 200 μm. The potential functionality of the ladder is also demonstrated by the radioactive source test.
A vertex similarity index for better personalized recommendation
NASA Astrophysics Data System (ADS)
Chen, Ling-Jiao; Zhang, Zi-Ke; Liu, Jin-Hu; Gao, Jian; Zhou, Tao
2017-01-01
Recommender systems benefit us in tackling the problem of information overload by predicting our potential choices among diverse niche objects. So far, a variety of personalized recommendation algorithms have been proposed and most of them are based on similarities, such as collaborative filtering and mass diffusion. Here, we propose a novel vertex similarity index named CosRA, which combines advantages of both the cosine index and the resource-allocation (RA) index. By applying the CosRA index to real recommender systems including MovieLens, Netflix and RYM, we show that the CosRA-based method has better performance in accuracy, diversity and novelty than some benchmark methods. Moreover, the CosRA index is free of parameters, which is a significant advantage in real applications. Further experiments show that the introduction of two turnable parameters cannot remarkably improve the overall performance of the CosRA index.
Performance of the CLAS12 Silicon Vertex Tracker modules
Antonioli, Mary Ann; Boiarinov, Serguie; Bonneau, Peter R.; Elouadrhiri, Latifa; Eng, Brian J.; Gotra, Yuri N.; Kurbatov, Evgeny O.; Leffel, Mindy A.; Mandal, Saptarshi; McMullen, Marc E.; Merkin, Mikhail M.; Raydo, Benjamin J.; Teachey, Robert W,; Tucker, Ross J.; Ungaro, Maurizio; Yegneswaran, Amrit S.; Ziegler, Veronique
2013-12-01
For the 12 GeV upgrade, the CLAS12 experiment has designed a Silicon Vertex Tracker (SVT) using single sided microstrip sensors fabricated by Hamamatsu. The sensors have graded angle design to minimize dead areas and a readout pitch of 156{micro}m, with intermediate strip. Double sided SVT module hosts three daisy-chained sensors on each side with a full strip length of 33 cm. There are 512 channels per module read out by four Fermilab Silicon Strip Readout (FSSR2) chips featuring data driven architecture, mounted on a rigid-flex hybrid. Modules are assembled on the barrel using unique cantilevered geometry to minimize the amount of material in the tracking volume. Design and performance of the SVT modules are presented, focusing on results of electrical measurements.
Performance of the CLAS12 Silicon Vertex Tracker modules
NASA Astrophysics Data System (ADS)
Antonioli, M. A.; Boiarinov, S.; Bonneau, P.; Elouadrhiri, L.; Eng, B.; Gotra, Y.; Kurbatov, E.; Leffel, M.; Mandal, S.; McMullen, M.; Merkin, M.; Raydo, B.; Teachey, W.; Tucker, R.; Ungaro, M.; Yegneswaran, A.; Ziegler, V.
2013-12-01
For the 12 GeV upgrade, the CLAS12 experiment has designed a Silicon Vertex Tracker (SVT) using single sided microstrip sensors fabricated by Hamamatsu. The sensors have graded angle design to minimize dead areas and a readout pitch of 156 μm, with intermediate strip. Double sided SVT module hosts three daisy-chained sensors on each side with a full strip length of 33 cm. There are 512 channels per module read out by four Fermilab Silicon Strip Readout (FSSR2) chips featuring data driven architecture, mounted on a rigid-flex hybrid. Modules are assembled on the barrel using unique cantilevered geometry to minimize the amount of material in the tracking volume. Design and performance of the SVT modules are presented, focusing on results of electrical measurements.
Cutaneous paraganglioma of the vertex in a child.
Kim; Lee, Il Jae; Park, Myong Chul; Kim, Joo Hyoung; Lim, Hyoseob
2012-07-01
Paraganglioma is a neuroendocrine neoplasm that may develop at various body sites, including the head, neck, thorax, and abdomen. Approximately 85% of paragangliomas develop on the abdomen, 12% develop on the chest, and only 3% develop on the head and neck. These tumors are found in locations that parallel the sympathetic chain ganglion in the thoracolumbar regions and parasympathetic nervous system in craniosacral regions, and all head and neck paragangliomas arise from the parasympathetic nervous system. Although the skin has a rich neural network, it is devoid of ganglia. There has been only 1 report of a paraganglioma on the scalp of a child. We describe a 3-year-old child with a primary cutaneous paraganglioma of the vertex scalp and review the literature on paragangliomas.
Displaced vertex searches for sterile neutrinos at future lepton colliders
NASA Astrophysics Data System (ADS)
Antusch, Stefan; Cazzato, Eros; Fischer, Oliver
2016-12-01
We investigate the sensitivity of future lepton colliders to displaced vertices from the decays of long-lived heavy (almost sterile) neutrinos with electroweak scale masses and detectable time of flight. As future lepton colliders we consider the FCC-ee, the CEPC, and the ILC, searching at the Z-pole and at the center-of-mass energies of 240, 350 and 500 GeV. For a realistic discussion of the detector response to the displaced vertex signal and the Standard Model background we consider the ILC's Silicon Detector (SiD) as benchmark for the future lepton collider detectors. We find that displaced vertices constitute a powerful search channel for sterile neutrinos, sensitive to squared active-sterile mixing angles as small as 10-11.
Limits on anomalous contributions to the Wtb vertex
NASA Astrophysics Data System (ADS)
Pease, Christopher; Fiolhais, Miguel; Onofre, Antonio
2017-01-01
Recent LHC results on the measurements of the W-boson helicity fractions and single top quark production cross section at a center-of-mass energy of 13 TeV are combined in order to establish new limits on anomalous contributions to the Wtb vertex. The allowed regions for these limits are presented in three-dimensional graphics, for both real and imaginary components of the different anomalous couplings, allowing all the other anomalous couplings to vary at the same time. These results are combined with the prospected future measurement of the single top quark production cross section and W-boson helicity fractions at the LHC. When compared with the previous most precise limits, these results show a significant improvement, larger than 10%.
The FIRST experiment: interaction region and MAPS vertex detector
NASA Astrophysics Data System (ADS)
Spiriti, E.; de Napoli, M.; Romano, F.; FIRST Collaboration
2011-06-01
The improvement of the precision of the measurement of the nuclear cross-section, in order to fulfill the requirements of the actual Monte Carlo simulations for hadrontherapy and space radioprotection, is the main goal of the FIRST experiment. After a brief introduction on the treatment planning in hadrontherapy, this paper describes main characteristics and components of the experiment. The features of the interaction region detectors and their main needs (low material budget, high angular coverage, two tracks resolution and large trigger rate) are discussed. Special emphasis is devoted in discussing the new silicon pixel vertex detector, in particular its new developed data acquisition and its characterization with the first test results obtained with a prototype of the detector.
Small Vertex Cover Makes Petri Net Coverability and Boundedness Easier
NASA Astrophysics Data System (ADS)
Praveen, M.
The coverability and boundedness problems for Petri nets are known to be Expspace-complete. Given a Petri net, we associate a graph with it. With the vertex cover number k of this graph and the maximum arc weight W as parameters, we show that coverability and boundedness are in ParaPspace. This means that these problems can be solved in space O(ef(k,W)poly(n)) where ef(k,W) is some exponential function and poly(n) is some polynomial in the size of the input. We then extend the ParaPspace result to model checking a logic that can express some generalizations of coverability and boundedness.
Vertex Sensitivity in the Schwinger-Dyson Equations of QCD
David J. Wilson, Michael R. Pennington
2012-01-01
The nonperturbative gluon and ghost propagators in Landau gauge QCD are obtained using the Schwinger-Dyson equation approach. The propagator equations are solved in Euclidean space using Landau gauge with a range of vertex inputs. Initially we solve for the ghost alone, using a model gluon input, which leads us to favour a finite ghost dressing in the nonperturbative region. In order to then solve the gluon and ghost equations simultaneously, we find that non-trivial vertices are required, particularly for the gluon propagator in the small momentum limit. We focus on the properties of a number vertices and how these differences influence the final solutions. The self-consistent solutions we obtain are all qualitatively similar and contain a mass-like term in the gluon propagator dressing in agreement with related studies, supporting the long-held proposal of Cornwall.
The LHCb Vertex Locator (VELO) Pixel Detector Upgrade
NASA Astrophysics Data System (ADS)
Buchanan, E.
2017-01-01
The LHCb experiment is designed to perform high-precision measurements of CP violation and the decays of beauty and charm hadrons at the Large Hadron Collider (LHC) at CERN. There is a planned upgrade during Long Shutdown 2 (LS2), expected in 2019, which will allow the detector to run at higher luminosities by transforming the entire readout to a trigger-less system. This will include a substantial upgrade of the Vertex Locator (VELO), the silicon tracker that surrounds the LHCb interaction region. The VELO is moving from silicon strip technology to hybrid pixel sensors, where silicon sensors are bonded to VeloPix ASICs. Sensor prototypes have undergone rigorous testing using the Timepix3 Telescope at the SPS, CERN. The main components of the upgrade are summarised and testbeam results presented.
Photoabsorption off nuclei with self-consistent vertex corrections
Riek, F.; Lutz, M. F. M.; Korpa, C. L.
2009-08-15
We study photoproduction off nuclei based on a self-consistent and covariant many-body approach for the pion and isobar propagation in infinite nuclear matter. For the first time the t-channel exchange of an in-medium pion is evaluated in the presence of vertex correction effects consistently. In particular the interference pattern with the s-channel in-medium nucleon and isobar exchange contribution is considered. Electromagnetic gauge invariance is kept as a consequence of various Ward identities obeyed by the computation. Adjusting the set of Migdal parameters to the data set we predict an attractive mass shift for the isobar of about 50 MeV at nuclear saturation density.
A high-order vertex-based central ENO finite-volume scheme for three-dimensional compressible flows
Charest, Marc R.J.; Canfield, Thomas R.; Morgan, Nathaniel R.; ...
2015-03-11
High-order discretization methods offer the potential to reduce the computational cost associated with modeling compressible flows. However, it is difficult to obtain accurate high-order discretizations of conservation laws that do not produce spurious oscillations near discontinuities, especially on multi-dimensional unstructured meshes. A novel, high-order, central essentially non-oscillatory (CENO) finite-volume method that does not have these difficulties is proposed for tetrahedral meshes. The proposed unstructured method is vertex-based, which differs from existing cell-based CENO formulations, and uses a hybrid reconstruction procedure that switches between two different solution representations. It applies a high-order k-exact reconstruction in smooth regions and a limited linearmore » reconstruction when discontinuities are encountered. Both reconstructions use a single, central stencil for all variables, making the application of CENO to arbitrary unstructured meshes relatively straightforward. The new approach was applied to the conservation equations governing compressible flows and assessed in terms of accuracy and computational cost. For all problems considered, which included various function reconstructions and idealized flows, CENO demonstrated excellent reliability and robustness. Up to fifth-order accuracy was achieved in smooth regions and essentially non-oscillatory solutions were obtained near discontinuities. The high-order schemes were also more computationally efficient for high-accuracy solutions, i.e., they took less wall time than the lower-order schemes to achieve a desired level of error. In one particular case, it took a factor of 24 less wall-time to obtain a given level of error with the fourth-order CENO scheme than to obtain the same error with the second-order scheme.« less
A high-order vertex-based central ENO finite-volume scheme for three-dimensional compressible flows
Charest, Marc R.J.; Canfield, Thomas R.; Morgan, Nathaniel R.; Waltz, Jacob; Wohlbier, John G.
2015-03-11
High-order discretization methods offer the potential to reduce the computational cost associated with modeling compressible flows. However, it is difficult to obtain accurate high-order discretizations of conservation laws that do not produce spurious oscillations near discontinuities, especially on multi-dimensional unstructured meshes. A novel, high-order, central essentially non-oscillatory (CENO) finite-volume method that does not have these difficulties is proposed for tetrahedral meshes. The proposed unstructured method is vertex-based, which differs from existing cell-based CENO formulations, and uses a hybrid reconstruction procedure that switches between two different solution representations. It applies a high-order k-exact reconstruction in smooth regions and a limited linear reconstruction when discontinuities are encountered. Both reconstructions use a single, central stencil for all variables, making the application of CENO to arbitrary unstructured meshes relatively straightforward. The new approach was applied to the conservation equations governing compressible flows and assessed in terms of accuracy and computational cost. For all problems considered, which included various function reconstructions and idealized flows, CENO demonstrated excellent reliability and robustness. Up to fifth-order accuracy was achieved in smooth regions and essentially non-oscillatory solutions were obtained near discontinuities. The high-order schemes were also more computationally efficient for high-accuracy solutions, i.e., they took less wall time than the lower-order schemes to achieve a desired level of error. In one particular case, it took a factor of 24 less wall-time to obtain a given level of error with the fourth-order CENO scheme than to obtain the same error with the second-order scheme.
Quark-gluon vertex dressing and meson masses beyond ladder-rainbow truncation
Hrayr Matevosyan; Anthony Thomas; Peter Tandy
2007-04-01
We include a generalized infinite class of quark-gluon vertex dressing diagrams in a study of how dynamics beyond the ladder-rainbow truncation influences the Bethe-Salpeter description of light quark pseudoscalar and vector mesons. The diagrammatic specification of the vertex is mapped into a corresponding specification of the Bethe-Salpeter kernel, which preserves chiral symmetry. This study adopts the algebraic format afforded by the simple interaction kernel used in previous work on this topic. The new feature of the present work is that in every diagram summed for the vertex and the corresponding Bethe-Salpeter kernel, each quark-gluon vertex is required to be the self-consistent vertex solution. We also adopt from previous work the effective accounting for the role of the explicitly non-Abelian three gluon coupling in a global manner through one parameter determined from recent lattice-QCD data for the vertex. With the more consistent vertex used here, the error in ladder-rainbow truncation for vector mesons is never more than 10% as the current quark mass is varied from the u/d region to the b region.
Quark-gluon vertex dressing and meson masses beyond ladder-rainbow truncation
Matevosyan, Hrayr H.; Thomas, Anthony W.; Tandy, Peter C.
2007-04-15
We include a generalized infinite class of quark-gluon vertex dressing diagrams in a study of how dynamics beyond the ladder-rainbow truncation influences the Bethe-Salpeter description of light-quark pseudoscalar and vector mesons. The diagrammatic specification of the vertex is mapped into a corresponding specification of the Bethe-Salpeter kernel, which preserves chiral symmetry. This study adopts the algebraic format afforded by the simple interaction kernel used in previous work on this topic. The new feature of the present work is that in every diagram summed for the vertex and the corresponding Bethe-Salpeter kernel, each quark-gluon vertex is required to be the self-consistent vertex solution. We also adopt from previous work the effective accounting for the role of the explicitly non-Abelian three-gluon coupling in a global manner through one parameter determined from recent lattice-QCD data for the vertex. Within the current model, the more consistent dressed vertex limits the ladder-rainbow truncation error for vector mesons to be never more than 10% as the current quark mass is varied from the u/d region to the b region.
Characterizing general scale-free networks by vertex-degree sequences
NASA Astrophysics Data System (ADS)
Xiao, Wenjun; Lai, Zhengwen; Chen, Guanrong
2015-11-01
Many complex networks possess a scale-free vertex-degree distribution in a power-law form of c k-γ , where k is the vertex-degree variable and c and γ are constants. To better understand the mechanism of the power-law formation in scale-free networks, it is important to understand and analyze their vertex-degree sequences. We had shown before that, for a scale-free network of size N , if its vertex-degree sequence is k1
Quark-gluon vertex dressing and meson masses beyond ladder-rainbow truncation
NASA Astrophysics Data System (ADS)
Matevosyan, Hrayr H.; Thomas, Anthony W.; Tandy, Peter C.
2007-04-01
We include a generalized infinite class of quark-gluon vertex dressing diagrams in a study of how dynamics beyond the ladder-rainbow truncation influences the Bethe-Salpeter description of light-quark pseudoscalar and vector mesons. The diagrammatic specification of the vertex is mapped into a corresponding specification of the Bethe-Salpeter kernel, which preserves chiral symmetry. This study adopts the algebraic format afforded by the simple interaction kernel used in previous work on this topic. The new feature of the present work is that in every diagram summed for the vertex and the corresponding Bethe-Salpeter kernel, each quark-gluon vertex is required to be the self-consistent vertex solution. We also adopt from previous work the effective accounting for the role of the explicitly non-Abelian three-gluon coupling in a global manner through one parameter determined from recent lattice-QCD data for the vertex. Within the current model, the more consistent dressed vertex limits the ladder-rainbow truncation error for vector mesons to be never more than 10% as the current quark mass is varied from the u/d region to the b region.
The MAPS-based vertex detector for the STAR experiment: Lessons learned and performance
NASA Astrophysics Data System (ADS)
Contin, Giacomo
2016-09-01
The PiXeL detector (PXL) of the STAR experiment at RHIC is the first application of the state-of-the-art thin Monolithic Active Pixel Sensors (MAPS) technology in a collider environment. The PXL, together with the Intermediate Silicon Tracker (IST) and the Silicon Strip Detector (SSD), form the Heavy Flavor Tracker (HFT), which has been designed to improve the vertex resolution and extend the STAR measurement capabilities in the heavy flavor domain, providing a clean probe for studying the Quark-Gluon Plasma. The two PXL layers are placed at a radius of 2.8 and 8 cm from the beam line, respectively, and is based on ultra-thin high resolution MAPS sensors. The sensor features 20.7 μm pixel pitch, 185.6 μs readout time and 170 mW/cm2 power dissipation. The detector is air-cooled, allowing a global material budget of 0.4% radiation length on the innermost layer. A novel mechanical approach to detector insertion allows for fast installation and integration of the pixel sub detector. The HFT took data in Au+Au collisions at 200 GeV during the 2014 RHIC run. Modified during the RHIC shutdown to improve its reliability, material budget, and tracking capabilities, the HFT took data in p+p and p+Au collisions at √sNN=200 GeV in the 2015 RHIC run. In this paper we present detector specifications, experience from the construction and operations, and lessons learned. We also show preliminary results from 2014 Au+Au data analyses, demonstrating the capabilities of charm reconstruction with the HFT.
Novel integrated CMOS pixel structures for vertex detectors
Kleinfelder, Stuart; Bieser, Fred; Chen, Yandong; Gareus, Robin; Matis, Howard S.; Oldenburg, Markus; Retiere, Fabrice; Ritter, Hans Georg; Wieman, Howard H.; Yamamoto, Eugene
2003-10-29
Novel CMOS active pixel structures for vertex detector applications have been designed and tested. The overriding goal of this work is to increase the signal to noise ratio of the sensors and readout circuits. A large-area native epitaxial silicon photogate was designed with the aim of increasing the charge collected per struck pixel and to reduce charge diffusion to neighboring pixels. The photogate then transfers the charge to a low capacitance readout node to maintain a high charge to voltage conversion gain. Two techniques for noise reduction are also presented. The first is a per-pixel kT/C noise reduction circuit that produces results similar to traditional correlated double sampling (CDS). It has the advantage of requiring only one read, as compared to two for CDS, and no external storage or subtraction is needed. The technique reduced input-referred temporal noise by a factor of 2.5, to 12.8 e{sup -}. Finally, a column-level active reset technique is explored that suppresses kT/C noise during pixel reset. In tests, noise was reduced by a factor of 7.6 times, to an estimated 5.1 e{sup -} input-referred noise. The technique also dramatically reduces fixed pattern (pedestal) noise, by up to a factor of 21 in our tests. The latter feature may possibly reduce pixel-by-pixel pedestal differences to levels low enough to permit sparse data scan without per-pixel offset corrections.
CDF Run IIb Silicon Vertex Detector DAQ Upgrade
S. Behari et al.
2003-12-18
The CDF particle detector operates in the beamline of the Tevatron proton-antiproton collider at Fermilab, Batavia, IL. The Tevatron is expected to undergo luminosity upgrades (Run IIb) in the future, resulting in a higher number of interactions per beam crossing. To operate in this dense radiation environment, an upgrade of CDF's silicon vertex detector (SVX) subsystem and a corresponding upgrade of its VME-based DAQ system has been explored. Prototypes of all the Run IIb SVX DAQ components have been constructed, assembled into a test stand and operated successfully using an adapted version of CDF's network-capable DAQ software. In addition, a PCI-based DAQ system has been developed as a fast and inexpensive tool for silicon detector and DAQ component testing in the production phase. In this paper they present an overview of the Run IIb silicon DAQ upgrade, emphasizing the new features and improvements incorporated into the constituent VME boards, and discuss a PCI-based DAQ system developed to facilitate production tests.
From vertex detectors to inner trackers with CMOS pixel sensors
NASA Astrophysics Data System (ADS)
Besson, A.; Pérez, A. Pérez; Spiriti, E.; Baudot, J.; Claus, G.; Goffe, M.; Winter, M.
2017-02-01
The use of CMOS Pixel Sensors (CPS) for high resolution and low material vertex detectors has been validated with the 2014 and 2015 physics runs of the STAR-PXL detector at RHIC/BNL. This opens the door to the use of CPS for inner tracking devices, with 10-100 times larger sensitive area, which require therefore a sensor design privileging power saving, response uniformity and robustness. The 350 nm CMOS technology used for the STAR-PXL sensors was considered as too poorly suited to upcoming applications like the upgraded ALICE Inner Tracking System (ITS), which requires sensors with one order of magnitude improvement on readout speed and improved radiation tolerance. This triggered the exploration of a deeper sub-micron CMOS technology, Tower-Jazz 180 nm, for the design of a CPS well adapted for the new ALICE-ITS running conditions. This paper reports the R & D results for the conception of a CPS well adapted for the ALICE-ITS.
Fast unmixing of multispectral optoacoustic data with vertex component analysis
NASA Astrophysics Data System (ADS)
Luís Deán-Ben, X.; Deliolanis, Nikolaos C.; Ntziachristos, Vasilis; Razansky, Daniel
2014-07-01
Multispectral optoacoustic tomography enhances the performance of single-wavelength imaging in terms of sensitivity and selectivity in the measurement of the biodistribution of specific chromophores, thus enabling functional and molecular imaging applications. Spectral unmixing algorithms are used to decompose multi-spectral optoacoustic data into a set of images representing distribution of each individual chromophoric component while the particular algorithm employed determines the sensitivity and speed of data visualization. Here we suggest using vertex component analysis (VCA), a method with demonstrated good performance in hyperspectral imaging, as a fast blind unmixing algorithm for multispectral optoacoustic tomography. The performance of the method is subsequently compared with a previously reported blind unmixing procedure in optoacoustic tomography based on a combination of principal component analysis (PCA) and independent component analysis (ICA). As in most practical cases the absorption spectrum of the imaged chromophores and contrast agents are known or can be determined using e.g. a spectrophotometer, we further investigate the so-called semi-blind approach, in which the a priori known spectral profiles are included in a modified version of the algorithm termed constrained VCA. The performance of this approach is also analysed in numerical simulations and experimental measurements. It has been determined that, while the standard version of the VCA algorithm can attain similar sensitivity to the PCA-ICA approach and have a robust and faster performance, using the a priori measured spectral information within the constrained VCA does not generally render improvements in detection sensitivity in experimental optoacoustic measurements.
A dynamic cellular vertex model of growing epithelial tissues
NASA Astrophysics Data System (ADS)
Lin, Shao-Zhen; Li, Bo; Feng, Xi-Qiao
2017-03-01
Intercellular interactions play a significant role in a wide range of biological functions and processes at both the cellular and tissue scales, for example, embryogenesis, organogenesis, and cancer invasion. In this paper, a dynamic cellular vertex model is presented to study the morphomechanics of a growing epithelial monolayer. The regulating role of stresses in soft tissue growth is revealed. It is found that the cells originating from the same parent cell in the monolayer can orchestrate into clustering patterns as the tissue grows. Collective cell migration exhibits a feature of spatial correlation across multiple cells. Dynamic intercellular interactions can engender a variety of distinct tissue behaviors in a social context. Uniform cell proliferation may render high and heterogeneous residual compressive stresses, while stress-regulated proliferation can effectively release the stresses, reducing the stress heterogeneity in the tissue. The results highlight the critical role of mechanical factors in the growth and morphogenesis of epithelial tissues and help understand the development and invasion of epithelial tumors.
A spin glass approach to the directed feedback vertex set problem
NASA Astrophysics Data System (ADS)
Zhou, Hai-Jun
2016-07-01
A directed graph (digraph) is formed by vertices and arcs (directed edges) from one vertex to another. A feedback vertex set (FVS) is a set of vertices that contains at least one vertex of every directed cycle in this digraph. The directed feedback vertex set problem aims at constructing a FVS of minimum cardinality. This is a fundamental cycle-constrained hard combinatorial optimization problem with wide practical applications. In this paper we construct a spin glass model for the directed FVS problem by converting the global cycle constraints into local arc constraints, and study this model through the replica-symmetric (RS) mean field theory of statistical physics. We then implement a belief propagation-guided decimation (BPD) algorithm for single digraph instances. The BPD algorithm slightly outperforms the simulated annealing algorithm on large random graph instances. The RS mean field results and algorithmic results can be further improved by working on a more restrictive (and more difficult) spin glass model.
Hubble Space Telescope secondary mirror vertex radius/conic constant test
NASA Technical Reports Server (NTRS)
Parks, Robert
1991-01-01
The Hubble Space Telescope backup secondary mirror was tested to determine the vertex radius and conic constant. Three completely independent tests (to the same procedure) were performed. Similar measurements in the three tests were highly consistent. The values obtained for the vertex radius and conic constant were the nominal design values within the error bars associated with the tests. Visual examination of the interferometric data did not show any measurable zonal figure error in the secondary mirror.
Salgado, Christopher J.; Chim, Harvey; Tang, Jennifer C.; Monstrey, Stan J.; Mardini, Samir
2011-01-01
A variety of surgical options exists for penile reconstruction. The key to success of therapy is holistic management of the patient, with attention to the psychological aspects of treatment. In this article, we review reconstructive modalities for various types of penile defects inclusive of partial and total defects as well as the buried penis, and also describe recent basic science advances, which may promise new options for penile reconstruction. PMID:22851914
TECHNICAL DESIGN REPORT OF THE FORWARD SILICON VERTEX (FVTX)
PHENIX EXPERIMENT; OBRIEN,E.; PAK, R.; DREES, K.A.
2007-08-01
The main goal of the RHIC heavy ion program is the discovery of the novel ultra-hot high-density state of matter predicted by the fundamental theory of strong interactions and created in collisions of heavy nuclei, the Quark-Gluon Plasma (QGP). From measurements of the large elliptic flow of light mesons and baryons and their large suppression at high transverse momentum pT that have been made at RHIC, there is evidence that new degrees of freedom, characteristic of a deconfined QCD medium, drive the dynamics of nucleus-nucleus collisions. It has been recognized, however, that the potential of light quarks and gluons to characterize the properties of the QGP medium is limited and the next phase of the RHIC program calls for the precise determination of its density, temperature, opacity and viscosity using qualitatively new probes, such as heavy quarks. We propose the construction of two Forward Silicon Vertex Trackers (FVTX) for the PHENIX experiment that will directly identify and distinguish charm and beauty decays within the acceptance of the muon spectrometers. The FVTX will provide this essential coverage over a range of forward and backward rapidities (1.2 < |y| < 2.4)--a rapidity range coverage which not only brings significantly larger acceptance to PHENIX but which is critical for separating cold nuclear matter effects from QGP effects and is critical for measuring the proton spin contributions over a significant fraction of the kinematic range of interest. In addition, the FVTX will provide greatly reduced background and improved mass resolution for dimuon events, culminating in the first measurements of the {upsilon}{prime} and Drell-Yan at RHIC. These same heavy flavor and dimuon measurements in p+p collisions will allow us to place significant constraints on the gluon and sea quark contributions to the proton's spin and to make fundamentally new tests of the Sivers function universality.
VERTEX: Manganese transport with CaCO 3
NASA Astrophysics Data System (ADS)
Martin, John H.; Knauer, George A.
1983-04-01
Manganese transport was studied off central California in August and September 1981 as part of the VERTEX (Vertica l Transport and Exchange) research program. Refractory, leachable, and dissolved Mn fractions associated with particles caught in traps set at 11 depths (50 to 2000 m) were analyzed. Through intentional and unintentional CaCO 3 dissolution 'experiments', it was learned that the weakly leachable Mn was originally in association with the carbonate phase. Adsorption on surfaces rather than absorption in CaCO 3 matrices was indicated by the finding that Mn was not released in proportion to the CaCo 3 dissolved, instead it appeared to keep readsorbing to the dissolving surface. Ultimately, Mn went into solution when the particulate CaCO 3 was essentially depleted, suggesting that sufficient sites for adsorption were no longer available. Manganese fluxes with CaCO 3 were low near the surface (0.1 mg cm -2 ky -1), but increased rapidly in the 50 to 200-m depth interval, and then became more or less constant (1.3 mg cm -2 ky -1 for the remainder of the water column (300 to 2000 m). Rate-of-change estimates indicate that Mn is rapidly scavenged in near-surface waters (-130 ng 1 -1 y -1) and slowly regenerated at depth (2.7 ng 1 -1 y -1) in our near-shore study area. Residence times for dissolved Mn were estimated at 1.2 y for surface waters and 17 y at depth. The implications of Mn transport with CaCO 3 in relation to open-ocean sediment excess Mn are discussed.
Garaffa, Giulio; Sansalone, Salvatore; Ralph, David J
2013-01-01
During the most recent years, a variety of new techniques of penile reconstruction have been described in the literature. This paper focuses on the most recent advances in male genital reconstruction after trauma, excision of benign and malignant disease, in gender reassignment surgery and aphallia with emphasis on surgical technique, cosmetic and functional outcome. PMID:22426595
Design and performance of the SLD Vertex Detector, a 120 Mpixel tracking system
Agnew, G.D.; Cotton, R.; Damerell, C.J.S.
1992-03-01
This paper describes the design, construction, and initial operation of the SLD Vertex Detector, the first device to employ charge coupled devices (CCDs) on a large scale in a high energy physics experiment. The Vertex Detector comprises 480 CCDs, with a total of 120 Mpixels. Each pixel functions as an independent particle detecting element, providing space point measurements of charged particle tracks with a typical precision of 5 {mu}m in each co-ordinate. The CCDs are arranged in four concentric cylinders just outside the beam pipe which surrounds the e{sup +}e{sup {minus}} collision point of the SLAC Linear Collider (SLC). The Vertex Detector is a powerful tool for distinguishing secondary vertex tracks, produced by decay in flight of heavy flavour hadrons or tau leptons, from tracks produced at the primary event vertex. Because the colliding beam environment imposes severe constraints on the design of such a detector, a six year R&D programme was needed to develop solutions to a number of problems. The requirements include a low-mass structure (to minimise multiple scattering) both for mechanical support and to provide signal paths for the CCDS; operation at low temperature with a high degree of mechanical stability; and relatively high speed CCD readout, signal processing, and data sparsification. The lessons learned through the long R&D period should be useful for the construction of large arrays of CCDs or smart pixel devices in the future, in a number of areas of science and technology.
Glickel, Steven Z; Gupta, Salil
2006-05-01
Volar ligament reconstruction is an effective technique for treating symptomatic laxity of the CMC joint of the thumb. The laxity may bea manifestation of generalized ligament laxity,post-traumatic, or metabolic (Ehler-Danlos). There construction reduces the shear forces on the joint that contribute to the development and persistence of inflammation. Although there have been only a few reports of the results of volar ligament reconstruction, the use of the procedure to treat Stage I and Stage II disease gives good to excellent results consistently. More advanced stages of disease are best treated by trapeziectomy, with or without ligament reconstruction.
Barnes, Christopher P.
2005-03-01
The D0 detector underwent a major upgrade to maximize its ability to fully exploit Run II at the Fermilab Tevatron, the world's highest energy collider. The upgrade included a completely new central tracking system with an outer scintillating fiber tracker and an inner silicon vertex detector all within a 2T superconducting solenoid. This thesis describes the development of high level trigger algorithms including vertexing, impact parameter significance and invariant mass, that utilize tracks from these detectors. One of the main physics goals of Run II is the observation of B_{s} oscillations. This measurement, which cannot be performed at the B factories, will significantly constrain the ''unitarity triangle'' associated with Cp violation and so probe the Standard Model of particle physics. Furthermore this is an interesting measurement as the study of mixing in meson systems has a long history for revealing new physics. The second part of this thesis presents a study of the hadronic decay B_{s} → D_{s}π. This important mode provides the best proper time resolution for B_{s} mixing and is reconstructed for the first time at D0. Projections on the sensitivity to B_{s} oscillations are then presented.
Craniofacial reconstruction evaluation by geodesic network.
Zhao, Junli; Liu, Cuiting; Wu, Zhongke; Duan, Fuqing; Wang, Kang; Jia, Taorui; Liu, Quansheng
2014-01-01
Craniofacial reconstruction is to estimate an individual's face model from its skull. It has a widespread application in forensic medicine, archeology, medical cosmetic surgery, and so forth. However, little attention is paid to the evaluation of craniofacial reconstruction. This paper proposes an objective method to evaluate globally and locally the reconstructed craniofacial faces based on the geodesic network. Firstly, the geodesic networks of the reconstructed craniofacial face and the original face are built, respectively, by geodesics and isogeodesics, whose intersections are network vertices. Then, the absolute value of the correlation coefficient of the features of all corresponding geodesic network vertices between two models is taken as the holistic similarity, where the weighted average of the shape index values in a neighborhood is defined as the feature of each network vertex. Moreover, the geodesic network vertices of each model are divided into six subareas, that is, forehead, eyes, nose, mouth, cheeks, and chin, and the local similarity is measured for each subarea. Experiments using 100 pairs of reconstructed craniofacial faces and their corresponding original faces show that the evaluation by our method is roughly consistent with the subjective evaluation derived from thirty-five persons in five groups.
... This increases the chance you may have a meniscus tear. ACL reconstruction may be used for these ... When other ligaments are also injured When your meniscus is torn Before surgery, talk to your health ...
Vertex cover problem studied by cavity method: Analytics and population dynamics
NASA Astrophysics Data System (ADS)
Zhou, Haijun
2003-03-01
We study the vertex cover problem on finite connectivity random graphs by zero-temperature cavity method. The minimum vertex cover corresponds to the ground state(s) of a proposed Ising spin model. When the connectivity c > e = 2.718282, there is no state for this system as the reweighting parameter y, which takes a similar role as the inverse temperature β in conventional statistical physics, approaches infinity; consequently the ground state energy is obtained at a finite value of y when the free energy function attains its maximum value. The minimum vertex cover size at given c is estimated using population dynamics and compared with known rigorous bounds and numerical results. The backbone size is also calculated.
The Vertex Version of Weighted Wiener Number for Bicyclic Molecular Structures
Gao, Wei; Wang, Weifan
2015-01-01
Graphs are used to model chemical compounds and drugs. In the graphs, each vertex represents an atom of molecule and edges between the corresponding vertices are used to represent covalent bounds between atoms. We call such a graph, which is derived from a chemical compound, a molecular graph. Evidence shows that the vertex-weighted Wiener number, which is defined over this molecular graph, is strongly correlated to both the melting point and boiling point of the compounds. In this paper, we report the extremal vertex-weighted Wiener number of bicyclic molecular graph in terms of molecular structural analysis and graph transformations. The promising prospects of the application for the chemical and pharmacy engineering are illustrated by theoretical results achieved in this paper. PMID:26640513
Modeling & Informatics at Vertex Pharmaceuticals Incorporated: our philosophy for sustained impact
NASA Astrophysics Data System (ADS)
McGaughey, Georgia; Patrick Walters, W.
2016-11-01
Molecular modelers and informaticians have the unique opportunity to integrate cross-functional data using a myriad of tools, methods and visuals to generate information. Using their drug discovery expertise, information is transformed to knowledge that impacts drug discovery. These insights are often times formulated locally and then applied more broadly, which influence the discovery of new medicines. This is particularly true in an organization where the members are exposed to projects throughout an organization, such as in the case of the global Modeling & Informatics group at Vertex Pharmaceuticals. From its inception, Vertex has been a leader in the development and use of computational methods for drug discovery. In this paper, we describe the Modeling & Informatics group at Vertex and the underlying philosophy, which has driven this team to sustain impact on the discovery of first-in-class transformative medicines.
Vertex evoked potentials in a rating-scale detection task: Relation to signal probability
NASA Technical Reports Server (NTRS)
Squires, K. C.; Squires, N. K.; Hillyard, S. A.
1974-01-01
Vertex evoked potentials were recorded from human subjects performing in an auditory detection task with rating scale responses. Three values of a priori probability of signal presentation were tested. The amplitudes of the N1 and P3 components of the vertex potential associated with correct detections of the signal were found to be systematically related to the strictness of the response criterion and independent of variations in a priori signal probability. No similar evoked potential components were found associated with signal absent judgements (misses and correct rejections) regardless of the confidence level of the judgement or signal probability. These results strongly support the contention that the form of the vertex evoked response is closely correlated with the subject's psychophysical decision regarding the presence or absence of a threshold level signal.
Application of laser differential confocal technique in back vertex power measurement for phoropters
NASA Astrophysics Data System (ADS)
Li, Fei; Li, Lin; Ding, Xiang; Liu, Wenli
2012-10-01
A phoropter is one of the most popular ophthalmic instruments used in optometry and the back vertex power (BVP) is one of the most important parameters to evaluate the refraction characteristics of a phoropter. In this paper, a new laser differential confocal vertex-power measurement method which takes advantage of outstanding focusing ability of laser differential confocal (LDC) system is proposed for measuring the BVP of phoropters. A vertex power measurement system is built up. Experimental results are presented and some influence factor is analyzed. It is demonstrated that the method based on LDC technique has higher measurement precision and stronger environmental anti-interference capability compared to existing methods. Theoretical analysis and experimental results indicate that the measurement error of the method is about 0.02m-1.
Building a non-perturbative quark-gluon vertex from a perturbative one
NASA Astrophysics Data System (ADS)
Bermudez, Rocio
2016-10-01
The quark-gluon vertex describes the electromagnetic and the strong interaction among these particles. The description of this interaction at high precision in both regimes, perturbative and non-perturbative, continues being a matter of interest in the context of QCD and Hadron Physics. There exist very helpful models in the literature that explain perturbative aspects of the theory but they fail describing non-perturbative phenomena, as confinement and dynamic chiral symmetry breaking. In this work we study the structure of the quark-gluon vertex in a non-perturbative regime examining QCD, checking results with QED, and working in the Schwinger-Dyson formalism.
NLO vertex for a forward jet plus a rapidity gap at high energies
Hentschinski, Martin; Madrigal Martínez, José Daniel; Murdaca, Beatrice; ...
2015-04-01
Here we present the calculation of the forward jet vertex associated to a rapidity gap (coupling of a hard pomeron to the jet) in the BFKL formalism at next-to-leading order (NLO). Real emission contributions are computed via Lipatov’s effective action. The NLO jet vertex turns out to be finite within collinear factorization and allows, together with the NLO non-forward gluon Green’s function, to perform NLO studies of jet production in diffractive events (e.g. Mueller-Tang dijets).
The monodromy matrix in the F-basis for arbitrary six-vertex models
NASA Astrophysics Data System (ADS)
Martins, M. J.; Zuparic, M.
2011-10-01
We present the expressions for the monodromy matrix elements of the six-vertex model in the F-basis for arbitrary Boltzmann weights. The results rely solely on the property of unitarity and Yang-Baxter relations, avoiding any specific parameterization of the weights. This allows us to write complete algebraic expressions for the inner products and the underlying domain wall partition functions in the case of arbitrary rapidities. We then apply our results for the trigonometric six-vertex model in the presence of inhomogeneous electric fields and obtain a determinant formula for the respective on-shell scalar products.
NLO vertex for a forward jet plus a rapidity gap at high energies
Hentschinski, Martin; Madrigal Martínez, José Daniel; Murdaca, Beatrice; Vera, Agustín Sabio
2015-04-10
We present the calculation of the forward jet vertex associated to a rapidity gap (coupling of a hard pomeron to the jet) in the BFKL formalism at next-to-leading order (NLO). Real emission contributions are computed via Lipatov’s effective action. The NLO jet vertex turns out to be finite within collinear factorization and allows, together with the NLO non-forward gluon Green’s function, to perform NLO studies of jet production in diffractive events (e.g. Mueller-Tang dijets)
{kappa}K*{sup 0}{gamma}-vertex in light cone QCD sum rules
Gokalp, A.; Yilmaz, O.; Sarac, Y.
2008-06-01
We investigate the {kappa}K*{sup 0}{gamma}-vertex in the framework of light cone QCD sum rules. We estimate the coupling constant g{sub {kappa}}{sub K*{sup 0}}{sub {gamma}}, and compare our result with that used in the nonlinear chiral Lagrangian approach using the vector-meson dominance model in the SU(3) limit.
Conserved currents in the six-vertex and trigonometric solid-on-solid models
NASA Astrophysics Data System (ADS)
Ikhlef, Yacine; Weston, Robert
2017-04-01
We construct quasi-local conserved currents in the six-vertex model with anisotropy parameter η by making use of the quantum-group approach of Bernard and Felder. From these currents, we construct parafermionic operators with spin 1+\\text{i}η /π that obey a discrete-integral condition around lattice plaquettes embedded into the complex plane. These operators are identified with primary fields in a c = 1 compactified free Boson conformal field theory. We then consider a vertex-face correspondence that takes the six-vertex model to a trigonometric SOS model, and construct SOS operators that are the image of the six-vertex currents under this correspondence. We define corresponding SOS parafermionic operators with spins s = 1 and s=1+2\\text{i}η /π that obey discrete integral conditions around SOS plaquettes embedded into the complex plane. We consider in detail the cyclic-SOS case corresponding to the choice η =\\text{i}π ≤ft( p-{{p}\\prime}\\right)/p , with {{p}\\prime} coprime. We identify our SOS parafermionic operators in terms of the screening operators and primary fields of the associated c=1-6≤ft( p-{{p}\\prime}\\right){{}2}/p{{p}\\prime} conformal field theory.
Silicon drift devices for track and vertex detection at the SSC
Chen, W.; Kraner, H.; Li, Z.; Ng, C.; Radeka, V.; Rehak, P.; Rescia, S. ); Clark, J.; Henderson, S.; Hsu, L.; Oliver, J.; Wilson, R. ); Clemen, M.; Humanic, T.; Kraus, D.; Vilkelis, G.; Yu, B. ); McDonald, K.; Lu, C.; Wall, M. ); Vacchi, A. ); Bert
1990-01-01
We report on the recent progress in the study of Semiconductor Drift (Memory) Detectors intended for an inner tracking and vertexing system for the SSC. The systematic studies and the calibration of the existing detectors and the simulated performance in the actual SSC environment are highlighted. 5 refs., 22 figs., 1 tab.
Selective attention and the auditory vertex potential. 1: Effects of stimulus delivery rate
NASA Technical Reports Server (NTRS)
Schwent, V. L.; Hillyard, S. A.; Galambos, R.
1975-01-01
Enhancement of the auditory vertex potentials with selective attention to dichotically presented tone pips was found to be critically sensitive to the range of inter-stimulus intervals in use. Only at the shortest intervals was a clear-cut enhancement of the latency component to stimuli observed for the attended ear.
Human Performance on Hard Non-Euclidean Graph Problems: Vertex Cover
ERIC Educational Resources Information Center
Carruthers, Sarah; Masson, Michael E. J.; Stege, Ulrike
2012-01-01
Recent studies on a computationally hard visual optimization problem, the Traveling Salesperson Problem (TSP), indicate that humans are capable of finding close to optimal solutions in near-linear time. The current study is a preliminary step in investigating human performance on another hard problem, the Minimum Vertex Cover Problem, in which…
Operation of the CDF Silicon Vertex Detector with colliding beams at Fermilab
Bedeschi, F.; Bolognesi, V.; Dell'Agnello, S.; Galeotti, S.; Grieco, G.; Mariotti, M.; Menzione, A.; Punzi, G.; Raffaelli, F.; Ristori, L.; Tartarelli, F.; Turini, N.; Wenzel, H.; Zetti, F. ); Bailey, M.W.; Garfinkel, A.F.; Kruse, M.C.; Shaw, N.M. ); Carithers, W.C.; Ely, R.; Haber, C.; Holland, S.; Kleinfelder, S.; Merrick, T.; Schneide
1992-10-01
In this paper we briefly describe the main features of the CDF Silicon Vertex Detector (SVX) and discuss its performance during actual colliding beam operation at the Fermilab Tevatron. Details on S/N ratio, alignment, resolution and efficiency are given.
ERIC Educational Resources Information Center
Helisek, Harriet; Pratt, Donald
1994-01-01
Presents a project in which students monitor their use of trash, input and analyze information via a database and computerized graphs, and "reconstruct" extinct or endangered animals from recyclable materials. The activity was done with second-grade students over a period of three to four weeks. (PR)
ACL reconstruction - discharge
Anterior cruciate ligament reconstruction - discharge; ACL reconstruction - discharge ... had surgery to reconstruct your anterior cruciate ligament (ACL). The surgeon drilled holes in the bones of ...
Event Reconstruction Techniques in NOvA
NASA Astrophysics Data System (ADS)
Baird, M.; Bian, J.; Messier, M.; Niner, E.; Rocco, D.; Sachdev, K.
2015-12-01
The NOvA experiment is a long-baseline neutrino oscillation experiment utilizing the NuMI beam generated at Fermilab. The experiment will measure the oscillations within a muon neutrino beam in a 300 ton Near Detector located underground at Fermilab and a functionally-identical 14 kiloton Far Detector placed 810 km away. The detectors are liquid scintillator tracking calorimeters with a fine-grained cellular structure that provides a wealth of information for separating the different particle track and shower topologies. Each detector has its own challenges with the Near Detector seeing multiple overlapping neutrino interactions in each event and the Far Detector having a large background of cosmic rays due to being located on the surface. A series of pattern recognition techniques have been developed to go from event records, to spatially and temporally separating individual interactions, to vertexing and tracking, and particle identification. This combination of methods to achieve the full event reconstruction will be discussed.
A new Q-matrix in the eight-vertex model
NASA Astrophysics Data System (ADS)
Fabricius, Klaus
2007-04-01
We construct a Q-matrix for the eight-vertex model at roots of unity for crossing parameter η = 2mK/L with odd L, a case for which the existing constructions do not work. The new Q-matrix {\\skew3\\hat{Q}} depends on the spectral parameter v and also on a free parameter t. For t=0, {\\skew3\\hat{Q}} has the standard properties. For t ≠ 0, however, it does not commute with the operator S nor with itself for different values of the spectral parameter. We show that the six-vertex limit of {\\skew3\\hat{Q}}(v,t=iK^{\\prime}/2) exists.
Computational analysis of three-dimensional epithelial morphogenesis using vertex models
Du, XinXin; Osterfield, Miriam; Shvartsman, Stanislav Y.
2014-01-01
The folding of epithelial sheets, accompanied by cell shape changes and rearrangements, gives rise to three-dimensional structures during development. Recently, some aspects of epithelial morphogenesis have been modeled using vertex models, in which each cell is approximated by a polygon; however, these models have been largely confined to two dimensions. Here, we describe an adaptation of these models in which the classical two-dimensional vertex model is embedded in three dimensions. This modification allows for the construction of complex three-dimensional shapes from simple sheets of cells. We describe algorithmic, computational, and biophysical aspects of our model, with the view that it may be useful for formulating and testing hypotheses regarding the mechanical forces underlying a wide range of morphogenetic processes. PMID:25410646
An image matching method based on closed edges incorporated with vertex angles
NASA Astrophysics Data System (ADS)
Zhang, Baoming; Chen, Xiaowei; Lu, Jun; Gong, Zhihui; Guo, Haitao
2015-10-01
An image matching method based on closed edges incorporated with vertex angles is proposed in this paper. Based on edge detection results by Edison operator, invariant moments of closed edges and angles between the two branches for edge vertexes are used as matching entities to determine conjugate features candidates. The transformation relationship between images is approximated by similarity transformation model, and a set of transformation parameters can be determined by each pair of conjugate features after combining conjugate feature candidates in pair-wise. Furthermore, considering that the difference among transformation parameters which calculated by real conjugate features are minor, K-d tree method and K-means Spatial clustering method are used in succession to eliminate pairs which contain mismatching features. Therefore, conjugate features can be obtained from the similarity transformation parameters. Experimental results turn out that this method shows a stable performance and presents a satisfactory matching result.
Covariant and self-consistent vertex corrections for pions and isobars in nuclear matter
Korpa, C. L.; Lutz, M. F. M.; Riek, F.
2009-08-15
We evaluate the pion and isobar propagators in cold nuclear matter self-consistently applying a covariant form of the isobar-hole model. Migdal's vertex correction effects are considered systematically in the absence of phenomenological soft form factors. Saturated nuclear matter is modeled by scalar and vector mean fields for the nucleon. It is shown that the short-range dressing of the {pi}N{delta} vertex has a significant effect on the pion and isobar properties. Using realistic parameters sets we predict a downward shift of about 50 MeV for the {delta} resonance at nuclear saturation density. The pionic soft modes are much less pronounced than in previous studies.
A FASTBUS flash ADC system for the Mark II vertex chamber
Barker, L.
1988-10-01
This is a description of a flash ADC system built for the Mark II experiment at the Stanford Linear Accelerator Center (SLAC). This system was designed for use in the experiment's vertex chamber where signals could occur over a relatively long time, approximately 10 microseconds. This long time, coupled with fast cable amplifiers, necessitated an alternate design approach than was used with a dE/dX FASTBUS flash ADC design. 1 ref., 6 figs.
1985-10-14
Geometriae Dedicata 1975, 3, 469. *(6) Lipscomb, W. N. Science 1966, 153, 373. (7) King, R. B. J. Am. Chem. Soc. 1969, 91, 7211. * (8) Hoard, J. L...polyhedra given in Table 1 of Federico, P.J. Geometriae Dedicata 1975, 3, 469. The vertex index v7 v6v5 v4 v3 and the symmetry point group are given in
Error estimates for cell-vertex solutions of the compressible Euler equations
NASA Technical Reports Server (NTRS)
Roe, P. L.
1987-01-01
The cell-vertex schemes due to Ni and Jameson, et al. have been subjected to a theoretical analysis of their truncation error. The analysis confirms the authors' claims for second-order accuracy on smooth grids, but shows that the same accuracy cannot be obtained on arbitrary grids. It is shown that the schemes have a unique generalization to axisymmetric flow that preserves the second-order accuracy.
Influence of the nonperturbative quark-gluon vertex on the meson and baryon spectrum
Williams, Richard; Sanchis-Alepuz, Hèlios
2016-01-22
We present a calculation of the Hadron spectrum in the Dyson-Schwinger/Bethe-Salpeter approach to continuum QCD. A sophisticated truncation featuring all covariant structures of the quark-gluon vertex, with its inherent flavour dependence, is employed in a framework that preserves the dynamics of chiral symmetry breaking. The study is suggestive as to the relevance of additional resonant and non-resonant two- and three-body contributions.
Scalar vertex operator for bound-state QED in the Coulomb gauge
Holmberg, Johan
2011-12-15
Adkins's result [Phys. Rev. D 34, 2489 (1986)] for the time component of the renormalized vertex operator in Coulomb-gauge QED is separated according to its tensor structure and some of the Feynman parameter integrals are carried out analytically, yielding a form suited for numerical bound-state QED calculations. This modified form is applied to the evaluation of the self-energy shift to the binding energy in hydrogenic ions of high nuclear charge.
Diffusion archeology for diffusion progression history reconstruction.
Sefer, Emre; Kingsford, Carl
2016-11-01
Diffusion through graphs can be used to model many real-world processes, such as the spread of diseases, social network memes, computer viruses, or water contaminants. Often, a real-world diffusion cannot be directly observed while it is occurring - perhaps it is not noticed until some time has passed, continuous monitoring is too costly, or privacy concerns limit data access. This leads to the need to reconstruct how the present state of the diffusion came to be from partial diffusion data. Here, we tackle the problem of reconstructing a diffusion history from one or more snapshots of the diffusion state. This ability can be invaluable to learn when certain computer nodes are infected or which people are the initial disease spreaders to control future diffusions. We formulate this problem over discrete-time SEIRS-type diffusion models in terms of maximum likelihood. We design methods that are based on submodularity and a novel prize-collecting dominating-set vertex cover (PCDSVC) relaxation that can identify likely diffusion steps with some provable performance guarantees. Our methods are the first to be able to reconstruct complete diffusion histories accurately in real and simulated situations. As a special case, they can also identify the initial spreaders better than the existing methods for that problem. Our results for both meme and contaminant diffusion show that the partial diffusion data problem can be overcome with proper modeling and methods, and that hidden temporal characteristics of diffusion can be predicted from limited data.
A vertex specific dorsal selector Dve represses the ventral appendage identity in Drosophila head.
Kiritooshi, Naruto; Yorimitsu, Takeshi; Shirai, Tetsuya; Puli, Oorvashi Roy; Singh, Amit; Nakagoshi, Hideki
2014-08-01
Developmental fields are subdivided into lineage-restricted cell populations, known as compartments. In the eye imaginal disc of Drosophila, dorso-ventral (DV) lineage restriction is the primary event, whereas antero-posterior compartment boundary is the first lineage restriction in other imaginal discs. The Iroquois complex (Iro-C) genes function as dorsal selectors and repress the default, ventral, identity in the eye-head primordium. In Iro-C mutant clones, change of the dorsal identity to default ventral fate leads to generation of ectopic DV boundary, which results in dorsal eye enlargement, and duplication of ventral appendages like antenna and maxillary palp. Similar phenotypes were observed in heads with defective proventriculus (dve) mutant clones. Here, we show that the homeobox gene dve is a downstream effector of Iro-C in the dorsal head capsule (vertex) specification and represses the ventral (antennal) identity. Two homeodomain proteins Distal-less (Dll) and Homothorax (Hth) are known to be determinants of the antennal identity. Ectopic antenna formation in heads with dve mutant clones was associated with ectopic Dll expression and endogenous Hth expression in the vertex region. Interestingly, dve Dll double mutant clones could also induce ectopic antennae lacking the distal structures, suggesting that the Dve activity is crucial for repressing inappropriate antenna-forming potential in the vertex region. Our results clearly indicate that not only the activation of effector genes to execute developmental program but also the repression of inappropriate program is crucial for establishment of the organ identity.
Vertex Algebras W(p)Am and W(p)Dm and Constant Term Identities
NASA Astrophysics Data System (ADS)
Adamović, Dražen; Lin, Xianzu; Milas, Antun
2015-03-01
We consider AD-type orbifolds of the triplet vertex algebras W(p) extending the well-known c=1 orbifolds of lattice vertex algebras. We study the structure of Zhu's algebras A(W(p)^{A_m}) and A(W(p)^{D_m}), where A_m and D_m are cyclic and dihedral groups, respectively. A combinatorial algorithm for classification of irreducible W(p)^Γ-modules is developed, which relies on a family of constant term identities and properties of certain polynomials based on constant terms. All these properties can be checked for small values of m and p with a computer software. As a result, we argue that if certain constant term properties hold, the irreducible modules constructed in [Commun. Contemp. Math. 15 (2013), 1350028, 30 pages; Internat. J. Math. 25 (2014), 1450001, 34 pages] provide a complete list of irreducible W(p)^{A_m} and W(p)^{D_m}-modules. This paper is a continuation of our previous work on the ADE subalgebras of the triplet vertex algebra W(p).
Improvements to ATLAS track reconstruction for Run II
NASA Astrophysics Data System (ADS)
Cairo, Valentina Maria Martina
2016-07-01
Run II of the LHC will provide new challenges to track and vertex reconstruction with higher energies, denser jets and higher rates. A major change to the Inner Detector layout during the shutdown period has been the installation of the Insertable B-Layer, a fourth pixel layer located at a radius of 33 mm. This contribution discusses improvements to track reconstruction developed during the two year shutdown of the LHC. These include novel techniques developed to improve the performance in the dense cores of jets, optimisation for the expected conditions, and a big software campaign which lead to more than a factor of three decrease in the CPU time needed to process each recorded event.
Radio-interferometric Neutrino Reconstruction for the Askaryan Radio Array
NASA Astrophysics Data System (ADS)
Lu, Ming-Yuan
2017-03-01
The Askaryan Radio Array (ARA) is a neutrino telescope array under phased deployment near the South Pole. The array aims to discover and determine the ultra-high energy neutrino flux via detection of the Askaryan signal from neutrino-induced showers. This novel detection channel makes ARA the most cost-effective neutrino observatory in probing the neutrino flux from 1017eV - 1019eV. This contribution will discuss an interferometric vertex reconstruction technique developed for ARA, taking into account the curved paths traveled by EM radiation in inhomogeneous ice. Preliminary results on the directional reconstruction of an in situ calibration pulser as well as simulated neutrino vertices will be presented.
LOGISTIC NETWORK REGRESSION FOR SCALABLE ANALYSIS OF NETWORKS WITH JOINT EDGE/VERTEX DYNAMICS.
Almquist, Zack W; Butts, Carter T
2014-08-01
Change in group size and composition has long been an important area of research in the social sciences. Similarly, interest in interaction dynamics has a long history in sociology and social psychology. However, the effects of endogenous group change on interaction dynamics are a surprisingly understudied area. One way to explore these relationships is through social network models. Network dynamics may be viewed as a process of change in the edge structure of a network, in the vertex set on which edges are defined, or in both simultaneously. Although early studies of such processes were primarily descriptive, recent work on this topic has increasingly turned to formal statistical models. Although showing great promise, many of these modern dynamic models are computationally intensive and scale very poorly in the size of the network under study and/or the number of time points considered. Likewise, currently used models focus on edge dynamics, with little support for endogenously changing vertex sets. Here, the authors show how an existing approach based on logistic network regression can be extended to serve as a highly scalable framework for modeling large networks with dynamic vertex sets. The authors place this approach within a general dynamic exponential family (exponential-family random graph modeling) context, clarifying the assumptions underlying the framework (and providing a clear path for extensions), and they show how model assessment methods for cross-sectional networks can be extended to the dynamic case. Finally, the authors illustrate this approach on a classic data set involving interactions among windsurfers on a California beach.
Clustering analysis of the ground-state structure of the vertex-cover problem
NASA Astrophysics Data System (ADS)
Barthel, Wolfgang; Hartmann, Alexander K.
2004-12-01
Vertex cover is one of the classical NP-complete problems in theoretical computer science. A vertex cover of a graph is a subset of vertices such that for each edge at least one of the two endpoints is contained in the subset. When studied on Erdös-Rényi random graphs (with connectivity c ) one observes a threshold behavior: In the thermodynamic limit the size of the minimal vertex cover is independent of the specific graph. Recent analytical studies show that on the phase boundary, for small connectivities c
Design and construction of a Vertex Chamber and measurement of the average B-Hadron lifetime
Nelson, H.N.
1987-10-01
Four parameters describe the mixing of the three quark generations in the Standard Model of the weak charged current interaction. These four parameters are experimental inputs to the model. A measurement of the mean lifetime of hadrons containing b-quarks, or B-Hadrons, constrains the magnitudes of two of these parameters. Measurement of the B-Hadron lifetime requires a device that can measure the locations of the stable particles that result from B-Hadron decay. This device must function reliably in an inaccessible location, and survive high radiation levels. We describe the design and construction of such a device, a gaseous drift chamber. Tubes of 6.9 mm diameter, having aluminized mylar walls of 100 ..mu..m thickness are utilized in this Vertex Chamber. It achieves a spatial resolution of 45 ..mu..m, and a resolution in extrapolation to the B-Hadron decay location of 87 ..mu..m. Its inner layer is 4.6 cm from e/sup +/e/sup -/ colliding beams. The Vertex Chamber is situated within the MAC detector at PEP. We have analyzed botht he 94 pb/sup -1/ of integrated luminosity accumulated at ..sqrt..s = 29 GeV with the Vertex Chamber in place as well as the 210 pb/sup -1/ accumulated previously. We require a lepton with large momentum transverse to the event thrust axis to obtain a sample of events enriched in B-Hadron decays. The distribution of signed impact parameters of all tracks in these events is used to measure the B-Hadron flight distance, and hence lifetime. 106 refs., 79 figs., 20 tabs.
LOGISTIC NETWORK REGRESSION FOR SCALABLE ANALYSIS OF NETWORKS WITH JOINT EDGE/VERTEX DYNAMICS
Almquist, Zack W.; Butts, Carter T.
2015-01-01
Change in group size and composition has long been an important area of research in the social sciences. Similarly, interest in interaction dynamics has a long history in sociology and social psychology. However, the effects of endogenous group change on interaction dynamics are a surprisingly understudied area. One way to explore these relationships is through social network models. Network dynamics may be viewed as a process of change in the edge structure of a network, in the vertex set on which edges are defined, or in both simultaneously. Although early studies of such processes were primarily descriptive, recent work on this topic has increasingly turned to formal statistical models. Although showing great promise, many of these modern dynamic models are computationally intensive and scale very poorly in the size of the network under study and/or the number of time points considered. Likewise, currently used models focus on edge dynamics, with little support for endogenously changing vertex sets. Here, the authors show how an existing approach based on logistic network regression can be extended to serve as a highly scalable framework for modeling large networks with dynamic vertex sets. The authors place this approach within a general dynamic exponential family (exponential-family random graph modeling) context, clarifying the assumptions underlying the framework (and providing a clear path for extensions), and they show how model assessment methods for cross-sectional networks can be extended to the dynamic case. Finally, the authors illustrate this approach on a classic data set involving interactions among windsurfers on a California beach. PMID:26120218
Pre-stimulus alpha power affects vertex N2-P2 potentials evoked by noxious stimuli.
Babiloni, Claudio; Del Percio, Claudio; Brancucci, Alfredo; Capotosto, Paolo; Le Pera, Domenica; Marzano, Nicola; Valeriani, Massimiliano; Romani, Gian Luca; Arendt-Nielsen, Lars; Rossini, Paolo Maria
2008-03-28
It is well known that scalp potentials evoked by nonpainful visual and auditory stimuli are enhanced in amplitude when preceded by pre-stimulus low-amplitude alpha rhythms. This study tested the hypothesis that the same holds for the amplitude of vertex N2-P2 potentials evoked by brief noxious laser stimuli, an issue of interest for clinical perspective. EEG data were recorded in 10 subjects from 30 electrodes during laser noxious stimulation. The artifact-free vertex N2-P2 complex was spatially enhanced by surface Laplacian transformation. Pre-stimulus alpha power was computed at three alpha sub-bands according to subject's individual alpha frequency peak (i.e. about 6-8Hz for alpha 1, 8-10Hz for alpha 2 and 10-12Hz for alpha 3 sub-band). Individual EEG single trials were divided in two sub-groups. The strong-alpha sub-group (high band power) included halfway of all EEG single trials, namely those having the highest pre-stimulus alpha power. Weak-alpha sub-group (low band power) included the remaining trials. Averaging procedure provided laser evoked potentials for both trial sub-groups. No significant effect was found for alpha 1 and alpha 2 sub-bands. Conversely, compared to strong-alpha 3 sub-group, weak-alpha 3 sub-group showed vertex N2-P2 potentials having significantly higher amplitude (p<0.05). These results extend to the later phases of pain processing systems the notion that generation mechanisms of pre-stimulus alpha rhythms and (laser) evoked potentials are intrinsically related and subjected to fluctuating "noise". That "noise" could explain the trial-by-trial variability of laser evoked potentials and perception.
{kappa}K{sup +{pi}-} vertex in light cone QCD sum rules
Baytemir, G.; Sarac, Y.; Yilmaz, O.
2010-05-01
In this work we study the {kappa}K{sup +{pi}-} vertex in the framework of light cone QCD sum rules. We predict the coupling constant g{sub {kappa}K}{sup +}{sub {pi}}{sup -} to be g{sub {kappa}K}{sup +}{sub {pi}}{sup -}=(6.0{+-}1.0) GeV and estimate the scalar f{sub 0}-{sigma} mixing angle from the experimental ratio g{sup 2}({kappa}{yields}K{pi})/g{sup 2}({sigma}{yields}{pi}{pi}).
TGV32: A 32-channel preamplifier chip for the multiplicity vertex detector at PHENIX
Britton, C.L. Jr.; Ericson, M.N.; Frank, S.S.
1997-12-31
The TGV32, a 32-channel preamplifier-multiplicity discriminator chip for the Multiplicity Vertex Detector (MVD) at PHENIX, is a unique silicon preamplifier in that it provides both an analog output for storage in an analog memory and a weighted summed-current output for conversion to a channel multiplicity count. The architecture and test results of the chip are presented. Details about the design of the preamplifier, discriminator, and programmable digital-analog converters (DACs) performance as well as the process variations are presented. The chip is fabricated in a 1.2-{micro}m, n-well, CMOS process.
The loop-cluster algorithm for the case of the 6 vertex model
NASA Astrophysics Data System (ADS)
Evertz, Hans Gerd; Marcu, Mihai
1993-03-01
We present the loop algorithm, a new type of cluster algorithm that we recently introduced for the F model. Using the framework of Kandel and Domany, we show how to generalize the algorithm to the arrow flip symmetric 6 vertex model. We propose the principle of least possible freezing as the guide to choosing the values of free parameters in the algorithm. Finally, we briefly discuss the application of our algorithm to simulations of quantum spin systems. In particular, all necessary information is provided for the simulation of spin {1}/{2} Heisenberg and ¢x¢x z models.
Dowell, L.J.
1998-10-01
This paper enumerates the configurations of a pair of vertices (one of which is a leaf) relative to the unique vertex one center and the leaf of greatest path length from this center in a spanning tree of a graph. From this enumeration, it demonstrates that the vertex one center is between the vertex and the leaf of greatest path length from the vertex for every such pair of vertices. Using this result this paper develops an algorithm for the optimal reconfiguration of a tree infrastructure required to recover from the failure of a network element.
Design of the cooling systems for the multiplicity and vertex detector
Bernardin, J.D.; Cunningham, R.
1997-11-01
The PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory is being constructed to investigate a phase of matter termed the quark-gluon plasma. The plasma will be produced through the collision of two heavy ions. The multiplicity and vertex detector (MVD) located in the center of PHENIX will characterize the events, determine the collision point, and act as a central trigger. This report presents the final mechanical designs of the cooling systems for the Multiplicity and Vertex Detector (MVD). In particular, the design procedure and layouts are discussed for two different air cooling systems for the multichip modules and MVD enclosure, and a liquid cooling system for the low dropout voltage regulators. First of all, experimental prototype cooling system test results used to drive the final mechanical designs are summarized and discussed. Next, the cooling system requirements and design calculation for the various subsystem components are presented along with detailed lists of supply vendors, components, and costs. Finally, safety measures incorporated in the final mechanical design and operation procedures for each of the subsystems are detailed.
Vertex-wise examination of depressive symptom dimensions and brain volumes in older adults.
McLaren, Molly E; Szymkowicz, Sarah M; O'Shea, Andrew; Woods, Adam J; Anton, Stephen D; Dotson, Vonetta M
2017-02-28
Differences in brain volumes have commonly been reported in older adults with both subthreshold and major depression. Few studies have examined the association between specific symptom dimensions of depression and brain volumes. This study used vertex-wise analyses to examine the association between specific symptom dimensions of depression and brain volumes in older adults with subthreshold levels of depressive symptoms. Forty-three community-dwelling adults between the ages of 55 and 81 years underwent a structural Magnetic Resonance Imaging scan and completed the Center for Epidemiologic Studies Depression Scale (CES-D). Vertex-wise analyses were conducted using Freesurfer Imaging Suite to examine the relationship between CES-D subscale scores and gray matter volumes while controlling for sex, age, and education. We found distinct associations between depressed mood, somatic symptoms, and lack of positive affect subscales with regional volumes, including primarily positive relationships in temporal regions and a negative association with the lingual gyrus. The relationship between higher depressed mood subscale scores and larger volumes in the left inferior temporal lobe withstood Monte-Carlo correction for multiple comparisons. Results from this preliminary study highlight the importance of examining depression on a symptom dimension level and identify brain regions that may be important in larger studies of depression.
Deptuch, Grzegorz; Christian, David; Hoff, James; Lipton, Ronald; Shenai, Alpana; Trimpl, Marcel; Yarema, Raymond; Zimmerman, Tom; /Fermilab
2008-12-01
3D-Integrated Circuit technology enables higher densities of electronic circuitry per unit area without the use of nanoscale processes. It is advantageous for mixed mode design with precise analog circuitry because processes with conservative feature sizes typically present lower process dispersions and tolerate higher power supply voltages, resulting in larger separation of a signal from the noise floor. Heterogeneous wafers (different foundries or different process families) may be combined with some 3D integration methods, leading to the optimization of each tier in the 3D stack. Tracking and vertexing in future High-Energy Physics (HEP) experiments involves construction of detectors composed of up to a few billions of channels. Readout electronics must record the position and time of each measurement with the highest achievable precision. This paper reviews a prototype of the first 3D readout chip for HEP, designed for a vertex detector at the International Linear Collider. The prototype features 20 x 20 {micro}m{sup 2} pixels, laid out in an array of 64 x 64 elements and was fabricated in a 3-tier 0.18 {micro}m Fully Depleted SOI CMOS process at MIT-Lincoln Laboratory. The tests showed correct functional operation of the structure. The chip performs a zero-suppressed readout. Successive submissions are planned in a commercial 3D bulk 0.13 {micro}m CMOS process to overcome some of the disadvantages of an FDSOI process.
The micro-vertex-detector of the PANDA experiment at Darmstadt
NASA Astrophysics Data System (ADS)
Stockmanns, Tobias
2006-11-01
The "AntiProton ANnihilations at DArmstadt"—experiment, short PANDA, is one of the main experiments of the "Facility for Antiproton and Ion Research" (FAIR) which replaces and extends the existing GSI-facility at Darmstadt. The main physics goals at the beginning of the experiment in 2012 will be precision spectroscopy of charmonium states, an establishment of gluonic excitations, the search for modifications of meson properties in the nuclear medium and precision γ-ray spectroscopy of single and double hypernuclei. For many of these physics goals an identification of D-mesons via the detection of a secondary vertex with a decay length in the order of 100 μm is essential. Therefore, a special micro-vertex-detector (MVD) is foreseen which allows a precise tracking of all charged particles. Several different technology options from monolithic active pixels to hybrid pixel detectors are on the market. Unfortunately, none of these techniques fully meets the requirements of the PANDA experiment. Different technologies are compared with respect to the requirements of PANDA. In addition, a possible design of the MVD will be shown, which features a combination of hybrid pixel modules, whose layout might be adopted from ATLAS or other LHC experiments, for the inner layers and silicon strip detectors for the outer layers.
Symmetry classes of alternating sign matrices in a nineteen-vertex model
NASA Astrophysics Data System (ADS)
Hagendorf, Christian; Morin-Duchesne, Alexi
2016-05-01
The nineteen-vertex model of Fateev and Zamolodchikov on a periodic lattice with an anti-diagonal twist is investigated. Its inhomogeneous transfer matrix is shown to have a simple eigenvalue, with the corresponding eigenstate displaying intriguing combinatorial features. Similar results were previously found for the same model with a diagonal twist. The eigenstate for the anti-diagonal twist is explicitly constructed using the quantum separation of variables technique. A number of sum rules and special components are computed and expressed in terms of Kuperberg’s determinants for partition functions of the inhomogeneous six-vertex model. The computations of some components of the special eigenstate for the diagonal twist are also presented. In the homogeneous limit, the special eigenstates become eigenvectors of the Hamiltonians of the integrable spin-one XXZ chain with twisted boundary conditions. Their sum rules and special components for both twists are expressed in terms of generating functions arising in the weighted enumeration of various symmetry classes of alternating sign matrices (ASMs). These include half-turn symmetric ASMs, quarter-turn symmetric ASMs, vertically symmetric ASMs, vertically and horizontally perverse ASMs and double U-turn ASMs. As side results, new determinant and pfaffian formulas for the weighted enumeration of various symmetry classes of alternating sign matrices are obtained.
NASA Astrophysics Data System (ADS)
OświÈ©cimka, Paweł; Livi, Lorenzo; DroŻdŻ, Stanisław
2016-10-01
We investigate the scaling of the cross-correlations calculated for two-variable time series containing vertex properties in the context of complex networks. Time series of such observables are obtained by means of stationary, unbiased random walks. We consider three vertex properties that provide, respectively, short-, medium-, and long-range information regarding the topological role of vertices in a given network. In order to reveal the relation between these quantities, we applied the multifractal cross-correlation analysis technique, which provides information about the nonlinear effects in coupling of time series. We show that the considered network models are characterized by unique multifractal properties of the cross-correlation. In particular, it is possible to distinguish between Erdös-Rényi, Barabási-Albert, and Watts-Strogatz networks on the basis of fractal cross-correlation. Moreover, the analysis of protein contact networks reveals characteristics shared with both scale-free and small-world models.
Overview of the Micro Vertex Detector for the P bar ANDA experiment
NASA Astrophysics Data System (ADS)
Calvo, Daniela
2017-02-01
The P bar ANDA experiment is devoted to study interactions between cooled antiproton beams and a fixed target (the interaction rate is of about 107 events/s), hydrogen or heavier nuclei. The innermost tracker of P bar ANDA is the Micro Vertex Detector (MVD), specially designed to ensure the secondary vertex resolution for the discrimination of short-lived charmonium states. Hybrid epitaxial silicon pixels and double-sided silicon microstrips will equip four barrels, arranged around the interaction point, and six forward disks. The experiment features a triggerless architecture with a master clock of 160 MHz, therefore the MVD has to run with a continuous data transmission where the hits need precise timestamps. The energy loss of the particles in the sensor will be measured as well. The challenging request of a triggerless readout suggested to develop custom readout chips for both pixel (ToPix) and microstrip (PASTA) devices. To validate components and the triggerless readout architecture, prototypes have been built and tested. After an overview of the MVD, the technological aspects and performances of some prototypes will be reported.
Plethysms, replicated Schur functions and series, with applications to vertex operators
NASA Astrophysics Data System (ADS)
Fauser, Bertfried; Jarvis, Peter D.; King, Ronald C.
2010-10-01
Specializations of Schur functions are exploited to define and evaluate the Schur functions sλ[αX] and plethysms sλ[αsν(X))] for any α—integer, real or complex. Plethysms are then used to define pairs of mutually inverse infinite series of Schur functions, Mπ and Lπ, specified by arbitrary partitions π. These are used in turn to define and provide generating functions for formal characters, s(π)λ, of certain groups Hπ, thereby extending known results for orthogonal and symplectic group characters. Each of these formal characters is then given a vertex operator realization, first in terms of the series M = M(0) and various L⊥σ dual to Lσ, and then more explicitly in the exponential form. Finally the replicated form of such vertex operators are written down. The characters of the orthogonal and symplectic groups have been found by Schur [34] and Weyl [35] respectively. The method used is transcendental, and depends on integration over the group manifold. These characters, however, may be obtained by purely algebraic methods,.... This algebraic method would seem to offer a better prospect of successful application to other restricted groups than the method of group integration. Littlewood D E 1944 Phil. Trans. R. Soc. London, Ser. A 239 (809) 392
NASA Astrophysics Data System (ADS)
Di Pietro, V.; Brinkmann, K.-Th.; Riccardi, A.; Ritman, J.; Rivetti, A.; Rolo, M. D.; Stockmanns, T.; Zambanini, A.
2016-03-01
The bar PANDA (Antiproton Annihilation at Darmstadt) experiment foresees many detectors for tracking, particle identification and calorimetry. Among them, the innermost is the MVD (Micro Vertex Detector) responsible for a precise tracking and the reconstruction of secondary vertices. This detector will be built from both hybrid pixel (two inner barrels and six forward disks) and double-sided micro strip (two outer barrels and outer rim of the last two disks) silicon sensors. A time-based approach has been chosen for the readout ASIC of the strip sensors. The PASTA (bar PANDA Strip ASIC) chip aims at high resolution time-stamping and charge information through the Time over Threshold (ToT) technique. It benefits from a Time to Digital Converter (TDC) allowing a time bin width down to 50 ps. The analog front-end was designed to serve both n-type and p-type strips and the performed simulations show remarkable performances in terms of linearity and electronic noise. The TDC consists of an analog interpolator, a digital local controller, and a digital global controller as the common back-end for all of the 64 channels.
Chang, Weng-Long; Ren, Ting-Ting; Feng, Mang
2015-01-01
In this paper, it is shown that the proposed quantum algorithm for implementing Boolean circuits generated from the DNA-based algorithm solving the vertex-cover problem of any graph G with m edges and n vertices is the optimal quantum algorithm. Next, it is also demonstrated that mathematical solutions of the same biomolecular solutions are represented in terms of a unit vector in the finite-dimensional Hilbert space. Furthermore, for testing our theory, a nuclear magnetic resonance (NMR) experiment of three quantum bits to solve the simplest vertex-cover problem is completed.
Bachacou, Henri
2004-12-01
A measurement of the t$\\bar{t}$ pair production cross section is presented using 162 pb^{ -1 }of data collected by the CDF experiment during Run II at the Tevatron. t$\\bar{t}$} events in the lepton+jets channel are isolated by identifying electrons and muons, reconstructing jets and transverse missing energy, and identifying b jets with a secondary vertex tagging algorithm. The efficiency of the algorithm is measured in a control sample using a novel technique that is less dependent on the simulation. For a top quark mass of 175 GeV/c^{2 }, a cross section of σ_{t$\\bar{t}$} = 5.6$+1.2\\atop{-1.1}$(stat.)$+0.9\\atop{-0.6}$(syst.)pb is measured.
Neuromagnetic source reconstruction
Lewis, P.S.; Mosher, J.C.; Leahy, R.M.
1994-12-31
In neuromagnetic source reconstruction, a functional map of neural activity is constructed from noninvasive magnetoencephalographic (MEG) measurements. The overall reconstruction problem is under-determined, so some form of source modeling must be applied. We review the two main classes of reconstruction techniques-parametric current dipole models and nonparametric distributed source reconstructions. Current dipole reconstructions use a physically plausible source model, but are limited to cases in which the neural currents are expected to be highly sparse and localized. Distributed source reconstructions can be applied to a wider variety of cases, but must incorporate an implicit source, model in order to arrive at a single reconstruction. We examine distributed source reconstruction in a Bayesian framework to highlight the implicit nonphysical Gaussian assumptions of minimum norm based reconstruction algorithms. We conclude with a brief discussion of alternative non-Gaussian approachs.
Cone-beam image reconstruction using spherical harmonics.
Taguchi, K; Zeng, G L; Gullberg, G T
2001-06-01
Image reconstruction from cone-beam projections is required for both x-ray computed tomography (CT) and single photon emission computed tomography (SPECT). Grangeat's algorithm accurately performs cone-beam reconstruction provided that Tuy's data sufficiency condition is satisfied and projections are complete. The algorithm consists of three stages: (a) Forming weighted plane integrals by calculating the line integrals on the cone-beam detector, and obtaining the first derivative of the plane integrals (3D Radon transform) by taking the derivative of the weighted plane integrals. (b) Rebinning the data and calculating the second derivative with respect to the normal to the plane. (c) Reconstructing the image using the 3D Radon backprojection. A new method for implementing the first stage of Grangeat's algorithm was developed using spherical harmonics. The method assumes that the detector is large enough to image the whole object without truncation. Computer simulations show that if the trajectory of the cone vertex satisfies Tuy's data sufficiency condition, the proposed algorithm provides an exact reconstruction.
Event Reconstruction for Many-core Architectures using Java
Graf, Norman A.; /SLAC
2012-04-19
Although Moore's Law remains technically valid, the performance enhancements in computing which traditionally resulted from increased CPU speeds ended years ago. Chip manufacturers have chosen to increase the number of core CPUs per chip instead of increasing clock speed. Unfortunately, these extra CPUs do not automatically result in improvements in simulation or reconstruction times. To take advantage of this extra computing power requires changing how software is written. Event reconstruction is globally serial, in the sense that raw data has to be unpacked first, channels have to be clustered to produce hits before those hits are identified as belonging to a track or shower, tracks have to be found and fit before they are vertexed, etc. However, many of the individual procedures along the reconstruction chain are intrinsically independent and are perfect candidates for optimization using multi-core architecture. Threading is perhaps the simplest approach to parallelizing a program and Java includes a powerful threading facility built into the language. We have developed a fast and flexible reconstruction package (org.lcsim) written in Java that has been used for numerous physics and detector optimization studies. In this paper we present the results of our studies on optimizing the performance of this toolkit using multiple threads on many-core architectures.
New limits on anomalous contributions to the W t b vertex
NASA Astrophysics Data System (ADS)
Birman, J. L.; Déliot, F.; Fiolhais, M. C. N.; Onofre, A.; Pease, C. M.
2016-06-01
The latest and most precise top quark measurements at the LHC and Tevatron are used to establish new limits on the W t b vertex. Recent results on the measurements of the W -boson helicity fractions and single top quark production cross section are combined in order to establish new limits at 95% CL (confidence level). The allowed regions for these limits are presented, for the first time, in three-dimensional graphics, for both real and imaginary components of the different anomalous couplings, providing a new perspective on the impact of the combination of different physics observables. These results are also combined with the prospected future measurement of the single top quark production cross section and W -boson helicity fractions at the LHC.
Software Development for the Commissioning of the Jefferson Lab Hall B Silicon Vertex Tracker
NASA Astrophysics Data System (ADS)
Ruger, Justin; Ziegler, Veronique; Gotra, Yuri; Gavalian, Gagik
2015-04-01
One of the new additions to Hall B at the Thomas Jefferson National Accelerator Facility is a Silicon Vertex Tracker system that includes 4 regions with 10, 14, 18, 24 sectors of double-sided modules. Recently, the SVT hardware group has completed construction and installation of regions one and two on a cosmic ray test stand. This test setup will be used to preform the first cosmic ray efficiency analysis of the SVT with the availability of 8 measurement layers. In order to study efficiency and module performance, a set of software packages had to be written to decode, analyze and provide feedback on the output from data acquisition. This talk will provide an overview of the software validation suite designed and developed for Hall B and a report on its current utilization for SVT cosmic data analysis.
NASA Astrophysics Data System (ADS)
Zhang, Cheng; Bansal, Bhupesh; Branicio, Paulo S.; Kalia, Rajiv K.; Nakano, Aiichiro; Sharma, Ashish; Vashishta, Priya
2006-09-01
State-of-the-art molecular dynamics (MD) simulations generate massive datasets involving billion-vertex chemical bond networks, which makes data mining based on graph algorithms such as K-ring analysis a challenge. This paper proposes an algorithm to improve the efficiency of ring analysis of large graphs, exploiting properties of K-rings and spatial correlations of vertices in the graph. The algorithm uses dual-tree expansion (DTE) and spatial hash-function tagging (SHAFT) to optimize computation and memory access. Numerical tests show nearly perfect linear scaling of the algorithm. Also a parallel implementation of the DTE + SHAFT algorithm achieves high scalability. The algorithm has been successfully employed to analyze large MD simulations involving up to 500 million atoms.
tbW vertex in the littlest Higgs model with T parity
Penunuri, F.; Larios, F.
2009-01-01
A study of the effective tbW vertex is done in the littlest Higgs model with T parity that includes the one-loop induced weak dipole coefficient f{sub 2R}. The top's width and the W-boson helicity in the t{yields}bW{sup +} decay as well as the t-channel and the s-channel modes of single top quark production at the LHC are then obtained for the tbW coupling. Our calculation is done in the Feynman-'t Hooft gauge, and we provide details of the analysis, like exact formulas (to all orders of the expansion variable v/f) of masses and mixing angles of all of the particles involved. Also, a complete and exact diagonalization (and normalization) of the scalar sector of the model is made.
Nuclear vertex constants and asymptotic normalization coefficients for the tritium nucleus
Babenko, V. A.; Petrov, N. M.
2009-12-15
The properties of the nuclear vertex constant for virtual triton decay to a deuteron and a neutron (T {sup {yields}} d + n) are investigated along with the properties of the asymptotic normalization coefficient defined for the triton wave function and related to this constant. These quantities are calculated numerically on the basis of an equation that relates the asymptotic normalization coefficient to the triton effective radius {rho}{sub T}, which was introduced in the present study. The values of G{sub T}{sup 2} = 1.244(68) fm and C{sub T}{sup 2} = 2.958(162) found from our calculations are in good agreement with experimental and theoretical estimates obtained for these quantities in other studies. Physical properties of the triton virtual state are also discussed.
The silicon Micro Vertex Detector of the P bar ANDA experiment
NASA Astrophysics Data System (ADS)
Calvo, D.; Panda Collaboration
2013-08-01
The P bar ANDA experiment will make use of cooled antiproton beams of unprecedented quality that will become available at the Facility for Antiproton and Ion Research in Darmstadt, featuring a 1.5-15 GeV/c momentum range. The physics program includes measurements of hyperons produced at low energies, spectroscopy of charmonium and open-charm mesons. To handle the forward peaked particle distribution due to the Lorentz boost, the apparatus is arranged in an asymmetric layout around the interaction point. In particular the Micro Vertex Detector based on silicon devices will have a rather unusual geometry. The MVD features fast data readout, since the experiment is triggerless, particle identification over the full range of energies, limited material budget and good spatial and time resolution. The status of the MVD design is shown and the present prototypes are described.
A high rate, low radiation length Micro-Vertex-Detector for the P¯ANDA experiment
NASA Astrophysics Data System (ADS)
Stockmanns, Tobias
2011-09-01
The Micro-Vertex-Detector (MVD) of the P¯ANDA experiment is the innermost tracking detector. Its most challenging task is the identification of D-meson pairs by their delayed decay point which is about 100- 500 μm from the production point. In addition to the necessary high spatial resolution, it needs a time resolution on the order of 10 ns, a moderate radiation hardness, an untriggered readout of hit data up to 500 MBit/s and a low radiation length. To meet these challenging requirements an intense R&D program is ongoing on all parts of the MVD. This article gives an overview of the ongoing technical developments with a focus on the pixel part of the project.
Front-end module readout and control electronics for the PHENIX Multiplicity Vertex Detector
Ericson, M.N.; Allen, M.D.; Boissevain, J.
1997-11-01
Front-end module (FEM) readout and control are implemented as modular, high-density, reprogrammable functions in the PHENIX Multiplicity Vertex Detector. FEM control is performed by the heap manager, an FPGA-based circuit in the FEM unit. Each FEM has 256 channels of front-end electronics, readout, and control, all located on an MCM. Data readout, formatting, and control are performed by the heap manager along with 4 interface units that reside outside the MVD detector cylinder. This paper discusses the application of a generic heap manager and the addition of 4 interface module types to meet the specific control and data readout needs of the MVD. Unit functioning, interfaces, timing, data format, and communication rates will be discussed in detail. In addition, subsystem issues regarding mode control, serial architecture and functions, error handling, and FPGA implementation and programming will be presented.
Exploitation of secondary vertex information at the CDF detector. Final report, 1991--1994
Amidei, D.
1995-11-01
In the proposal for this work, submitted in November 1990, the author described the application of silicon micro-vertex tracking to hadron collider physics, and outlined a plan of involvement in the first such application, at the CDF Detector, studying p{anti p} collisions at {radical}s = 1.8 TeV at the Fermilab Tevatron. The proposal included discussion on the use of silicon tracking in B physics measurements, and also some speculation on the ability of silicon tracking to aid in identification of the top quark. In the five years since this proposal, the author has played a significant role in the installation and commissioning of the first such silicon tracking device at a hadron collider, and the utilization of this device in the discovery of the top quark and the study of B production mechanisms. This paper is a summary of this work.
A bottom collider vertex detector design, Monte-Carlo simulation and analysis package
Lebrun, P.
1990-10-01
A detailed simulation of the BCD vertex detector is underway. Specifications and global design issues are briefly reviewed. The BCD design based on double sided strip detector is described in more detail. The GEANT3-based Monte-Carlo program and the analysis package used to estimate detector performance are discussed in detail. The current status of the expected resolution and signal to noise ratio for the golden'' CP violating mode B{sub d} {yields} {pi}{sup +}{pi}{sup {minus}} is presented. These calculations have been done at FNAL energy ({radical}s = 2.0 TeV). Emphasis is placed on design issues, analysis techniques and related software rather than physics potentials. 20 refs., 46 figs.
Bernardin, J.D.; Bosze, E.; Boissevain, J.; Simon-Gillo, J.
1997-07-01
This report summarizes an experimental investigation of vibrations within the multiplicity and vertex detector (MVD). In particular, the maximum displacements of several MVD components were determined from accelerometer measurements of vibrations induced by an electronics air-cooling system. For an MVD inlet air volumetric flow rate of 0.022 m{sup 3}/s, maximum displacements of several MVD components including a multi-chip module, the Rohacell inlet air plenum, and an aluminum structural cross support, were found to be on the order of 1.5 {mu}m. Consequently, it was concluded that air induced vibrations will not significantly interfere with the MVD`s long-term structural integrity or operating performance. 2 refs., 3 figs., 1 tab.
A bonding study toward the quality assurance of Belle-II silicon vertex detector modules
NASA Astrophysics Data System (ADS)
Kang, K. H.; Jeon, H. B.; Park, H.; Uozumi, S.; Adamczyk, K.; Aihara, H.; Angelini, C.; Aziz, T.; Babu, V.; Bacher, S.; Bahinipati, S.; Barberio, E.; Baroncelli, T.; Basith, A. K.; Batignani, G.; Bauer, A.; Behera, P. K.; Bergauer, T.; Bettarini, S.; Bhuyan, B.; Bilka, T.; Bosi, F.; Bosisio, L.; Bozek, A.; Buchsteiner, F.; Casarosa, G.; Ceccanti, M.; Červenkov, D.; Chendvankar, S. R.; Dash, N.; Divekar, S. T.; Doležal, Z.; Dutta, D.; Forti, F.; Friedl, M.; Hara, K.; Higuchi, T.; Horiguchi, T.; Irmler, C.; Ishikawa, A.; Joo, C. W.; Kandra, J.; Kato, E.; Kawasaki, T.; Kodyš, P.; Kohriki, T.; Koike, S.; Kolwalkar, M. M.; Kvasnička, P.; Lanceri, L.; Lettenbicher, J.; Mammini, P.; Mayekar, S. N.; Mohanty, G. B.; Mohanty, S.; Morii, T.; Nakamura, K. R.; Natkaniec, Z.; Negishi, K.; Nisar, N. K.; Onuki, Y.; Ostrowicz, W.; Paladino, A.; Paoloni, E.; Pilo, F.; Profeti, A.; Rao, K. K.; Rashevskaia, I.; Rizzo, G.; Rozanska, M.; Sandilya, S.; Sasaki, J.; Sato, N.; Schultschik, S.; Schwanda, C.; Seino, Y.; Shimizu, N.; Stypula, J.; Tanaka, S.; Tanida, K.; Taylor, G. N.; Thalmeier, R.; Thomas, R.; Tsuboyama, T.; Urquijo, P.; Vitale, L.; Volpi, M.; Watanuki, S.; Watson, I. J.; Webb, J.; Wiechczynski, J.; Williams, S.; Würkner, B.; Yamamoto, H.; Yin, H.; Yoshinobu, T.
2016-09-01
A silicon vertex detector (SVD) for the Belle-II experiment comprises four layers of double-sided silicon strip detectors (DSSDs), assembled in a ladder-like structure. Each ladder module of the outermost SVD layer has four rectangular and one trapezoidal DSSDs supported by two carbon-fiber ribs. In order to achieve a good signal-to-noise ratio and minimize material budget, a novel chip-on-sensor "Origami" method has been employed for the three rectangular sensors that are sandwiched between the backward rectangular and forward (slanted) trapezoidal sensors. This paper describes the bonding procedures developed for making electrical connections between sensors and signal fan-out flex circuits (i.e., pitch adapters), and between pitch adapters and readout chips as well as the results in terms of the achieved bonding quality and pull force.
NASA Technical Reports Server (NTRS)
Schwent, V. L.; Hillyard, S. A.; Galambos, R.
1975-01-01
A randomized sequence of tone bursts was delivered to subjects at short inter-stimulus intervals with the tones originating from one of three spatially and frequency specific channels. The subject's task was to count the tones in one of the three channels at a time, ignoring the other two, and press a button after each tenth tone. In different conditions, tones were given at high and low intensities and with or without a background white noise to mask the tones. The N sub 1 component of the auditory vertex potential was found to be larger in response to attended channel tones in relation to unattended tones. This selective enhancement of N sub 1 was minimal for loud tones presented without noise and increased markedly for the lower tone intensity and in noise added conditions.
A cell-vertex multigrid method for the Navier-Stokes equations
NASA Technical Reports Server (NTRS)
Radespiel, R.
1989-01-01
A cell-vertex scheme for the Navier-Stokes equations, which is based on central difference approximations and Runge-Kutta time stepping, is described. Using local time stepping, implicit residual smoothing, a multigrid method, and carefully controlled artificial dissipative terms, very good convergence rates are obtained for a wide range of two- and three-dimensional flows over airfoils and wings. The accuracy of the code is examined by grid refinement studies and comparison with experimental data. For an accurate prediction of turbulent flows with strong separations, a modified version of the nonequilibrium turbulence model of Johnson and King is introduced, which is well suited for an implementation into three-dimensional Navier-Stokes codes. It is shown that the solutions for three-dimensional flows with strong separations can be dramatically improved, when a nonequilibrium model of turbulence is used.
Evaporative CO2 cooling using microchannels etched in silicon for the future LHCb vertex detector
NASA Astrophysics Data System (ADS)
Nomerotski, A.; Buytart, J.; Collins, P.; Dumps, R.; Greening, E.; John, M.; Mapelli, A.; Leflat, A.; Li, Y.; Romagnoli, G.; Verlaat, B.
2013-04-01
The extreme radiation dose received by vertex detectors at the Large Hadron Collider dictates stringent requirements on their cooling systems. To be robust against radiation damage, sensors should be maintained below -20°C and at the same time, the considerable heat load generated in the readout chips and the sensors must be removed. Evaporative CO2 cooling using microchannels etched in a silicon plane in thermal contact with the readout chips is an attractive option. In this paper, we present the first results of microchannel prototypes with circulating, two-phase CO2 and compare them to simulations. We also discuss a practical design of upgraded VELO detector for the LHCb experiment employing this approach.
Design and performance of beam test electronics for the PHENIX Multiplicity Vertex Detector
Britton, C.L. Jr.; Bryan, W.L.; Emery, M.S.
1996-12-31
The system architecture and test results of the custom circuits and beam test system for the Multiplicity-Vertex Detector (MVD) for the PHENIX detector collaboration at the Relativistic Heavy Ion Collider (RHIC) are presented in this paper. The final detector per-channel signal processing chain will consist of a preamplifier-gain stage, a current-mode summed multiplicity discriminator, a 64-deep analog memory (simultaneous read-write), a post-memory analog correlator, and a 10-bit 5 {mu}s ADC. The Heap Manager provides all timing control, data buffering, and data formatting for a single 256-channel multi-chip module (MCM). Each chip set is partitioned into 32-channel sets. Beam test (16-cell deep memory) performance for the various blocks will be presented as well as the ionizing radiation damage performance of the 1.2 {mu} n-well CMOS process used for preamplifier fabrication.
A genuinely multi-dimensional upwind cell-vertex scheme for the Euler equations
NASA Technical Reports Server (NTRS)
Powell, Kenneth G.; Van Leer, Bram
1989-01-01
A scheme of solving the two-dimensional Euler equations is developed. The scheme is genuinely two-dimensional. At each iteration, the data are locally decomposed into four variables, allowing convection in appropriate directions. This is done via a cell-vertex scheme with a downwind-weighted distribution step. The scheme is conservative and third-order accurate in space. The derivation and stability analysis of the scheme for the convection equation, and the derivation of the extension to the Euler equations are given. Preconditioning techniques based on local values of the convection speeds are discussed. The scheme for the Euler equations is applied to two channel-flow problems. It is shown to converge rapidly to a solution that agrees well with that of a third-order upwind solver.
Recent results with HV-CMOS and planar sensors for the CLIC vertex detector
NASA Astrophysics Data System (ADS)
Alipour Tehrani, Niloufar
2017-02-01
The physics aims for the future multi-TeV e+e- Compact Linear Collider (CLIC) impose high precision requirements on the vertex detector which has to match the experimental conditions, such as the time structure of the collisions and the presence of beam-induced backgrounds. The principal challenges are: a point resolution of 3 μm , 10 ns time stamping capabilities, low mass (∼0.2% X0 per layer), low power dissipation and pulsed power operation. Recent results of test beam measurements and GEANT4 simulations for assemblies with Timepix3 ASICs and thin active-edge sensors are presented. The 65 nm CLICpix readout ASIC with 25 μm pitch was bump bonded to planar silicon sensors and also capacitively coupled through a thin layer of glue to active HV-CMOS sensors. Test beam results for these two hybridisation concepts are presented.
Vertex/propagator model for least-scattered photons traversing a turbid medium.
Wang, R K; Wilson, M
2001-01-01
The least-scattered photons that arrive at a detector through highly scattering tissues have the potential to image internal structures, functions, and status with high imaging resolution. In contrast, optical diffusing tomography is based on the use of the late-arriving photons, which have been diffusely scattered, leading to very low imaging resolution. A good model of the early-arriving photons, i.e., the least-scattered photons, may have a significant effect on the development of imaging algorithms and a further understanding of imaging mechanisms within current high-resolution optical-imaging techniques. We describe a vertex/propagator approach that attempts to find the probabilities for least-scattered photons traversing a scattering medium, based on analytical expressions for photon histories. The basic mathematical derivations for the model are outlined, and the results are discussed and found to be in very good agreement with those from the Monte Carlo simulations.
A Dummy Scan Flip-Flop Insertion Algorithm based on Driving Vertex
NASA Astrophysics Data System (ADS)
Liu, H. L.; Li, L.; Zhang, Z. X.; Zhou, W. T.
2017-03-01
Commonly termed as Hardware Trojans, is an emerging issue for global hardware security. The research on Hardware Trojan detection is urgent and significant. Dummy Scan Flip-Flop(DSFF) structure could be used to improve the probability of hardware Trojan activation, which is significant to hardware Trojan detection, especially during the design phase. In this express, an algorithm for inserting the DSFF structure based on driving vertex is proposed. According to the experimental results, under the same transition probability threshold(Pth), compared to the state-of-art, the proposed algorithm can reduce both the inserting complexity and the induced area overhead of the DSFF insertion. The maximum area optimization rate can reach 44.8%. The simulation results on S386 and S38584 benchmark circuits indicate that the proposed algorithm can significantly reduce Trojan authentication time by increasing activation probability of hardware Trojan circuits.
Genome sequencing supports a multi-vertex model for Brassiceae species.
Cheng, Feng; Liang, Jianli; Cai, Chengcheng; Cai, Xu; Wu, Jian; Wang, Xiaowu
2017-02-24
The economically important Brassica genus is a good system for studying the evolution of polyploids. Brassica genomes have undergone whole genome triplication (WGT). Subgenome dominance phenomena such as biased gene fractionation and dominant gene expression were observed in tripled genomes of Brassica. The genome of radish (Raphanus sativus), another important crop of tribe Brassiceae, was derived from the same WGT event and shows similar subgenome dominance. These findings and molecular dating indicate that radish occupies a similar evolutionary origin as that of Brassica species. Here, we extended the Brassica "triangle of U" to a multi-vertex model. This model describes the relationships or the potential of using more Brassiceae mesohexaploids in the creation of new allotetraploid oil or vegetable crop species.
A MAPS Based Micro-Vertex Detector for the STAR Experiment
Schambach, Joachim; Anderssen, Eric; Contin, Giacomo; ...
2015-06-18
For the 2014 heavy ion run of RHIC a new micro-vertex detector called the Heavy Flavor Tracker (HFT) was installed in the STAR experiment. The HFT consists of three detector subsystems with various silicon technologies arranged in 4 approximately concentric cylinders close to the STAR interaction point designed to improve the STAR detector’s vertex resolution and extend its measurement capabilities in the heavy flavor domain. The two innermost HFT layers are placed at radii of 2.8 cm and 8 cm from the beam line. These layers are constructed with 400 high resolution sensors based on CMOS Monolithic Active Pixel Sensormore » (MAPS) technology arranged in 10-sensor ladders mounted on 10 thin carbon fiber sectors to cover a total silicon area of 0.16 m2. Each sensor of this PiXeL (“PXL”) sub-detector combines a pixel array of 928 rows and 960 columns with a 20.7 μm pixel pitch together with front-end electronics and zero-suppression circuitry in one silicon die providing a sensitive area of ~3.8 cm2. This sensor architecture features 185.6 μs readout time and 170 mW/cm2 power dissipation. This low power dissipation allows the PXL detector to be air-cooled, and with the sensors thinned down to 50 μm results in a global material budget of only 0.4% radiation length per layer. A novel mechanical approach to detector insertion allows us to effectively install and integrate the PXL sub-detector within a 12 hour period during an on-going multi-month data taking period. The detector requirements, architecture and design, as well as the performance after installation, are presented in this paper.« less
Impact of nonlocal correlations over different energy scales: A dynamical vertex approximation study
NASA Astrophysics Data System (ADS)
Rohringer, G.; Toschi, A.
2016-09-01
In this paper, we investigate how nonlocal correlations affect, selectively, the physics of correlated electrons over different energy scales, from the Fermi level to the band edges. This goal is achieved by applying a diagrammatic extension of dynamical mean field theory (DMFT), the dynamical vertex approximation (D Γ A ), to study several spectral and thermodynamic properties of the unfrustrated Hubbard model in two and three dimensions. Specifically, we focus first on the low-energy regime by computing the electronic scattering rate and the quasiparticle mass renormalization for decreasing temperatures at a fixed interaction strength. This way, we obtain a precise characterization of the several steps through which the Fermi-liquid physics is progressively destroyed by nonlocal correlations. Our study is then extended to a broader energy range, by analyzing the temperature behavior of the kinetic and potential energy, as well as of the corresponding energy distribution functions. Our findings allow us to identify a smooth but definite evolution of the nature of nonlocal correlations by increasing interaction: They either increase or decrease the kinetic energy w.r.t. DMFT depending on the interaction strength being weak or strong, respectively. This reflects the corresponding evolution of the ground state from a nesting-driven (Slater) to a superexchange-driven (Heisenberg) antiferromagnet (AF), whose fingerprints are, thus, recognizable in the spatial correlations of the paramagnetic phase. Finally, a critical analysis of our numerical results of the potential energy at the largest interaction allows us to identify possible procedures to improve the ladder-based algorithms adopted in the dynamical vertex approximation.
A MAPS Based Micro-Vertex Detector for the STAR Experiment
Schambach, Joachim; Anderssen, Eric; Contin, Giacomo; Greiner, Leo; Silber, Joe; Stezelberger, Thorsten; Sun, Xiangming; Szelezniak, Michal; Videbaek, Flemming; Vu, Chinh; Wieman, Howard; Woodmansee, Sam
2015-06-18
For the 2014 heavy ion run of RHIC a new micro-vertex detector called the Heavy Flavor Tracker (HFT) was installed in the STAR experiment. The HFT consists of three detector subsystems with various silicon technologies arranged in 4 approximately concentric cylinders close to the STAR interaction point designed to improve the STAR detector’s vertex resolution and extend its measurement capabilities in the heavy flavor domain. The two innermost HFT layers are placed at radii of 2.8 cm and 8 cm from the beam line. These layers are constructed with 400 high resolution sensors based on CMOS Monolithic Active Pixel Sensor (MAPS) technology arranged in 10-sensor ladders mounted on 10 thin carbon fiber sectors to cover a total silicon area of 0.16 m^{2}. Each sensor of this PiXeL (“PXL”) sub-detector combines a pixel array of 928 rows and 960 columns with a 20.7 μm pixel pitch together with front-end electronics and zero-suppression circuitry in one silicon die providing a sensitive area of ~3.8 cm^{2}. This sensor architecture features 185.6 μs readout time and 170 mW/cm^{2} power dissipation. This low power dissipation allows the PXL detector to be air-cooled, and with the sensors thinned down to 50 μm results in a global material budget of only 0.4% radiation length per layer. A novel mechanical approach to detector insertion allows us to effectively install and integrate the PXL sub-detector within a 12 hour period during an on-going multi-month data taking period. The detector requirements, architecture and design, as well as the performance after installation, are presented in this paper.
NASA Astrophysics Data System (ADS)
Mellbin, Y.; Hallberg, H.; Ristinmaa, M.
2015-06-01
A mesoscale model of microstructure evolution is formulated in the present work by combining a crystal plasticity model with a graph-based vertex algorithm. This provides a versatile formulation capable of capturing finite-strain deformations, development of texture and microstructure evolution through recrystallization. The crystal plasticity model is employed in a finite element setting and allows tracing of stored energy build-up in the polycrystal microstructure and concurrent reorientation of the crystal lattices in the grains. This influences the progression of recrystallization as nucleation occurs at sites with sufficient stored energy and since the grain boundary mobility and energy is allowed to vary with crystallographic misorientation across the boundaries. The proposed graph-based vertex model describes the topological changes to the grain microstructure and keeps track of the grain inter-connectivity. Through homogenization, the macroscopic material response is also obtained. By the proposed modeling approach, grain structure evolution at large deformations as well as texture development are captured. This is in contrast to most other models of recrystallization which are usually limited by assumptions of one or the other of these factors. In simulation examples, the model is in the present study shown to capture the salient features of dynamic recrystallization, including the effects of varying initial grain size and strain rate on the transitions between single-peak and multiple-peak oscillating flow stress behavior. Also the development of recrystallization texture and the influence of different assumptions on orientation of recrystallization nuclei are investigated. Further, recrystallization kinetics are discussed and compared to classical JMAK theory. To promote computational efficiency, the polycrystal plasticity algorithm is parallelized through a GPU implementation that was recently proposed by the authors.
W W V (V =γ , Z ) vertex in the Georgi-Machacek model
NASA Astrophysics Data System (ADS)
Arroyo-Ureña, M. A.; Hernández-Tomé, G.; Tavares-Velasco, G.
2016-11-01
The C P -even static form factors Δ κV' and Δ QV (V =γ , Z ) associated with the W W V vertex are studied in the context of the Georgi-Machacek model (GMM), which predicts nine new scalar bosons accommodated in a singlet, a triplet, and a fiveplet. General expressions for the one-loop contributions to Δ κV' and Δ QV arising from neutral, singly, and doubly charged scalar bosons are obtained in terms of both parametric integrals and Passarino-Veltman scalar functions, which can be numerically evaluated. It is found that the GMM yields 15 (28) distinct contributions to Δ κγ' and Δ Qγ (Δ κZ' and Δ QZ), though several of them are naturally suppressed. A numerical analysis is done in the region of parameter space still consistent with current experimental data and it is found that the largest contributions to Δ κV' arise from Feynman diagrams with two nondegenerate scalar bosons in the loop, with values of the order of a =g2/(96 π2) reached when there is a large splitting between the masses of these scalar bosons. As for Δ QV, it reaches values as large as 10-2a for the lightest allowed scalar bosons, but it decreases rapidly as one of the masses of the scalar bosons becomes large. Among the new contributions of the GMM to the Δ κV' and Δ QV form factors are those induced by the H5±W∓Z vertex, which arises at the tree level and is a unique prediction of this model.
Breast Reconstruction after Mastectomy
Schmauss, Daniel; Machens, Hans-Günther; Harder, Yves
2016-01-01
Breast cancer is the leading cause of cancer death in women worldwide. Its surgical approach has become less and less mutilating in the last decades. However, the overall number of breast reconstructions has significantly increased lately. Nowadays, breast reconstruction should be individualized at its best, first of all taking into consideration not only the oncological aspects of the tumor, neo-/adjuvant treatment, and genetic predisposition, but also its timing (immediate versus delayed breast reconstruction), as well as the patient’s condition and wish. This article gives an overview over the various possibilities of breast reconstruction, including implant- and expander-based reconstruction, flap-based reconstruction (vascularized autologous tissue), the combination of implant and flap, reconstruction using non-vascularized autologous fat, as well as refinement surgery after breast reconstruction. PMID:26835456
Breast reconstruction - natural tissue
... After a mastectomy , some women choose to have cosmetic surgery to remake their breast. This type of surgery ... augmentation surgery Breast reconstruction - implants Mastectomy Patient Instructions Cosmetic breast surgery - discharge Mastectomy and breast reconstruction - what to ask ...
Breast Reconstruction with Implants
... removes your breast to treat or prevent breast cancer. One type of breast reconstruction uses breast implants — silicone devices filled with silicone gel or salt water (saline) — to reshape your breasts. Breast reconstruction ...
Methods of Voice Reconstruction
Chen, Hung-Chi; Kim Evans, Karen F.; Salgado, Christopher J.; Mardini, Samir
2010-01-01
This article reviews methods of voice reconstruction. Nonsurgical methods of voice reconstruction include electrolarynx, pneumatic artificial larynx, and esophageal speech. Surgical methods of voice reconstruction include neoglottis, tracheoesophageal puncture, and prosthesis. Tracheoesophageal puncture can be performed in patients with pedicled flaps such as colon interposition, jejunum, or gastric pull-up or in free flaps such as perforator flaps, jejunum, and colon flaps. Other flaps for voice reconstruction include the ileocolon flap and jejunum. Laryngeal transplantation is also reviewed. PMID:22550443
Reoperative midface reconstruction.
Acero, Julio; García, Eloy
2011-02-01
Reoperative reconstruction of the midface is a challenging issue because of the complexity of this region and the severity of the aesthetic and functional sequela related to the absence or failure of a primary reconstruction. The different situations that can lead to the indication of a reoperative reconstructive procedure after previous oncologic ablative procedures in the midface are reviewed. Surgical techniques, anatomic problems, and limitations affecting the reoperative reconstruction in this region of the head and neck are discussed.
[Breast reconstruction after mastectomy].
Ho Quoc, C; Delay, E
2013-02-01
The mutilating surgery for breast cancer causes deep somatic and psychological sequelae. Breast reconstruction can mitigate these effects and permit the patient to help rebuild their lives. The purpose of this paper is to focus on breast reconstruction techniques and on factors involved in breast reconstruction. The methods of breast reconstruction are presented: objectives, indications, different techniques, operative risks, and long-term monitoring. Many different techniques can now allow breast reconstruction in most patients. Clinical cases are also presented in order to understand the results we expect from a breast reconstruction. Breast reconstruction provides many benefits for patients in terms of rehabilitation, wellness, and quality of life. In our mind, breast reconstruction should be considered more as an opportunity and a positive choice (the patient can decide to do it), than as an obligation (that the patient would suffer). The consultation with the surgeon who will perform the reconstruction is an important step to give all necessary informations. It is really important that the patient could speak again with him before undergoing reconstruction, if she has any doubt. The quality of information given by medical doctors is essential to the success of psychological intervention. This article was written in a simple, and understandable way to help gynecologists giving the best information to their patients. It is maybe also possible to let them a copy of this article, which would enable them to have a written support and would facilitate future consultation with the surgeon who will perform the reconstruction.
PROPOSAL FOR A SILICON VERTEX TRACKER (VTX) FOR THE PHENIX EXPERIMENT.
AKIBA,Y.
2004-03-30
We propose the construction of a Silicon Vertex Tracker (VTX) for the PHENIX experiment at RHIC. The VTX will substantially enhance the physics capabilities of the PHENIX central arm spectrometers. Our prime motivation is to provide precision measurements of heavy-quark production (charm and beauty) in A+A, p(d)+A, and polarized p+p collisions. These are key measurements for the future RHIC program, both for the heavy ion program as it moves from the discovery phase towards detailed investigation of the properties of the dense nuclear medium created in heavy ion collisions, and for the exploration of the nucleon spin-structure functions. In addition, the VTX will also considerably improve other measurements with PHENIX. The main physics topics addressed by the VTX are: (1) Hot and dense strongly interacting matter--Potential enhancement of charm production; Open beauty production; Flavor dependence of jet quenching and QCD energy loss; Accurate charm reference for quarkonium; Thermal dilepton radiation; High p{sub T} phenomena with light flavors above 10-15 GeV/c in p{sub T}; and Upsilon spectroscopy in the e{sup +}e{sup -} decay channel. (2) Gluon spin structure of the nucleon--{Delta}G/G with charm; {Delta}G/G with beauty; and x dependence of {Delta}G/G with {gamma}-jet correlations. (3) Nucleon structure in nuclei--Gluon shadowing over broad x-range. With the present PHENIX detector, heavy-quark production has been measured indirectly through the observation of single electrons. These measurements are inherently limited in accuracy by systematic uncertainties resulting from the large electron background from Dalitz decays and photon conversions. In particular, the statistical nature of the analysis does not allow for a model-independent separation of the charm and beauty contributions. The VTX detector will provide vertex tracking with a resolution of <50 {micro}m over a large coverage both in rapidity (|{eta}| < 1.2) and in azimuthal angle ({Delta}{phi} {approx
Kernel-Based Reconstruction of Graph Signals
NASA Astrophysics Data System (ADS)
Romero, Daniel; Ma, Meng; Giannakis, Georgios B.
2017-02-01
A number of applications in engineering, social sciences, physics, and biology involve inference over networks. In this context, graph signals are widely encountered as descriptors of vertex attributes or features in graph-structured data. Estimating such signals in all vertices given noisy observations of their values on a subset of vertices has been extensively analyzed in the literature of signal processing on graphs (SPoG). This paper advocates kernel regression as a framework generalizing popular SPoG modeling and reconstruction and expanding their capabilities. Formulating signal reconstruction as a regression task on reproducing kernel Hilbert spaces of graph signals permeates benefits from statistical learning, offers fresh insights, and allows for estimators to leverage richer forms of prior information than existing alternatives. A number of SPoG notions such as bandlimitedness, graph filters, and the graph Fourier transform are naturally accommodated in the kernel framework. Additionally, this paper capitalizes on the so-called representer theorem to devise simpler versions of existing Thikhonov regularized estimators, and offers a novel probabilistic interpretation of kernel methods on graphs based on graphical models. Motivated by the challenges of selecting the bandwidth parameter in SPoG estimators or the kernel map in kernel-based methods, the present paper further proposes two multi-kernel approaches with complementary strengths. Whereas the first enables estimation of the unknown bandwidth of bandlimited signals, the second allows for efficient graph filter selection. Numerical tests with synthetic as well as real data demonstrate the merits of the proposed methods relative to state-of-the-art alternatives.
NASA Astrophysics Data System (ADS)
Arfaoui, Makrem; Mansouri, Khalil; Rezgui, Ali
2008-09-01
This Note is devoted to the theoretical study of the elastostatic fields at a vertex notch under general far-field loading conditions. The analysis is based on the finite plane deformation hyperelasticity theory for an incompressible Mooney-Rivlin material. We approach the solution, near the singularity, by a mixed asymptotic development. We show that the shape of the solution depends on the opening angle of the notch and that there is singularity if the notch is concave. Furthermore, we show that a pure loading mode II gives rise to the opening of the notch vertex in contrast to the linear elasticity. To cite this article: M. Arfaoui et al., C. R. Mecanique 336 (2008).
Properties of Linear Integral Equations Related to the Six-Vertex Model with Disorder Parameter
NASA Astrophysics Data System (ADS)
Boos, Hermann; Göhmann, Frank
2011-10-01
One of the key steps in recent work on the correlation functions of the XXZ chain was to regularize the underlying six-vertex model by a disorder parameter α. For the regularized model it was shown that all static correlation functions are polynomials in only two functions. It was further shown that these two functions can be written as contour integrals involving the solutions of a certain type of linear and non-linear integral equations. The linear integral equations depend parametrically on α and generalize linear integral equations known from the study of the bulk thermodynamic properties of the model. In this note we consider the generalized dressed charge and a generalized magnetization density. We express the generalized dressed charge as a linear combination of two quotients of Q-functions, the solutions of Baxter's t-Q-equation. With this result we give a new proof of a lemma on the asymptotics of the generalized magnetization density as a function of the spectral parameter.
Modeling one-mode projection of bipartite networks by tagging vertex information
NASA Astrophysics Data System (ADS)
Qiao, Jian; Meng, Ying-Ying; Chen, Hsinchun; Huang, Hong-Qiao; Li, Guo-Ying
2016-09-01
Traditional one-mode projection models are less informative than their original bipartite networks. Hence, using such models cannot control the projection's structure freely. We proposed a new method for modeling the one-mode projection of bipartite networks, which thoroughly breaks through the limitations of the available one-mode projecting methods by tagging the vertex information of bipartite networks in their one-mode projections. We designed a one-mode collaboration network model by using the method presented in this paper. The simulation results show that our model matches three real networks very well and outperforms the available collaboration network models significantly, which reflects the idea that our method is ideal for modeling one-mode projection models of bipartite graphs and that our one-mode collaboration network model captures the crucial mechanisms of the three real systems. Our study reveals that size growth, individual aging, random collaboration, preferential collaboration, transitivity collaboration and multi-round collaboration are the crucial mechanisms of collaboration networks, and the lack of some of the crucial mechanisms is the main reason that the other available models do not perform as well as ours.
Different vertex parameterizations and propagators for the Δ contribution in π-photoproduction
NASA Astrophysics Data System (ADS)
Quirós, J. J.; Barbero, C.; Jaramillo, D. E.; Mariano, A.
2017-04-01
We evaluate the total cross section for the π-photoproduction process and analyze the behavior of the {{Δ }}(1232) resonance contribution when the photon energy is increased from threshold up to 0.7 GeV. Within this energy range we compare two different parameterizations for the γ N{{Δ }} vertex: the normal parity and the covariant multipole decomposition ones. For completeness, we also compare different versions for the Δ propagator: the first is the dressed propagator obtained including one-loop self-energy contributions (EXACT), the second is the complex mass scheme which consists in replacing {{m}}{{Δ }}\\to {{m}}{{Δ }}-{{i}}{{{Γ }}}{{Δ }}/2 in the bare propagator, and the third is an intermediate approximation between the two previous ones (EXCMS). We conclude that, in order to extend the present calculation to include more energetic resonances in the future and to obtain non-divergent results for the total cross section we will need to use the MD parametrization and the EXCMS propagator.
PROPOSAL FOR A SILICON VERTEX TRACKER (VTX) FOR THE PHENIX EXPERIMENT
AKIBA,Y.
2004-10-01
We propose the construction of a Silicon Vertex Tracker (VTX) for the PHENIX experiment at RHIC. The VTX will substantially enhance the physics capabilities of the PHENIX central arm spectrometers. Our prime motivation is to provide precision measurements of heavy-quark production (charm and beauty) in A+A, p(d)+A, and polarized p+p collisions. These are key measurements for the future RHIC program, both for the heavy ion program as it moves from the discovery phase towards detailed investigation of the properties of the dense nuclear medium created in heavy ion collisions, and for the exploration of the nucleon spin-structure functions. In addition, the VTX will also considerably improve other measurements with PHENIX. The main physics topics addressed by the VTX are: (1) Hot and dense strongly interacting matter--(a) Potential enhancement of charm production, (b) Open beauty production, (c) Flavor dependence of jet quenching and QCD energy loss, (d) Accurate charm reference for quarkonium, (e) Thermal dilepton radiation, (f) High p{sub T} phenomena with light flavors above 10-15 GeV/c in p{sub T}, and (g) Upsilon spectroscopy in the e{sup +}e{sup -} decay channel. (2) Gluon spin structure of the nucleon--(a) {Delta}G/G with charm, (b) {Delta}G/G with beauty, and (c) x dependence of {Delta}G/G with {gamma}-jet correlations. (3) Nucleon structure in nuclei--Gluon shadowing over broad x-range.
Vertex Movement for Mission Status Graphics: A Polar-Star Display
NASA Technical Reports Server (NTRS)
Trujillo, Anna
2002-01-01
Humans are traditionally bad monitors, especially over long periods of time on reliable systems, and they are being called upon to do this more and more as systems become further automated. Because of this, there is a need to find a way to display the monitoring information to the human operator in such a way that he can notice pertinent deviations in a timely manner. One possible solution is to use polar-star displays that will show deviations from normal in a more salient manner. A polar-star display uses a polygon's vertices to report values. An important question arises, though, of how the vertices should move. This experiment investigated two particular issues of how the vertices should move: (1) whether the movement of the vertices should be continuous or discrete and (2) whether the parameters that made up each vertex should always move in one direction regardless of parameter sign or move in both directions indicating parameter sign. The results indicate that relative movement direction is best. Subjects performed better with this movement type and they subjectively preferred it to the absolute movement direction. As for movement type, no strong preferences were shown.
Graphical method for deriving an effective interaction with a new vertex function
Suzuki, K.; Okamoto, R.; Kumagai, H.; Fujii, S.
2011-02-15
Introducing a new vertex function, Z(E), of an energy variable E, we derive a new equation for the effective interaction. The equation is obtained by replacing the Q box in the Krenciglowa-Kuo (KK) method with Z(E). This new approach can be viewed as an extension of the KK method. We show that this equation can be solved both in iterative and noniterative ways. We observe that the iteration procedure with Z(E) brings about fast convergence compared to the usual KK method. It is shown that, as in the KK approach, the procedure of calculating the effective interaction can be reduced to determining the true eigenvalues of the original Hamiltonian H and they can be obtained as the positions of intersections of graphs generated from Z(E). We find that this graphical method yields always precise results and reproduces any of the true eigenvalues of H. The calculation in the present approach can be made regardless of overlaps with the model space and energy differences between unperturbed energies and the eigenvalues of H. We find also that Z(E) is a well-behaved function of E and has no singularity. These characteristics of the present approach ensure stability in actual calculations and would be helpful to resolve some difficulties due to the presence of poles in the Q box. Performing test calculations, we verify numerically theoretical predictions made in the present approach.
Yarmukhamedov, R.; Baye, D.
2011-08-15
Explicit relations between the effective-range expansion and the nuclear vertex constant or asymptotic normalization coefficient (ANC) for the virtual decay B{yields}A+a are derived for an arbitrary orbital momentum together with the corresponding location condition for the (A+a) bound-state energy. They are valid both for the charged case and for the neutral case. Combining these relations with the standard effective-range function up to order six makes it possible to reduce to two the number of free effective-range parameters if an ANC value is known from experiment. Values for the scattering length, effective range, and form parameter are determined in this way for the {sup 16}O+p, {alpha}+t, and {alpha}+{sup 3}He collisions in partial waves where a bound state exists by using available ANCs deduced from experiments. The resulting effective-range expansions for these collisions are valid up to energies larger than 5 MeV.
The beam test measurements of the Belle II vertex detector modules
NASA Astrophysics Data System (ADS)
Bilka, T.
2017-03-01
The Belle II experiment designed to study CP Violation and Beyond Standard model physics at the decays of B-mesons is quickly approaching its first physics run with the SuperKEKB accelerator (Tsukuba, Japan) already under commissioning. To operate in the unique conditions of the Belle II experiment, its vertex detector (VXD) is a six layers silicon detector with two innermost layers of DEPFET active pixel modules and four layers of double-sided strip modules. A section of it will become a commissioning detector for the first collisions of the next-generation high luminosity B-factory. The same setup, from cooling services, mechanical support or sensors and front-end electronics to DAQ, including the software and alignment framework, is tested under an electron beam provided by DESY facilities. We present the basic characteristics of the pixel and strip modules and the setup under test, including software and alignment framework—as close to the final system as possible.
Fletcher, Alexander G; Osborne, James M; Maini, Philip K; Gavaghan, David J
2013-11-01
The dynamic behaviour of epithelial cell sheets plays a central role during development, growth, disease and wound healing. These processes occur as a result of cell adhesion, migration, division, differentiation and death, and involve multiple processes acting at the cellular and molecular level. Computational models offer a useful means by which to investigate and test hypotheses about these processes, and have played a key role in the study of cell-cell interactions. However, the necessarily complex nature of such models means that it is difficult to make accurate comparison between different models, since it is often impossible to distinguish between differences in behaviour that are due to the underlying model assumptions, and those due to differences in the in silico implementation of the model. In this work, an approach is described for the implementation of vertex dynamics models, a discrete approach that represents each cell by a polygon (or polyhedron) whose vertices may move in response to forces. The implementation is undertaken in a consistent manner within a single open source computational framework, Chaste, which comprises fully tested, industrial-grade software that has been developed using an agile approach. This framework allows one to easily change assumptions regarding force generation and cell rearrangement processes within these models. The versatility and generality of this framework is illustrated using a number of biological examples. In each case we provide full details of all technical aspects of our model implementations, and in some cases provide extensions to make the models more generally applicable.
Readout, first- and second-level triggers of the new Belle silicon vertex detector
NASA Astrophysics Data System (ADS)
Friedl, M.; Abe, R.; Abe, T.; Aihara, H.; Asano, Y.; Aso, T.; Bakich, A.; Browder, T.; Chang, M. C.; Chao, Y.; Chen, K. F.; Chidzik, S.; Dalseno, J.; Dowd, R.; Dragic, J.; Everton, C. W.; Fernholz, R.; Fujii, H.; Gao, Z. W.; Gordon, A.; Guo, Y. N.; Haba, J.; Hara, K.; Hara, T.; Harada, Y.; Haruyama, T.; Hasuko, K.; Hayashi, K.; Hazumi, M.; Heenan, E. M.; Higuchi, T.; Hirai, H.; Hitomi, N.; Igarashi, A.; Igarashi, Y.; Ikeda, H.; Ishino, H.; Itoh, K.; Iwaida, S.; Kaneko, J.; Kapusta, P.; Karawatzki, R.; Kasami, K.; Kawai, H.; Kawasaki, T.; Kibayashi, A.; Koike, S.; Korpar, S.; Križan, P.; Kurashiro, H.; Kusaka, A.; Lesiak, T.; Limosani, A.; Lin, W. C.; Marlow, D.; Matsumoto, H.; Mikami, Y.; Miyake, H.; Moloney, G. R.; Mori, T.; Nakadaira, T.; Nakano, Y.; Natkaniec, Z.; Nozaki, S.; Ohkubo, R.; Ohno, F.; Okuno, S.; Onuki, Y.; Ostrowicz, W.; Ozaki, H.; Peak, L.; Pernicka, M.; Rosen, M.; Rozanska, M.; Sato, N.; Schmid, S.; Shibata, T.; Stamen, R.; Stanič, S.; Steininger, H.; Sumisawa, K.; Suzuki, J.; Tajima, H.; Tajima, O.; Takahashi, K.; Takasaki, F.; Tamura, N.; Tanaka, M.; Taylor, G. N.; Terazaki, H.; Tomura, T.; Trabelsi, K.; Trischuk, W.; Tsuboyama, T.; Uchida, K.; Ueno, K.; Ueno, K.; Uozaki, N.; Ushiroda, Y.; Vahsen, S.; Varner, G.; Varvell, K.; Velikzhanin, Y. S.; Wang, C. C.; Wang, M. Z.; Watanabe, M.; Watanabe, Y.; Yamada, Y.; Yamamoto, H.; Yamashita, Y.; Yamashita, Y.; Yamauchi, M.; Yanai, H.; Yang, R.; Yasu, Y.; Yokoyama, M.; Ziegler, T.; Žontar, D.
2004-12-01
A major upgrade of the Silicon Vertex Detector (SVD 2.0) of the Belle experiment at the KEKB factory was installed along with new front-end and back-end electronics systems during the summer shutdown period in 2003 to cope with higher particle rates, improve the track resolution and meet the increasing requirements of radiation tolerance. The SVD 2.0 detector modules are read out by VA1TA chips which provide "fast or" (hit) signals that are combined by the back-end FADCTF modules to coarse, but immediate level 0 track trigger signals at rates of several tens of a kHz. Moreover, the digitized detector signals are compared to threshold lookup tables in the FADCTFs to pass on hit information on a single strip basis to the subsequent level 1.5 trigger system, which reduces the rate below the kHz range. Both FADCTF and level 1.5 electronics make use of parallel real-time processing in Field Programmable Gate Arrays (FPGAs), while further data acquisition and event building is done by PC farms running Linux. The new readout system hardware is described and the first results obtained with cosmics are shown.
Controllability and observability analysis for vertex domination centrality in directed networks
Wang, Bingbo; Gao, Lin; Gao, Yong; Deng, Yue; Wang, Yu
2014-01-01
Topological centrality is a significant measure for characterising the relative importance of a node in a complex network. For directed networks that model dynamic processes, however, it is of more practical importance to quantify a vertex's ability to dominate (control or observe) the state of other vertices. In this paper, based on the determination of controllable and observable subspaces under the global minimum-cost condition, we introduce a novel direction-specific index, domination centrality, to assess the intervention capabilities of vertices in a directed network. Statistical studies demonstrate that the domination centrality is, to a great extent, encoded by the underlying network's degree distribution and that most network positions through which one can intervene in a system are vertices with high domination centrality rather than network hubs. To analyse the interaction and functional dependence between vertices when they are used to dominate a network, we define the domination similarity and detect significant functional modules in glossary and metabolic networks through clustering analysis. The experimental results provide strong evidence that our indices are effective and practical in accurately depicting the structure of directed networks. PMID:24954137
Magnetoresistance in High-Tc Superconductors: The Role of Vertex Corrections
NASA Astrophysics Data System (ADS)
Kontani, Hiroshi
2001-07-01
In high-Tc cuprates, the orbital magnetoresistance in plane (Δρ/ρ) is anomalously enhanced at lower tempemeratures compared with conventional Fermi liquids, and thus Kohler's rule is strongly violated. Moreover, it should be noted that an intimate relation between Δρ/ρ and the Hall coefficient (RH), Δρ/ρ∝(RH/ρ)2, holds well experimentally, and is called the “modified Kohler's rule”. In this letter, we study this long-standing problem in terms of the nearly antiferromagnetic (AF) Fermi liquid. We analyze the exact expression for Δρ/ρ by including the vertex corrections (VC's) to keep the conservation laws, and find the approximate relation Δρ/ρ∝ξAF4 ρ-2 ·H2 (ξAF being the AF correlation length) in the presence of AF fluctuations. The factor ξAF4, which comes from the VC's for the current, gives the additional temperature dependence. By taking account of the relation RH ∝ξAF2 [Kontani et al.: Phys. Rev. B 59 (1999) 14723], we can naturally explain the modified Kohler's rule. In conclusion, based on the Fermi liquid theory, the famous seemingly non-Fermi liquid behaviors of RH and Δρ/ρ in high-Tc cuprates are naturally understood on an equal footing.
A chiral 60-metal sodalite cage featuring 24 vertex-sharing [Er4(mu3-OH)4] cubanes.
Kong, Xiang-Jian; Wu, Yinglan; Long, La-Sheng; Zheng, Lan-Sun; Zheng, Zhiping
2009-05-27
A chiral, cagelike, high-nuclearity lanthanide hydroxide cluster containing 60 Er(III) ions is reported. The cluster core possesses a fascinating sodalite-like structure with 24 vertex-sharing cubane-like [Er(4)(mu(3)-OH)(4)](8+) units. The hexagonal face of the sodalite cage features a templating mu(6)-CO(3)(2-) ion. Magnetic studies revealed weak antiferromagnetic interactions.
Surgical reconstruction of TMJ.
Ramil Novo, V M; Garcìa, A G; Berini Aytès, L; Escoda, C G
1999-01-01
Certain situations and pathological processes that arise with temporomandibular joint destruction can only be resolved with surgical reconstructive procedures in order to attempt a functional and anatomical rehabilitation of this joint. Many of these situations can be surgically treated with the patient's own autologous tissues. However, in some patients reconstruction is complex and the use of autologous tissues is unadvisable whereas reconstruction utilizing alloplastic materials may be an appropriate alternative. The following report describes 4 clinical cases in which autologous grafts or Christensen joint prosthesis are employed in temporomandibular joint reconstruction.
NASA Astrophysics Data System (ADS)
Nelson, Timothy Knight
We describe measurements of the branching ratios
Reconstruction of Japanese Vowels.
ERIC Educational Resources Information Center
Aoki, Haruo
1972-01-01
This paper discusses the relationship between linguistic reconstructions and their historical validity using the case of Old Japanese (8th century A.D.) vowels as an example. Reconstructions throughout the paper include only those cases in which the modern reflexes and phonological correspondences between two or more genetically related languages…
ERIC Educational Resources Information Center
Phillips, David; And Others
This report describes the main questions that various international agencies must address in order to reconstruct education in countries that have experienced crisis. "Crisis" is defined as war, natural disaster, and extreme political and economic upheaval. Many of the problems of educational reconstruction with which the Allies contended in…
Recent progress in sensor- and mechanics-R&D for the Belle II Silicon Vertex Detector
NASA Astrophysics Data System (ADS)
Bergauer, T.; Doljeschi, P.; Frankenberger, A.; Friedl, M.; Gfall, I.; Irmler, C.; Onuki, Y.; Smiljic, D.; Tsuboyama, T.; Valentan, M.
2013-08-01
The Belle experiment at the KEKB electron/positron collider in Tsukuba (Japan) was successfully running for more than ten years. A major update of the machine to SuperKEKB is now foreseen until 2015, aiming a peak luminosity which is 40 times the peak value of the previous system. This also requires a redesign of the Belle detector (leading to Belle II) and especially its Silicon Vertex Detector (SVD), which surrounds the beam pipe. The future Belle II SVD will consist of four layers of double-sided silicon strip sensors based on 6 in. silicon wafers. Three of the four layers will be equipped with trapezoidal sensors in the slanted forward region. Moreover, two inner layers with pixel detectors based on DEPFET technology will complement the SVD as innermost detector. Since the KEKB-factory operates at relatively low energy, material inside the active volume has to be minimized in order to reduce multiple scattering. This can be achieved by arranging the sensors in the so-called "Origami chip-on-sensor concept", and a very light-weight mechanical support structure made from carbon fiber reinforced Airex foam. Moreover, CO2 cooling for the front-end chips will ensure high efficiency at minimum material budget. In this paper, an overview of the future Belle II SVD design will be given, covering the silicon sensors, the readout electronics and the mechanics. A strong emphasis will be given to our R&D work on double-sided sensors where different p-stop layouts for the n-side of the detectors were compared. Moreover, this paper gives updated numbers for the mechanical dimensions of the ladders and their radii.
The TORCH time-of-flight detector for particle identification and photon vertex association
NASA Astrophysics Data System (ADS)
Castillo García, L.; Brook, N.; Cussans, D.; Föhl, K.; Forty, R.; Frei, C.; Gao, R.; Gys, T.; Harnew, N.; Piedigrossi, D.; Rademacker, J.; Ros García, A.; van Dijk, M.
2017-02-01
TORCH (Time Of internally Reflected CHerenkov light) is a novel time-of-flight detector, designed to provide π /K/p particle identification up to 0~ 1 GeV/c momentum and beyond. To achieve this, a time resolution of ~ 15 ps combining information from 0~ 3 detected photons is required over a 10 m flight path. Large areas can be covered with TORCH, nominally up to 30 m2. One such application is for the LHCb experiment, to complement the particle identification capabilities of its RICH detectors. TORCH has a DIRC-like construction with 10 mm-thick synthetic amorphous fused-silica plates as a radiator. Cherenkov photons propagate by total internal reflection to the plate edges and there are focussed onto an array of position-sensitive photodetectors. Custom-built micro-channel plate photo-multipliers (MCP-PMTs) are being developed in collaboration with industry to provide the lifetime, granularity and time resolution to meet the TORCH specifications. In the present paper, laboratory tests of the MCP-PMTs developed for TORCH and its readout electronics are presented. Test beam measurements of a prototype TORCH detector in a low-momentum mixed beam of pions and protons are highlighted. Time resolutions for individual photons approaching 100 ps is achieved, after correction for dispersion effects in the quartz medium. In addition to the particle identification capabilities, the high-precision timing information that TORCH provides could be used at the high-luminosity LHC to associate high-energy photons with the correct primary interaction vertex amongst the many expected.
Anterolateral Ligament Reconstruction
Zordan, J.; Etcheto, H. Rivarola; Blanchod, C. Collazo; Palanconi, M.; Salinas, E. Álvarez; Autorino, CM; Escobar, G.
2017-01-01
Anterior cruciate ligament (ACL) reconstruction is a common procedure in daily practice with 75 to 97% excellent long-term results. But in certain cases, some patients perceive rotational instability, for this reason the revision rate can be 10 to 15%. Objectives: evaluate functional outcome in revisions of ACL reconstruction associated with ALL. Methods: Between July 2015 and February 2016 (11 knees) Eleven Revision ACL reconstruction were performed with ALL with double incision technique performed by the same surgical team. Inclusion criteria were: ACL reconstruction failures with a grade 2 or 3 Lachman test, a grade 3 pivot-shift without other ligamentary injury lesions associated and complete range of motion. Results: The concept of rotational instability associated with ACL injury has been described more than a decade ago. However, there is no consensus on how to quantify rotational instability in ACL injuries; so when associating an extracapsular technique. Currently there is a lack of high-level evidence comparing isolated ACL repair and associated with the modified reconstruction of ALL that allows us to define therapeutic approaches. The ALL reconstruction associate an ACL reconstruction remains a matter of study. Conclusion: We obtain excellent results in antero – posterior and rotational stability after performing the procedure.
Nasal reconstruction after epithelioma.
Rodríguez-Camps, S
2001-01-01
In this paper we present our procedure for the treatment, histopathological diagnosis, and resection of skin cancer in the nasal pyramid and its subsequent reconstruction. Because we are dealing with the most important anatomical feature of the face our goal is an aesthetic reconstruction [2,4] according to the anatomical subunits criterion of Burget [3]. First, a histopathological diagnosis is made to determine the nature of the tumor. Then, we proceed with the resection according to the Mohs Micrographic Surgery [1,5,7]. Then we begin with the first step of the nasal reconstruction.
Craniofacial reconstruction - series (image)
Patients requiring craniofacial reconstruction have: birth defects (such as hypertelorism, Crouzon's disease, Apert's syndrome) injuries to the head, face, or jaws (maxillofacial) tumors deformities caused by treatments of tumors
... surgery to allow for better healing. You need radiation therapy. Many doctors recommend that women not have immediate ... al. Ischemic complications in pedicle, free, and muscle sparing transverse rectus abdominis myocutaneous flaps for breast reconstruction. ...
Reconstruction of Mandibular Defects
Chim, Harvey; Salgado, Christopher J.; Mardini, Samir; Chen, Hung-Chi
2010-01-01
Defects requiring reconstruction in the mandible are commonly encountered and may result from resection of benign or malignant lesions, trauma, or osteoradionecrosis. Mandibular defects can be classified according to location and extent, as well as involvement of mucosa, skin, and tongue. Vascularized bone flaps, in general, provide the best functional and aesthetic outcome, with the fibula flap remaining the gold standard for mandible reconstruction. In this review, we discuss classification and approach to reconstruction of mandibular defects. We also elaborate upon four commonly used free osteocutaneous flaps, inclusive of fibula, iliac crest, scapula, and radial forearm. Finally, we discuss indications and use of osseointegrated implants as well as recent advances in mandibular reconstruction. PMID:22550439
Breast reconstruction - implants
... cosmetic surgery after breast cancer can improve your sense of well-being and your quality of life. Alternative Names Breast implants surgery References Roehl KR, Wilhelmi BJ, Phillips LG. Breast reconstruction. ...
NASA Astrophysics Data System (ADS)
Altmeyer, Michaela; Guterding, Daniel; Hirschfeld, P. J.; Maier, Thomas A.; Valentí, Roser; Scalapino, Douglas J.
2016-12-01
In the framework of a multiorbital Hubbard model description of superconductivity, a matrix formulation of the superconducting pairing interaction that has been widely used is designed to treat spin, charge, and orbital fluctuations within a random phase approximation (RPA). In terms of Feynman diagrams, this takes into account particle-hole ladder and bubble contributions as expected. It turns out, however, that this matrix formulation also generates additional terms which have the diagrammatic structure of vertex corrections. Here we examine these terms and discuss the relationship between the matrix-RPA superconducting pairing interaction and the Feynman diagrams that it sums.
Bernardin, J.D.; Bosze, E.; Boissevain, J.; Simon-Gillo, J.
1997-07-01
This report presents a summary of an experimental investigation of an electronics air cooling system for the multiplicity and vertex detector (MVD), a device used to determine and characterize the collision location of two accelerated heavy ions. Measurements of the flow rates of the cooling air and the temperatures of the air and electronic components were used to assess and optimize the performance of the proposed air cooling system, identify potential assembly problems and system limitations, and provide the necessary information for designing and sizing the final MVD cooling system components.
Lining in nasal reconstruction.
Haack, Sebastian; Fischer, Helmut; Gubisch, Wolfgang
2014-06-01
Restoring nasal lining is one of the essential parts during reconstruction of full-thickness defects of the nose. Without a sufficient nasal lining the whole reconstruction will fail. Nasal lining has to sufficiently cover the shaping subsurface framework. But in addition, lining must not compromise or even block nasal ventilation. This article demonstrates different possibilities of lining reconstruction. The use of composite grafts for small rim defects is described. The limits and technical components for application of skin grafts are discussed. Then the advantages and limitations of endonasal, perinasal, and hingeover flaps are demonstrated. Strategies to restore lining with one or two forehead flaps are presented. Finally, the possibilities and technical aspects to reconstruct nasal lining with a forearm flap are demonstrated. Technical details are explained by intraoperative pictures. Clinical cases are shown to illustrate the different approaches and should help to understand the process of decision making. It is concluded that although the lining cannot be seen after reconstruction of the cover it remains one of the key components for nasal reconstruction. When dealing with full-thickness nasal defects, there is no way to avoid learning how to restore nasal lining.
Efficient holoscopy image reconstruction.
Hillmann, Dierck; Franke, Gesa; Lührs, Christian; Koch, Peter; Hüttmann, Gereon
2012-09-10
Holoscopy is a tomographic imaging technique that combines digital holography and Fourier-domain optical coherence tomography (OCT) to gain tomograms with diffraction limited resolution and uniform sensitivity over several Rayleigh lengths. The lateral image information is calculated from the spatial interference pattern formed by light scattered from the sample and a reference beam. The depth information is obtained from the spectral dependence of the recorded digital holograms. Numerous digital holograms are acquired at different wavelengths and then reconstructed for a common plane in the sample. Afterwards standard Fourier-domain OCT signal processing achieves depth discrimination. Here we describe and demonstrate an optimized data reconstruction algorithm for holoscopy which is related to the inverse scattering reconstruction of wavelength-scanned full-field optical coherence tomography data. Instead of calculating a regularized pseudoinverse of the forward operator, the recorded optical fields are propagated back into the sample volume. In one processing step the high frequency components of the scattering potential are reconstructed on a non-equidistant grid in three-dimensional spatial frequency space. A Fourier transform yields an OCT equivalent image of the object structure. In contrast to the original holoscopy reconstruction with backpropagation and Fourier transform with respect to the wavenumber, the required processing time does neither depend on the confocal parameter nor on the depth of the volume. For an imaging NA of 0.14, the processing time was decreased by a factor of 15, at higher NA the gain in reconstruction speed may reach two orders of magnitude.
A neural network on FPGAs for the z-vertex track trigger in Belle II
NASA Astrophysics Data System (ADS)
Baehr, S.; Skambraks, S.; Neuhaus, S.; Kiesling, C.; Becker, J.
2017-03-01
Background originating from events outside of the interaction point is going to play a major role in the upcoming Belle II experiment. In order to reduce this background a track trigger based on the reconstruction of an event's z position is employed on FPGAs. This paper presents the architecture and implementation of neural networks and supporting preprocessing that is going to be used at the upcoming cosmic ray test of Belle II. By using hit information from simulations, figures of merit like latency and resource demand are presented.
NASA Astrophysics Data System (ADS)
Mellbin, Y.; Hallberg, H.; Ristinmaa, M.
2016-10-01
A multiscale modeling framework, combining a graph-based vertex model of microstructure evolution with a GPU-parallelized crystal plasticity model, was recently proposed by the authors. Considering hot rolling of copper, the full capabilities of the model are demonstrated in the present work. The polycrystal plasticity model captures the plastic response and the texture evolution during materials processing while the vertex model provides central features of grain structure evolution through dynamic recrystallization, such as nucleation and growth of individual crystals. The multiscale model makes it possible to obtain information regarding grain size and texture development throughout the workpiece, capturing the effects of recrystallization and heterogeneous microstructure evolution. Recognizing that recrystallization is a highly temperature dependent phenomenon, simulations are performed at different process temperatures. The results show that the proposed modeling framework is capable of simultaneously capturing central aspects of material behavior at both the meso- and macrolevel. Detailed investigation of the evolution of texture, grain size distribution and plastic deformation during the different processing conditions are performed, using the proposed model. The results show a strong texture development, but almost no recrystallization, for the lower of the investigated temperatures, while at higher temperatures an increased recrystallization is shown to weaken the development of a typical rolling texture. The simulations also show the influence of the shear deformation close to the rolling surface on both texture development and recrystallization.
NASA Astrophysics Data System (ADS)
Katanin, A.
2016-01-01
In this paper, we consider the possibility of chiral (charge or spin density wave) symmetry breaking in graphene due to long-range Coulomb interaction by comparing the results of the Bethe-Salpeter and functional renormalization-group approaches. The former approach performs a summation of ladder diagrams in the particle-hole channel and reproduces the results of the Schwinger-Dyson approach for the critical interaction strength of the quantum phase transition. The renormalization-group approach combines the effect of different channels and allows to study the role of vertex corrections. The critical interaction strength, which is necessary to induce the symmetry breaking in the latter approach, is found in the static approximation to be αc=e2/(ɛ vF) ≈1.05 without considering the Fermi velocity renormalization, and αc=3.7 with accounting the renormailzation of the Fermi velocity. The latter value is expected to be, however, reduced, when the dynamic screening effects are taken into account, yielding the critical interaction, which may be comparable to the one in freely suspended graphene. We show that the vertex corrections are crucially important to obtain the mentioned values of critical interactions.
Augmented Likelihood Image Reconstruction.
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.
Lateral Abdominal Wall Reconstruction
Baumann, Donald P.; Butler, Charles E.
2012-01-01
Lateral abdominal wall (LAW) defects can manifest as a flank hernias, myofascial laxity/bulges, or full-thickness defects. These defects are quite different from those in the anterior abdominal wall defects and the complexity and limited surgical options make repairing the LAW a challenge for the reconstructive surgeon. LAW reconstruction requires an understanding of the anatomy, physiologic forces, and the impact of deinnervation injury to design and perform successful reconstructions of hernia, bulge, and full-thickness defects. Reconstructive strategies must be tailored to address the inguinal ligament, retroperitoneum, chest wall, and diaphragm. Operative technique must focus on stabilization of the LAW to nonyielding points of fixation at the anatomic borders of the LAW far beyond the musculofascial borders of the defect itself. Thus, hernias, bulges, and full-thickness defects are approached in a similar fashion. Mesh reinforcement is uniformly required in lateral abdominal wall reconstruction. Inlay mesh placement with overlying myofascial coverage is preferred as a first-line option as is the case in anterior abdominal wall reconstruction. However, interposition bridging repairs are often performed as the surrounding myofascial tissue precludes a dual layered closure. The decision to place bioprosthetic or prosthetic mesh depends on surgeon preference, patient comorbidities, and clinical factors of the repair. Regardless of mesh type, the overlying soft tissue must provide stable cutaneous coverage and obliteration of dead space. In cases where the fasciocutaneous flaps surrounding the defect are inadequate for closure, regional pedicled flaps or free flaps are recruited to achieve stable soft tissue coverage. PMID:23372458
Reconstructing the astronomical heritage
NASA Astrophysics Data System (ADS)
Planesas, Pere
2011-06-01
Studies of the astronomical heritage can deal with the ancient astronomical knowledge, traditions and myths, as well as with old instruments and observatories. It is urgent to work for their recovery, before they are definitely forgoten, lost or destroyed. On the cultural side, the Joint ALMA Observatory is sponsoring the study of the local cosmology and sky of the indigenous people living in the region where ALMA is currently being build. In the case of ancient instruments, several success stories already exist, the most recent one being the reconstruction of the Madrid 25ft Herschel telescope. Examples of notable instruments pending reconstruction are listed.
Espinoza, Gabriela Mabel; Prost, Angela Michelle
2016-05-01
Reconstruction of the upper eyelid is complicated because the eyelid must retain mobility, flexibility, function, and a suitable mucosal surface over the delicate cornea. Defects of the upper eyelid may be due to congenital defects or traumatic injury or follow oncologic resection. This article focuses on reconstruction due to loss of tissue. Multiple surgeries may be needed to reach the desired results, addressing loss of tissue and then loss of function. Each defect is unique and the laxity and availability of surrounding tissue vary. Knowing the most common techniques for repair assists surgeons in the multifaceted planning that takes place.
Reconstruction of the Intranasal Lining.
Zenga, Joseph; Chi, John J
2017-02-01
Reconstruction of full-thickness nasal defects has been the subject of surgical inquiry and innovation for over 2,000 years. The replacement of the internal nasal lining is a critical feature of complex nasal reconstruction. Successful reconstruction can prevent cicatricial contraction, external distortion, and internal stenosis. An array of reconstructive possibilities has been described, including cutaneous, mucosal, and fascial options. The challenge to the reconstructive surgeon is to select the repair that maximizes internal stability, while maintaining a patent nasal airway, minimizing morbidity, and meeting patient expectations. This article reviews the options available for the reconstruction of the intranasal lining.
Reconstructing Progressive Education
ERIC Educational Resources Information Center
Kaplan, Andy
2013-01-01
The work of Colonel Francis W. Parker, the man whom Dewey called "the father of progressive education," provides a starting point for reconstructing the loose ambiguities of progressive education into a coherent social and educational philosophy. Although progressives have claimed their approach is more humane and sensitive to children, we need…
Preparing for Breast Reconstruction Surgery
... Cancer Breast Reconstruction Surgery Preparing for Breast Reconstruction Surgery Your surgeon can help you know what to ... The plan for follow-up Costs Understanding your surgery costs Health insurance policies often cover most or ...
NASA Astrophysics Data System (ADS)
Ono, Shun; Togawa, Manabu; Tsuji, Ryoji; Mori, Teppei; Yamada, Miho; Arai, Yasuo; Tsuboyama, Toru; Hanagaki, Kazunori
2017-02-01
We have been developing a new monolithic pixel sensor with silicon-on-insulator (SOI) technology for the International Linear Collider (ILC) vertex detector system. The SOI monolithic pixel detector is realized using standard CMOS circuits fabricated on a fully depleted sensor layer. The new SOI sensor SOFIST can store both the position and timing information of charged particles in each 20×20 μm2 pixel. The position resolution is further improved by the position weighted with the charges spread to multiple pixels. The pixel also records the hit timing with an embedded time-stamp circuit. The sensor chip has column-parallel analog-to-digital conversion (ADC) circuits and zero-suppression logic for high-speed data readout. We are designing and evaluating some prototype sensor chips for optimizing and minimizing the pixel circuit.
Determination of A FB b at the Z pole using inclusive charge reconstruction and lifetime tagging
NASA Astrophysics Data System (ADS)
DELPHI Collaboration
2005-03-01
A novel high precision method measures the b-quark forward-backward asymmetry at the Z pole on a sample of 3,560,890 hadronic events collected with the DELPHI detector in 1992 to 2000. An enhanced impact parameter tag provides a high purity b sample. For event hemispheres with a reconstructed secondary vertex the charge of the corresponding quark or anti-quark is determined using a neural network which combines in an optimal way the full available charge information from the vertex charge, the jet charge and from identified leptons and hadrons. The probability of correctly identifying b-quarks and anti-quarks is measured on the data themselves comparing the rates of double hemisphere tagged like-sign and unlike-sign events. The b-quark forward-backward asymmetry is determined from the differential asymmetry, taking small corrections due to hemisphere correlations and background contributions into account. The results for different centre-of-mass energies are: A_{FB}^{{b}} (89.449 GeV) = 0.0637 ± 0.0143(stat.) ± 0.0017(syst.)
Controversies in Parotid Defect Reconstruction.
Tamplen, Matthew; Knott, P Daniel; Fritz, Michael A; Seth, Rahul
2016-08-01
Reconstruction of the parotid defect is a complex topic that encompasses restoration of both facial form and function. The reconstructive surgeon must consider facial contour, avoidance of Frey syndrome, skin coverage, tumor surveillance, potential adjuvant therapy, and facial reanimation when addressing parotid defects. With each defect there are several options within the reconstructive ladder, creating controversies regarding optimal management. This article describes surgical approaches to reconstruction of parotid defects, highlighting areas of controversy.
Hu, J.; Wu, L.; Kuttiyiel, K.; ...
2016-06-30
We describe a new class of core-shell nanoparticle catalysts having edges and vertexes covered by refractory metal oxide that preferentially segregates onto these catalyst sites. The monolayer shell is deposited on the oxidefree core atoms. The oxide on edges and vertexes induces high catalyst’s stability and activity. The catalyst and synthesis are exemplified by fabrication of Au nanoparticles doped by Ti atoms that segregate as oxide onto low–coordination sites of edges and vertexes. Pt monolayer shell deposited on Au sites has the mass and specific activities for the oxygen reduction reaction about 13 and 5 times higher than those ofmore » commercial Pt/C catalysts. The durability tests show no activity loss after 10000 potential cycles from 0.6 to 1.0V. The superior activity and durability of the Ti-Au@Pt catalyst originate from protective Ti oxide located at the most dissolution-prone edge and vertex sites, and Au-supported active and stable Pt shell.« less
Hu, J.; Wu, L.; Kuttiyiel, K.; Goodman, K. R.; Zhang, C.; Zhu, Y.; Vukmirovic, M. B.; White, M. G.; Sasaki, K.; Adzic, R. R.
2016-06-30
We describe a new class of core-shell nanoparticle catalysts having edges and vertexes covered by refractory metal oxide that preferentially segregates onto these catalyst sites. The monolayer shell is deposited on the oxidefree core atoms. The oxide on edges and vertexes induces high catalyst’s stability and activity. The catalyst and synthesis are exemplified by fabrication of Au nanoparticles doped by Ti atoms that segregate as oxide onto low–coordination sites of edges and vertexes. Pt monolayer shell deposited on Au sites has the mass and specific activities for the oxygen reduction reaction about 13 and 5 times higher than those of commercial Pt/C catalysts. The durability tests show no activity loss after 10000 potential cycles from 0.6 to 1.0V. The superior activity and durability of the Ti-Au@Pt catalyst originate from protective Ti oxide located at the most dissolution-prone edge and vertex sites, and Au-supported active and stable Pt shell.
Deng, Qingqiong; Zhou, Mingquan; Wu, Zhongke; Shui, Wuyang; Ji, Yuan; Wang, Xingce; Liu, Ching Yiu Jessica; Huang, Youliang; Jiang, Haiyan
2016-02-01
Craniofacial reconstruction recreates a facial outlook from the cranium based on the relationship between the face and the skull to assist identification. But craniofacial structures are very complex, and this relationship is not the same in different craniofacial regions. Several regional methods have recently been proposed, these methods segmented the face and skull into regions, and the relationship of each region is then learned independently, after that, facial regions for a given skull are estimated and finally glued together to generate a face. Most of these regional methods use vertex coordinates to represent the regions, and they define a uniform coordinate system for all of the regions. Consequently, the inconsistence in the positions of regions between different individuals is not eliminated before learning the relationships between the face and skull regions, and this reduces the accuracy of the craniofacial reconstruction. In order to solve this problem, an improved regional method is proposed in this paper involving two types of coordinate adjustments. One is the global coordinate adjustment performed on the skulls and faces with the purpose to eliminate the inconsistence of position and pose of the heads; the other is the local coordinate adjustment performed on the skull and face regions with the purpose to eliminate the inconsistence of position of these regions. After these two coordinate adjustments, partial least squares regression (PLSR) is used to estimate the relationship between the face region and the skull region. In order to obtain a more accurate reconstruction, a new fusion strategy is also proposed in the paper to maintain the reconstructed feature regions when gluing the facial regions together. This is based on the observation that the feature regions usually have less reconstruction errors compared to rest of the face. The results demonstrate that the coordinate adjustments and the new fusion strategy can significantly improve the
Medial Patellofemoral Ligament Reconstruction
Palacios, Jose Antonio; Yacuzzi, Carlos; Oñativia, Jose I.; Zicaro, Juan Pablo; Costa-Paz, Matias
2017-01-01
Objectives: Recurrent patellofemoral dislocation is usually a multifactorial pathology. Different surgical techniques have been described according to the etiology of dislocation. In absence of a severe malalignment or an anatomical patellofemoral dysplasia, reconstruction of Medial Patello-femoral Ligament (MPFL) can restore the normal tracking of the patella, avoiding lateral excursion. The purpose of this study was to evaluate clinical results and complications in patients who underwent a MPFL reconstruction. Methods: We retrospectively evaluated 19 patients who underwent an anatomic MPFL reconstruction using autologous semitendinosus graft between 2007 and 2012. Exclusion criteria were patients with less than three years of follow-up and those with an associated procedure such as distal realignment or trochleoplasty. Clinical outcomes were measured using Kujala score and return to sport rate. We registered the postoperative complications and recurrence rate. Results: Nine patients were men and 10 women with a mean age of 25 years. Average follow-up was 5.8 years. Nine patients (47.4%) returned to their previous sport level, 8 (42.1%) changed to another sport or decreased their level and 2 (10.5%) were unable to practice any sports at all. Kujala score improvement was from 62.8 preoperative to 88.8 postoperative. One patient decreased the Kujala score. Eighty-nine percent of patients were satisfied with their outcome. One patient had a patellar fracture and four developed an arthrofibrosis and required mobilization under anesthesia. No recurrences were registered. Conclusion: Isolated MPFL reconstruction for recurrent patellofemoral dislocation is an effective alternative in absence of severe malalignment or anatomical dysplasia. Although no recurrences where registered at minimum 3-year follow-up, almost half of the patients were not able to return to their previous sport level.
Kinky tomographic reconstruction
Hanson, K.M.; Cunningham, G.S.; Bilisoly, R.L.
1996-05-01
We address the issue of how to make decisions about the degree of smoothness demanded of a flexible contour used to model the boundary of a 2D object. We demonstrate the use of a Bayesian approach to set the strength of the smoothness prior for a tomographic reconstruction problem. The Akaike Information Criterion is used to determine whether to allow a kink in the contour.
Temporal Surface Reconstruction
1991-05-03
sequence of images. Structure information can be recovered from images through a number of visual mechanisms such as shading, motion and stereo . Image...stages which are repeated (continued on back) 14. SUBJECT TERMS (key words) 1S. NUMBER OF PAGES 3D reconstruction structure estimation temporal visio 149...such as shading, motion and stereo . Image information is commonly available in a time-continuous fashion and this work proposes a method for estimating
World reconstruction in psychotherapy.
Bergner, Raymond M
2005-01-01
The purpose of this article is to articulate how we, as psychotherapists, can transform the worlds of our clients. In part one of the article, the concept of "world," the dynamics of how worlds operate, and the clinically relevant notions of "problematic worlds" and "impossible worlds" are explicated. In part two, therapeutic recommendations for helping clients to reconstruct their worlds are presented, with special emphasis on problems of grief post-traumatic stress disorder, and the experience of meaninglessness.
Input reconstruction of chaos sensors.
Yu, Dongchuan; Liu, Fang; Lai, Pik-Yin
2008-06-01
Although the sensitivity of sensors can be significantly enhanced using chaotic dynamics due to its extremely sensitive dependence on initial conditions and parameters, how to reconstruct the measured signal from the distorted sensor response becomes challenging. In this paper we suggest an effective method to reconstruct the measured signal from the distorted (chaotic) response of chaos sensors. This measurement signal reconstruction method applies the neural network techniques for system structure identification and therefore does not require the precise information of the sensor's dynamics. We discuss also how to improve the robustness of reconstruction. Some examples are presented to illustrate the measurement signal reconstruction method suggested.
Epiglottic reconstruction and subtotal laryngectomy.
Schechter, G L
1983-06-01
Vertical hemilaryngectomy has been expanded aggressively in recent years so that, in some cases, the term subtotal laryngectomy would be more appropriate. Reconstruction after these extended resections is a problem. Intraluminal stenting has not been successful in cases where resection has been aggressive. The resulting lumen is inadequate. As a means of overcoming this problem, the epiglottic reconstruction procedure has been promoted. This paper presents experiences with 12 patients who underwent epiglottic reconstruction after subtotal laryngectomy. Indications, anatomic details, and overall results using this reconstructive technique are outlined. It is the conclusion of the author that epiglottic reconstruction is an effective procedure for preservation of function after subtotal laryngectomy.
Scapholunate Ligament Reconstruction
Ross, Mark; Loveridge, Jeremy; Cutbush, Kenneth; Couzens, Greg
2013-01-01
Background Scapholunate reconstruction poses a challenge to orthopedic surgeons. Materials and Methods Prospective cohort. Description of Technique Our technique for scapholunate (SL) reconstruction involves ligament reconstruction utilizing a portion of the flexor carpi radialis tendon rerouted via transosseous tunnels across the scaphoid, lunate, and triquetrum (scapholunotriquetral tenodesis). The tendon graft is secured with interference screw fixation into the triquetrum. The philosophy of this new technique is to reduce subluxation and maintain the relationship between scaphoid and lunate by placing a graft through the center of the SL articulation. This graft is then tensioned by passing it centrally through the lunate and triquetrum and secured using an interference screw in the triquetrum. Secondary stabilizers, including the dorsal intercarpal ligament, are then augmented by passing the graft back to the scaphoid, crossing from the triquetrum over the proximal capitate. This further reinforces the translational relationship between the scaphoid and the triquetrum and, therefore, augments stability of the SL articulation. Results We have utilized this technique successfully in over 40 patients since 2009. We report on a prospective consecutive series of 11 patients with over 12 months follow-up (range 12 to 24 months) demonstrating good early radiological and clinical outcomes. Conclusions In developing this technique, we aimed to take the best features of previously described techniques and address the perceived shortcomings of each. We believe there are several benefits of our technique. Moreover, few other techniques address as many of the aspects of chronic SL instability as our technique does. PMID:24436802
Posteromedial Corner Reconstruction
Ferrer, Gonzalo; Leon, Agustín; Wirth, Hans; Mena, Adolfo; Tuca, María José; Espinoza, Gonzalo
2017-01-01
Objective: Report the experience, after 1-year follow-up, of 30 patients who underwent anatomical knee reconstruction of posteromedial corner (PMC) injuries, using La Prade´s Technique. Methods: Retrospective cohort study of 30 consecutive patients with PMC injuries operated between November 2010 and May 2014 by the same surgical team. Inclusion criteria: patients with clinical presentation and images (stress radiographs and MRI) compatible with PMC injury, who maintained a grade III chronic instability in spite of at least 3 months of orthopedic treatment, who were reconstructed using La Prade’s anatomical technique, and completed at least 12 months of follow-up. Exclusion criteria: discordance between clinical and image studies, grade I or II medial instability, and surgery performed through a different technique. Data was collected by reviewing the electronic files and images. Functional scores (IKDC and Lysholm) were applied and registered in the preoperative evaluation, and then 6 and 12 months after surgery. Results: Thirty patients (28 men and 2 women) met the inclusion criteria. Mean age was 43 years (24-69). The vast majority (28 patients) had a high-energy mechanism of injury. Twenty patients were diagnosed in the acute setting, while 10 had a delayed diagnosis after poor results of concomitant ligament reconstructions. With the exception of 2 patients, who presented with isolated PMC injury, the majority had associated injuries as detailed: 11 cases had PMC + anterior cruciate ligament (ACL) injury, 3 patients had PMC + posterior cruciate ligament (PCL) injury, 3 patients had PMC + meniscal tears, 9 patients had PMC + ACL + PCL injuries, and there were 2 cases of PMC + ACL + PCL + lateral collateral ligament injuries. Mean time for PMC reconstruction surgery was 5 months (range 2-32). Lysholm and IKDC scores were 18,2 (2-69) and 24,3 (9,2-52,9) respectively in the preoperative setting, improving to 76,7 (44-94) and 70,7 (36,8-95,4) after 1-year follow
The PandaRoot framework for simulation, reconstruction and analysis
NASA Astrophysics Data System (ADS)
Spataro, Stefano; PANDA Collaboration
2011-12-01
The PANDA experiment at the future facility FAIR will study anti-proton proton and anti-proton nucleus collisions in a beam momentum range from 2 GeV/c up to 15 GeV/c. The PandaRoot framework is part of the FairRoot project, a common software framework for the future FAIR experiments, and is currently used to simulate detector performances and to evaluate different detector concepts. It is based on the packages ROOT and Virtual MonteCarlo with Geant3 and Geant4. Different reconstruction algorithms for tracking and particle identification are under development and optimization, in order to achieve the performance requirements of the experiment. In the central tracker a first track fit is performed using a conformal map transformation based on a helix assumption, then the track is used as input for a Kalman Filter (package genfit), using GEANE as track follower. The track is then correlated to the pid detectors (e.g. Cerenkov detectors, EM Calorimeter or Muon Chambers) to evaluate a global particle identification probability, using a Bayesian approach or multivariate methods. Further implemented packages in PandaRoot are: the analysis tools framework Rho, the kinematic fitter package for vertex and mass constraint fits, and a fast simulation code based upon parametrized detector responses. PandaRoot was also tested on an Alien-based GRID infrastructure. The contribution will report about the status of PandaRoot and show some example results for analysis of physics benchmark channels.
Raw-data display and visual reconstruction validation in ALICE
NASA Astrophysics Data System (ADS)
Tadel, M.
2008-07-01
ALICE Event Visualization Environment (AliEVE) is based on ROOT and its GUI, 2D & 3D graphics classes. A small application kernel provides for registration and management of visualization objects. CINT scripts are used as an extensible mechanism for data extraction, selection and processing as well as for steering of frequent event-related tasks. AliEVE is used for event visualization in offline and high-level trigger frameworks. Mechanisms and base-classes provided for visual representation of raw-data for different detector-types are described. Common infrastructure for thresholding and color-coding of signal/time information, placement of detector-modules in various 2D/3D layouts and for user-interaction with displayed data is presented. Methods for visualization of raw-data on different levels of detail are discussed as they are expected to play an important role during early detector operation with poorly understood detector calibration, occupancy and noise-levels. Since September 2006 ALICE applies a regular visual-scanning procedure to simulated proton-proton data to detect any shortcomings in cluster finding, tracking and primary & secondary vertex reconstruction. A high-level of interactivity is required to allow in-depth exploration of event-structure. Navigation back to simulation records is supported for debugging purposes. Standard 2D projections and transformations are available for clusters, tracks and simplified detector geometry.
Reconstructing vanished ocean basins
NASA Astrophysics Data System (ADS)
Müller, D.; Sdrolias, M.; Gaina, C.
2006-05-01
The large-scale patterns of mantle convection are mainly dependent on the history of subduction. Therefore some of the primary constraints for subduction models are given by of the location of subduction zones through time, and of the convergence vectors and age of subducted lithosphere. This requires the complete reconstruction of ocean floor through time, including the main ocean basins, back-arc basins, and now subducted ocean crust, and tying these kinematic models to geodynamic simulations. We reconstruct paleo- oceans by creating "synthetic plates", the locations and geometry of which is established on the basis of preserved ocean crust (magnetic lineations and fracture zones), geological data, paleogeography, and the rules of plate tectonics. We use a merged moving hotspot (Late Cretaceous-present) and palaeomagnetic/fixed hotspot (Early Cretaceous) reference frame, coupled with reconstructed spreading histories of the Pacific, Phoenix and Farallon plates and the plates involved in the Tethys oceanic domain. Based on this approach we have created a set of global oceanic paleo-isochrons and paleo-oceanic age grids. The grids also provide the first complete global set of paleo-basement depth maps, including now subducted ocean floor, for the last 130 million years based on a depth-age relationship. We show that the mid-Cretaceous sealevel highstand was primarily caused by two main factors: (1) the "supercontinent breakup effect", which resulted in the creation of the mid-Atlantic and Indian Ocean ridges at the expense of subducting old ocean floor in the Tethys and (2) by a changing age-area distribution of Pacific ocean floor through time, resulting from the subduction of the Pacific-Izanagi, Pacific-Phoenix and Pacific-Farallon ridges. These grids provide model constraints for subduction dynamics through time and represent a framework for backtracking biogeographic and sediment data from ocean drilling and for constraining the opening/closing of oceanic
Ambjoern, J.; Jurkiewicz, J.; Loll, R.
2005-09-15
We provide detailed evidence for the claim that nonperturbative quantum gravity, defined through state sums of causal triangulated geometries, possesses a large-scale limit in which the dimension of spacetime is four and the dynamics of the volume of the universe behaves semiclassically. This is a first step in reconstructing the universe from a dynamical principle at the Planck scale, and at the same time provides a nontrivial consistency check of the method of causal dynamical triangulations. A closer look at the quantum geometry reveals a number of highly nonclassical aspects, including a dynamical reduction of spacetime to two dimensions on short scales and a fractal structure of slices of constant time.
Penile surgery and reconstruction.
Perovic, Sava V; Djordjevic, Miroslav L J; Kekic, Zoran K; Djakovic, Nenad G
2002-05-01
This review will highlight recent advances in the field of penile reconstructive surgery in the paediatric and adult population. It is based on the work published during the year 2001. Besides the anatomical and histological studies of the penis, major contributions have been described in congenital and acquired penile anomalies. Also, a few new techniques and modifications of old procedures are described in order to improve the final functional and aesthetic outcome. The techniques for penile enlargement present a trend in the new millennium, but are still at the stage of investigation.
Photometric Lunar Surface Reconstruction
NASA Technical Reports Server (NTRS)
Nefian, Ara V.; Alexandrov, Oleg; Morattlo, Zachary; Kim, Taemin; Beyer, Ross A.
2013-01-01
Accurate photometric reconstruction of the Lunar surface is important in the context of upcoming NASA robotic missions to the Moon and in giving a more accurate understanding of the Lunar soil composition. This paper describes a novel approach for joint estimation of Lunar albedo, camera exposure time, and photometric parameters that utilizes an accurate Lunar-Lambertian reflectance model and previously derived Lunar topography of the area visualized during the Apollo missions. The method introduced here is used in creating the largest Lunar albedo map (16% of the Lunar surface) at the resolution of 10 meters/pixel.
Evolutionary tree reconstruction
NASA Technical Reports Server (NTRS)
Cheeseman, Peter; Kanefsky, Bob
1990-01-01
It is described how Minimum Description Length (MDL) can be applied to the problem of DNA and protein evolutionary tree reconstruction. If there is a set of mutations that transform a common ancestor into a set of the known sequences, and this description is shorter than the information to encode the known sequences directly, then strong evidence for an evolutionary relationship has been found. A heuristic algorithm is described that searches for the simplest tree (smallest MDL) that finds close to optimal trees on the test data. Various ways of extending the MDL theory to more complex evolutionary relationships are discussed.
Reconstructing the Antikythera Mechanism
NASA Astrophysics Data System (ADS)
Freeth, Tony
The Antikythera Mechanism is a geared astronomical calculating machine from ancient Greece. The extraordinary nature of this device has become even more apparent in recent years as a result of research under the aegis of the Antikythera Mechanism Research Project (AMRP) - an international collaboration of scientists, historians, museum staff, engineers, and imaging specialists. Though many questions still remain, we may now be close to reconstructing the complete machine. As a technological artifact, it is unique in the ancient world. Its brilliant design conception means that it is a landmark in the history of science and technology.
NASA Technical Reports Server (NTRS)
Desai, Prasun N.; Qualls, Garry D.
2008-01-01
An overview of the reconstruction analyses performed for the Stardust capsule entry is described. The results indicate that the actual entry was very close to the pre-entry predictions. The capsule landed 8.1 km north-northwest of the desired target at Utah Test and Training Range. Analyses of infrared video footage and radar range data (obtained from tracking stations) during the descent show that drogue parachute deployment was 4.8 s later than the pre-entry prediction, while main parachute deployment was 19.3 s earlier than the pre-set timer indicating that main deployment was actually triggered by the backup baroswitch. Reconstruction of a best estimated trajectory revealed that the aerodynamic drag experienced by the capsule during hypersonic flight was within 1% of pre-entry predications. Observations of the heatshield support the pre-entry estimates of small hypersonic angles of attack, since there was very little, if any, charring of the shoulder region or the aftbody. Through this investigation, an overall assertion can be made that all the data gathered from the Stardust capsule entry were consistent with flight performance close to nominal pre-entry predictions. Consequently, the design principles and methodologies utilized for the flight dynamics, aerodynamics, and aerothermodynamics analyses have been corroborated.
Parallel ptychographic reconstruction
Nashed, Youssef S. G.; Vine, David J.; Peterka, Tom; Deng, Junjing; Ross, Rob; Jacobsen, Chris
2014-01-01
Ptychography is an imaging method whereby a coherent beam is scanned across an object, and an image is obtained by iterative phasing of the set of diffraction patterns. It is able to be used to image extended objects at a resolution limited by scattering strength of the object and detector geometry, rather than at an optics-imposed limit. As technical advances allow larger fields to be imaged, computational challenges arise for reconstructing the correspondingly larger data volumes, yet at the same time there is also a need to deliver reconstructed images immediately so that one can evaluate the next steps to take in an experiment. Here we present a parallel method for real-time ptychographic phase retrieval. It uses a hybrid parallel strategy to divide the computation between multiple graphics processing units (GPUs) and then employs novel techniques to merge sub-datasets into a single complex phase and amplitude image. Results are shown on a simulated specimen and a real dataset from an X-ray experiment conducted at a synchrotron light source. PMID:25607174
Biomaterials for craniofacial reconstruction
Neumann, Andreas; Kevenhoerster, Kevin
2011-01-01
Biomaterials for reconstruction of bony defects of the skull comprise of osteosynthetic materials applied after osteotomies or traumatic fractures and materials to fill bony defects which result from malformation, trauma or tumor resections. Other applications concern functional augmentations for dental implants or aesthetic augmentations in the facial region. For ostheosynthesis, mini- and microplates made from titanium alloys provide major advantages concerning biocompatibility, stability and individual fitting to the implant bed. The necessity of removing asymptomatic plates and screws after fracture healing is still a controversial issue. Risks and costs of secondary surgery for removal face a low rate of complications (due to corrosion products) when the material remains in situ. Resorbable osteosynthesis systems have similar mechanical stability and are especially useful in the growing skull. The huge variety of biomaterials for the reconstruction of bony defects makes it difficult to decide which material is adequate for which indication and for which site. The optimal biomaterial that meets every requirement (e.g. biocompatibility, stability, intraoperative fitting, product safety, low costs etc.) does not exist. The different material types are (autogenic) bone and many alloplastics such as metals (mainly titanium), ceramics, plastics and composites. Future developments aim to improve physical and biological properties, especially regarding surface interactions. To date, tissue engineered bone is far from routine clinical application. PMID:22073101
Unfavourable results in thumb reconstruction
Kumta, Samir M.
2013-01-01
The history of thumb reconstruction parallels the history of hand surgery. The attributes that make the thumb unique, and that the reconstructive surgeon must assess and try to restore when reconstructing a thumb, are: Position, stability, strength, length, motion, sensibility and appearance. Deficiency in any of these attributes can reduce the utility of the reconstructed thumb. A detailed assessment of the patient and his requirements needs to be performed before embarking on a thumb reconstruction. Most unsatisfactory results can be attributed to wrong choice of procedure. Component defects of the thumb are commonly treated by tissue from adjacent fingers, hand or forearm. With refinements in microsurgery, the foot has become a major source of tissue for component replacement in the thumb. Bone lengthening, osteoplastic reconstruction, pollicisation, and toe to hand transfers are the commonest methods of thumb reconstruction. Unfavourable results can be classified as functional and aesthetic. Some are common to all types of procedures. However each type of reconstruction has its own unique set of problems. Meticulous planning and execution is essential to give an aesthetic and functionally useful thumb. Secondary surgeries like tendon transfers, bone grafting, debulking, arthrodesis, may be required to correct deficiencies in the reconstruction. Attention needs to be paid to the donor site as well. PMID:24501466
Exercises in PET Image Reconstruction
NASA Astrophysics Data System (ADS)
Nix, Oliver
These exercises are complementary to the theoretical lectures about positron emission tomography (PET) image reconstruction. They aim at providing some hands on experience in PET image reconstruction and focus on demonstrating the different data preprocessing steps and reconstruction algorithms needed to obtain high quality PET images. Normalisation, geometric-, attenuation- and scatter correction are introduced. To explain the necessity of those some basics about PET scanner hardware, data acquisition and organisation are reviewed. During the course the students use a software application based on the STIR (software for tomographic image reconstruction) library 1,2 which allows them to dynamically select or deselect corrections and reconstruction methods as well as to modify their most important parameters. Following the guided tutorial, the students get an impression on the effect the individual data precorrections have on image quality and what happens if they are forgotten. Several data sets in sinogram format are provided, such as line source data, Jaszczak phantom data sets with high and low statistics and NEMA whole body phantom data. The two most frequently used reconstruction algorithms in PET image reconstruction, filtered back projection (FBP) and the iterative OSEM (ordered subset expectation maximation) approach are used to reconstruct images. The exercise should help the students gaining an understanding what the reasons for inferior image quality and artefacts are and how to improve quality by a clever choice of reconstruction parameters.
NASA Astrophysics Data System (ADS)
Gómez-Rocha, M.; Hilger, T.; Krassnigg, A.
2016-04-01
We extend earlier investigations of heavy-light pseudoscalar mesons to the vector case, using a simple model in the context of the Dyson-Schwinger-Bethe-Salpeter approach. We investigate the effects of a dressed quark-gluon vertex in a systematic fashion and illustrate and attempt to quantify corrections beyond the phenomenologically very useful and successful rainbow-ladder truncation. In particular we investigate the dressed quark-photon vertex in such a setup and make a prediction for the experimentally as yet unknown mass of the Bc* , which we obtain at 6.334 GeV well in line with predictions from other approaches. Furthermore, we combine a comprehensive set of results from the theoretical literature. The theoretical average for the mass of the Bc* meson is 6.336 ±0.002 GeV .
Power and area efficient 4-bit column-level ADC in a CMOS pixel sensor for the ILD vertex detector
NASA Astrophysics Data System (ADS)
Zhang, L.; Morel, F.; Hu-Guo, Ch; Hu, Y.
2013-01-01
A 48 × 64 pixels prototype CMOS pixel sensor (CPS) integrated with 4-bit column-level, self triggered ADCs for the outer layers of the ILD vertex detector (VTX) was developed and fabricated in a 0.35 μm CMOS process with a pixel pitch of 35 μm. The pixel concept combines in-pixel amplification with a correlated double sampling (CDS) operation. The ADCs accommodating the pixel read out in a rolling shutter mode complete the conversion by performing a multi-bit/step approximation. The design was optimised for power saving at sampling frequency. The prototype sensor is currently at the stage of being started testing and evaluation. So what is described is based on post simulation results rather than test data. This 4-bit ADC dissipates, at a 3-V supply and 6.25-MS/s sampling rate, 486 μW in its inactive mode, which is by far the most frequent. This value rises to 714 μW in case of the active mode. Its footprint amounts to 35 × 545 μm2.
G W -BSE, self-consistency, and vertex corrections applied to group IB/IIB atoms and oxide molecules
NASA Astrophysics Data System (ADS)
Hung, Linda; Ogut, Serdar
2015-03-01
Time-dependent density functional theory (TDDFT), the GW approximation, and the Bethe-Salpeter equation (BSE) are often used for the first-principles calculation of excited-state properties of materials that contain transition metals. Accuracy is improved compared to mean-field theories such as Kohn-Sham DFT or Hartree-Fock; however, predicted quasiparticle levels and optical spectra can still differ from experiment. We model Cu, Zn, Ag, and Cd atoms and their oxide molecules to assess various approximations in many-body perturbation theory methods that contribute to these differences. In particular, we examine how self-consistent iterations and/or a two-point vertex function affect the predicted excitation energies, compared to ``one-shot'' G0W0 calculations. Experimental measurements of optical spectra and ionization energies for charged and neutral atoms are widely available, and allow us to evaluate excitations from both s and d states. Differences between TDDFT and BSE spectra are also discussed. Calculations are performed with RGWBS, a software suite which uses a basis of transition space and quasiparticle wavefunctions. Supported by DOE Grant No. DE-SC0001853.
Buzatu, Adrian; /McGill U.
2006-08-01
Improving our ability to identify the top quark pair (t{bar t}) primary vertex (PV) on an event-by-event basis is essential for many analyses in the lepton-plus-jets channel performed by the Collider Detector at Fermilab (CDF) Collaboration. We compare the algorithm currently used by CDF (A1) with another algorithm (A2) using Monte Carlo simulation at high instantaneous luminosities. We confirm that A1 is more efficient than A2 at selecting the t{bar t} PV at all PV multiplicities, both with efficiencies larger than 99%. Event selection rejects events with a distance larger than 5 cm along the proton beam between the t{bar t} PV and the charged lepton. We find flat distributions for the signal over background significance of this cut for all cut values larger than 1 cm, for all PV multiplicities and for both algorithms. We conclude that any cut value larger than 1 cm is acceptable for both algorithms under the Tevatron's expected instantaneous luminosity improvements.
A Full Multi-Grid Method for the Solution of the Cell Vertex Finite Volume Cauchy-Riemann Equations
NASA Technical Reports Server (NTRS)
Borzi, A.; Morton, K. W.; Sueli, E.; Vanmaele, M.
1996-01-01
The system of inhomogeneous Cauchy-Riemann equations defined on a square domain and subject to Dirichlet boundary conditions is considered. This problem is discretised by using the cell vertex finite volume method on quadrilateral meshes. The resulting algebraic problem is overdetermined and the solution is defined in a least squares sense. By this approach a consistent algebraic problem is obtained which differs from the original one by O(h(exp 2)) perturbations of the right-hand side. A suitable cell-based convergent smoothing iteration is presented which is naturally linked to the least squares formulation. Hence, a standard multi-grid algorithm is reported which combines the given smoother and cell-based transfer operators. Some remarkable reduction properties of these operators are shown. A full multi-grid method is discussed which solves the discrete problem to the level of truncation error by employing one multi-grid cycle at each current level of discretisation. Experiments and applications of the full multi-grid scheme are presented.
NASA Astrophysics Data System (ADS)
Moortgat, Joachim; Firoozabadi, Abbas
2016-06-01
Problems of interest in hydrogeology and hydrocarbon resources involve complex heterogeneous geological formations. Such domains are most accurately represented in reservoir simulations by unstructured computational grids. Finite element methods accurately describe flow on unstructured meshes with complex geometries, and their flexible formulation allows implementation on different grid types. In this work, we consider for the first time the challenging problem of fully compositional three-phase flow in 3D unstructured grids, discretized by any combination of tetrahedra, prisms, and hexahedra. We employ a mass conserving mixed hybrid finite element (MHFE) method to solve for the pressure and flux fields. The transport equations are approximated with a higher-order vertex-based discontinuous Galerkin (DG) discretization. We show that this approach outperforms a face-based implementation of the same polynomial order. These methods are well suited for heterogeneous and fractured reservoirs, because they provide globally continuous pressure and flux fields, while allowing for sharp discontinuities in compositions and saturations. The higher-order accuracy improves the modeling of strongly non-linear flow, such as gravitational and viscous fingering. We review the literature on unstructured reservoir simulation models, and present many examples that consider gravity depletion, water flooding, and gas injection in oil saturated reservoirs. We study convergence rates, mesh sensitivity, and demonstrate the wide applicability of our chosen finite element methods for challenging multiphase flow problems in geometrically complex subsurface media.
Nagoor Gani, A; Latha, S R
2016-01-01
A Hamiltonian cycle in a graph is a cycle that visits each node/vertex exactly once. A graph containing a Hamiltonian cycle is called a Hamiltonian graph. There have been several researches to find the number of Hamiltonian cycles of a Hamilton graph. As the number of vertices and edges grow, it becomes very difficult to keep track of all the different ways through which the vertices are connected. Hence, analysis of large graphs can be efficiently done with the assistance of a computer system that interprets graphs as matrices. And, of course, a good and well written algorithm will expedite the analysis even faster. The most convenient way to quickly test whether there is an edge between two vertices is to represent graphs using adjacent matrices. In this paper, a new algorithm is proposed to find fuzzy Hamiltonian cycle using adjacency matrix and the degree of the vertices of a fuzzy graph. A fuzzy graph structure is also modeled to illustrate the proposed algorithms with the selected air network of Indigo airlines.
Towards a high performance vertex detector based on 3D integration of deep N-well MAPS
NASA Astrophysics Data System (ADS)
Re, V.
2010-06-01
The development of deep N-Well (DNW) CMOS active pixel sensors was driven by the ambitious goal of designing a monolithic device with similar functionalities as in hybrid pixel readout chips, such as pixel-level sparsification and time stamping. The implementation of the DNW MAPS concept in a 3D vertical integration process naturally leads the designer towards putting more intelligence in the chip and in the pixels themselves, achieving novel device structures based on the interconnection of two or more layers fabricated in the same technology. These devices are read out with a data-push scheme that makes it possible to use pixel data for the generation of a flexible level 1 track trigger, based on associative memories, with short latency and high efficiency. This paper gives an update of the present status of DNW MAPS design in both 2D and 3D versions, and presents a discussion of the architectures that are being devised for the Layer 0 of the SuperB Silicon Vertex Tracker.
NASA Astrophysics Data System (ADS)
Ramírez-Zavaleta, F.; Tavares-Velasco, G.; Toscano, J. J.
2007-04-01
In a recent paper [J. Montano, F. Ramírez-Zavaleta, G. Tavares-Velasco, and J. J. Toscano, Phys. Rev. D 72, 055023 (2005).PRVDAQ0556-282110.1103/PhysRevD.72.055023], we investigated the effects of the massive charged gauge bosons (bileptons) predicted by the minimal 331 model on the off-shell vertex WWV* (V=γ, Z) using a SUL(2)×UY(1) covariant gauge-fixing term for the bileptons. We proceed along the same lines and calculate the effects of the gauge bosons predicted by the 331 model with right-handed neutrinos. It is found that the bilepton effects on the WWV* vertex are of the same order of magnitude as those arising from the standard model and several of its extensions, provided that the bilepton mass is of the order of a few hundred of GeVs. For heavier bileptons, their effects on the WWV* vertex are negligible. The behavior of the form factors at high energies is also discussed as it is a reflection of the gauge invariance and gauge independence of the WWV* Green function obtained via our quantization method.
Kizilersue, Ayse; Pennington, Michael R.
2009-06-15
In principle, calculation of a full Green's function in any field theory requires knowledge of the infinite set of multipoint Green's functions, unless one can find some way of truncating the corresponding Schwinger-Dyson equations. For the fermion and boson propagators in QED this requires an ansatz for the full 3-point vertex. Here we illustrate how the properties of gauge invariance, gauge covariance and multiplicative renormalizability impose severe constraints on this fermion-boson interaction, allowing a consistent truncation of the propagator equations. We demonstrate how these conditions imply that the 3-point vertex in the propagator equations is largely determined by the behavior of the fermion propagator itself and not by knowledge of the many higher-point functions. We give an explicit form for the fermion-photon vertex, which in the fermion and photon propagator fulfills these constraints to all orders in leading logarithms for massless QED, and accords with the weak coupling limit in perturbation theory at O({alpha}). This provides the first attempt to deduce nonperturbative Feynman rules for strong physics calculations of propagators in massless QED that ensure a more consistent truncation of the 2-point Schwinger-Dyson equations. The generalization to next-to-leading order and masses will be described in a longer publication.
Etalon Array Reconstructive Spectrometry
NASA Astrophysics Data System (ADS)
Huang, Eric; Ma, Qian; Liu, Zhaowei
2017-01-01
Compact spectrometers are crucial in areas where size and weight may need to be minimized. These types of spectrometers often contain no moving parts, which makes for an instrument that can be highly durable. With the recent proliferation in low-cost and high-resolution cameras, camera-based spectrometry methods have the potential to make portable spectrometers small, ubiquitous, and cheap. Here, we demonstrate a novel method for compact spectrometry that uses an array of etalons to perform spectral encoding, and uses a reconstruction algorithm to recover the incident spectrum. This spectrometer has the unique capability for both high resolution and a large working bandwidth without sacrificing sensitivity, and we anticipate that its simplicity makes it an excellent candidate whenever a compact, robust, and flexible spectrometry solution is needed.
Etalon Array Reconstructive Spectrometry
Huang, Eric; Ma, Qian; Liu, Zhaowei
2017-01-01
Compact spectrometers are crucial in areas where size and weight may need to be minimized. These types of spectrometers often contain no moving parts, which makes for an instrument that can be highly durable. With the recent proliferation in low-cost and high-resolution cameras, camera-based spectrometry methods have the potential to make portable spectrometers small, ubiquitous, and cheap. Here, we demonstrate a novel method for compact spectrometry that uses an array of etalons to perform spectral encoding, and uses a reconstruction algorithm to recover the incident spectrum. This spectrometer has the unique capability for both high resolution and a large working bandwidth without sacrificing sensitivity, and we anticipate that its simplicity makes it an excellent candidate whenever a compact, robust, and flexible spectrometry solution is needed. PMID:28074883
Biomatrices for bladder reconstruction.
Lin, Hsueh-Kung; Madihally, Sundar V; Palmer, Blake; Frimberger, Dominic; Fung, Kar-Ming; Kropp, Bradley P
2015-03-01
There is a demand for tissue engineering of the bladder needed by patients who experience a neurogenic bladder or idiopathic detrusor overactivity. To avoid complications from augmentation cystoplasty, the field of tissue engineering seeks optimal scaffolds for bladder reconstruction. Naturally derived biomaterials as well as synthetic and natural polymers have been explored as bladder substitutes. To improve regenerative properties, these biomaterials have been conjugated with functional molecules, combined with nanotechology, or seeded with exogenous cells. Although most studies reported complete and functional bladder regeneration in small-animal models, results from large-animal models and human clinical trials varied. For functional bladder regeneration, procedures for biomaterial fabrication, incorporation of biologically active agents, introduction of nanotechnology, and application of stem-cell technology need to be standardized. Advanced molecular and medical technologies such as next generation sequencing and magnetic resonance imaging can be introduced for mechanistic understanding and non-invasive monitoring of regeneration processes, respectively.
Metrological digital audio reconstruction
Fadeyev; Vitaliy , Haber; Carl
2004-02-19
Audio information stored in the undulations of grooves in a medium such as a phonograph record may be reconstructed, with little or no contact, by measuring the groove shape using precision metrology methods coupled with digital image processing and numerical analysis. The effects of damage, wear, and contamination may be compensated, in many cases, through image processing and analysis methods. The speed and data handling capacity of available computing hardware make this approach practical. Two examples used a general purpose optical metrology system to study a 50 year old 78 r.p.m. phonograph record and a commercial confocal scanning probe to study a 1920's celluloid Edison cylinder. Comparisons are presented with stylus playback of the samples and with a digitally re-mastered version of an original magnetic recording. There is also a more extensive implementation of this approach, with dedicated hardware and software.
Reconstruction Using Witness Complexes
Oudot, Steve Y.
2010-01-01
We present a novel reconstruction algorithm that, given an input point set sampled from an object S, builds a one-parameter family of complexes that approximate S at different scales. At a high level, our method is very similar in spirit to Chew’s surface meshing algorithm, with one notable difference though: the restricted Delaunay triangulation is replaced by the witness complex, which makes our algorithm applicable in any metric space. To prove its correctness on curves and surfaces, we highlight the relationship between the witness complex and the restricted Delaunay triangulation in 2d and in 3d. Specifically, we prove that both complexes are equal in 2d and closely related in 3d, under some mild sampling assumptions. PMID:21643440
Reconstructability analysis of epistasis.
Zwick, Martin
2011-01-01
The literature on epistasis describes various methods to detect epistatic interactions and to classify different types of epistasis. Reconstructability analysis (RA) has recently been used to detect epistasis in genomic data. This paper shows that RA offers a classification of types of epistasis at three levels of resolution (variable-based models without loops, variable-based models with loops, state-based models). These types can be defined by the simplest RA structures that model the data without information loss; a more detailed classification can be defined by the information content of multiple candidate structures. The RA classification can be augmented with structures from related graphical modeling approaches. RA can analyze epistatic interactions involving an arbitrary number of genes or SNPs and constitutes a flexible and effective methodology for genomic analysis.
Reconstructing the Alcatraz escape
NASA Astrophysics Data System (ADS)
Baart, F.; Hoes, O.; Hut, R.; Donchyts, G.; van Leeuwen, E.
2014-12-01
In the night of June 12, 1962 three inmates used a raft made of raincoatsto escaped the ultimate maximum security prison island Alcatraz in SanFrancisco, United States. History is unclear about what happened tothe escapees. At what time did they step into the water, did theysurvive, if so, where did they reach land? The fate of the escapees has been the subject of much debate: did theymake landfall on Angel Island, or did the current sweep them out ofthe bay and into the cold pacific ocean? In this presentation, we try to shed light on this historic case using avisualization of a high-resolution hydrodynamic simulation of the San Francisco Bay, combined with historical tidal records. By reconstructing the hydrodynamic conditions and using a particle based simulation of the escapees we show possible scenarios. The interactive model is visualized using both a 3D photorealistic and web based visualization. The "Escape from Alcatraz" scenario demonstrates the capabilities of the 3Di platform. This platform is normally used for overland flooding (1D/2D). The model engine uses a quad tree structure, resulting in an order of magnitude speedup. The subgrid approach takes detailed bathymetry information into account. The inter-model variability is tested by comparing the results with the DFlow Flexible Mesh (DFlowFM) San Francisco Bay model. Interactivity is implemented by converting the models from static programs to interactive libraries, adhering to the Basic ModelInterface (BMI). Interactive models are more suitable for answeringexploratory research questions such as this reconstruction effort. Although these hydrodynamic simulations only provide circumstantialevidence for solving the mystery of what happened during the foggy darknight of June 12, 1962, it can be used as a guidance and provides aninteresting testcase to apply interactive modelling.
An update on penile reconstruction
Garaffa, Giulio; Raheem, Amr Abdel; Ralph, David John
2011-01-01
Penile reconstruction still represents a formidable challenge for the urologist. In this review, the most recent advances in penile reconstruction after trauma, excision of benign and malignant disease and in patients with micropenis, aphallia or female to male gender dysphoria are reported. PMID:21540867
[Graphic reconstruction of anatomic surfaces].
Ciobanu, O
2004-01-01
The paper deals with the graphic reconstruction of anatomic surfaces in a virtual 3D setting. Scanning technologies and soft provides a greater flexibility in the digitization of surfaces and a higher resolution and accuracy. An alternative cheap method for the reconstruction of 3D anatomic surfaces is presented in connection with some studies and international projects developed by Medical Design research team.
Convex Accelerated Maximum Entropy Reconstruction
Worley, Bradley
2016-01-01
Maximum entropy (MaxEnt) spectral reconstruction methods provide a powerful framework for spectral estimation of nonuniformly sampled datasets. Many methods exist within this framework, usually defined based on the magnitude of a Lagrange multiplier in the MaxEnt objective function. An algorithm is presented here that utilizes accelerated first-order convex optimization techniques to rapidly and reliably reconstruct nonuniformly sampled NMR datasets using the principle of maximum entropy. This algorithm – called CAMERA for Convex Accelerated Maximum Entropy Reconstruction Algorithm – is a new approach to spectral reconstruction that exhibits fast, tunable convergence in both constant-aim and constant-lambda modes. A high-performance, open source NMR data processing tool is described that implements CAMERA, and brief comparisons to existing reconstruction methods are made on several example spectra. PMID:26894476
Reconstructing pedigrees: a combinatorial perspective.
Steel, Mike; Hein, Jotun
2006-06-07
A pedigree is a directed graph that displays the relationship between individuals according to their parentage. We derive a combinatorial result that shows how any pedigree-up to individuals who have no extant (present-day) ancestors-can be reconstructed from (sex-labelled) pedigrees that describe the ancestry of single extant individuals and pairs of extant individuals. Furthermore, this reconstruction can be done in polynomial time. We also provide an example to show that the corresponding reconstruction result does not hold for pedigrees that are not sex-labelled. We then show how any pedigree can also be reconstructed from two functions that just describe certain circuits in the pedigree. Finally, we obtain an enumeration result for pedigrees that is relevant to the question of how many segregating sites are needed to reconstruct pedigrees.
Revision Anterior Cruciate Ligament Reconstruction
Wilde, Jeffrey; Bedi, Asheesh; Altchek, David W.
2014-01-01
Context: Reconstruction of the anterior cruciate ligament (ACL) is one of the most common surgical procedures, with more than 200,000 ACL tears occurring annually. Although primary ACL reconstruction is a successful operation, success rates still range from 75% to 97%. Consequently, several thousand revision ACL reconstructions are performed annually and are unfortunately associated with inferior clinical outcomes when compared with primary reconstructions. Evidence Acquisition: Data were obtained from peer-reviewed literature through a search of the PubMed database (1988-2013) as well as from textbook chapters and surgical technique papers. Study Design: Clinical review. Level of Evidence: Level 4. Results: The clinical outcomes after revision ACL reconstruction are largely based on level IV case series. Much of the existing literature is heterogenous with regard to patient populations, primary and revision surgical techniques, concomitant ligamentous injuries, and additional procedures performed at the time of the revision, which limits generalizability. Nevertheless, there is a general consensus that the outcomes for revision ACL reconstruction are inferior to primary reconstruction. Conclusion: Excellent results can be achieved with regard to graft stability, return to play, and functional knee instability but are generally inferior to primary ACL reconstruction. A staged approach with autograft reconstruction is recommended in any circumstance in which a single-stage approach results in suboptimal graft selection, tunnel position, graft fixation, or biological milieu for tendon-bone healing. Strength-of-Recommendation Taxonomy (SORT): Good results may still be achieved with regard to graft stability, return to play, and functional knee instability, but results are generally inferior to primary ACL reconstruction: Level B. PMID:25364483
Cadaveric Scapholunate Reconstruction Using the Ligament Augmentation and Reconstruction System
Eng, Kevin; Wagels, Michael; Tham, Stephen K.
2014-01-01
Background Untreated scapholunate ligament disruption may lead to progressive wrist arthritis. Current techniques used to treat the disruption may not prevent arthritis because of attenuation of a reconstructive ligament substitute or failure to re-establish normal wrist kinematics. Questions/Purposes This study evaluates a combined synthetic-autologous technique for the treatment of scapholunate dissociation. Methods Scapholunate dissociation was created in six cadaveric wrists. The dorsal and volar components of the scapholunate ligament were reconstructed using the Ligament Augmentation & Reconstruction System (LARS; LARS, Arc-sur-Tille, France) and a modified Blatt capsulodesis performed. Reconstructed wrists were subjected to cyclic passive motion. Outcomes were measured radiologically and compared using Student's t-test. Results Carpal alignment was re-established following scapholunate ligament reconstruction. Carpal alignment was maintained after cyclic loading. Conclusions The technique described corrected the carpal malalignment associated with scapholunate dissociation. Corrected positions were maintained after one thousand cycles of flexion and extension without fraying or loosening of the LARS. Clinical Relevance Current popular techniques for scapholunate reconstruction do not address the important dorsal and palmar components of the ligament that control their intercarpal motion. Reconstruction of the dorsal and palmar components of the scapholunate ligament can be achieved through a dorsal approach to the wrist. PMID:25097813
Porcelain three-dimensional shape reconstruction and its color reconstruction
NASA Astrophysics Data System (ADS)
Yu, Xiaoyang; Wu, Haibin; Yang, Xue; Yu, Shuang; Wang, Beiyi; Chen, Deyun
2013-01-01
In this paper, structured light three-dimensional measurement technology was used to reconstruct the porcelain shape, and further more the porcelain color was reconstructed. So the accurate reconstruction of the shape and color of porcelain was realized. Our shape measurement installation drawing is given. Because the porcelain surface is color complex and highly reflective, the binary Gray code encoding is used to reduce the influence of the porcelain surface. The color camera was employed to obtain the color of the porcelain surface. Then, the comprehensive reconstruction of the shape and color was realized in Java3D runtime environment. In the reconstruction process, the space point by point coloration method is proposed and achieved. Our coloration method ensures the pixel corresponding accuracy in both of shape and color aspects. The porcelain surface shape and color reconstruction experimental results completed by proposed method and our installation, show that: the depth range is 860 ˜ 980mm, the relative error of the shape measurement is less than 0.1%, the reconstructed color of the porcelain surface is real, refined and subtle, and has the same visual effect as the measured surface.
Reconstruction after internal hemipelvectomy: outcomes and reconstructive algorithm.
Chao, Albert H; Neimanis, Sara A; Chang, David W; Lewis, Valerae O; Hanasono, Matthew M
2015-03-01
Internal hemipelvectomy may be indicated in the treatment of select tumors of the pelvis and lower extremity, and has become our preferred approach due to favorable outcomes. After such extensive resections, which can involve long operative times and significant blood loss, there are often substantial bony and soft tissue deficits. However, it is unclear whether the benefits of reconstruction in these cases outweigh the risks involved. In the largest series to date of internal hemipelvectomy patients, we evaluate the effect of reconstruction on surgical complications, postoperative function, and survival. A retrospective review was performed of all patients who underwent internal hemipelvectomy between 1998 and 2011. Outcomes for patients who underwent reconstruction were compared to outcomes for those who did not. A total of 111 patients underwent internal hemipelvectomy, of which 51 (45.9%) received reconstruction and 60 (54.1%) did not. In cases of reconstruction, 30 (58.8%) involved placement of mesh for abdominal wall and pelvic floor reconstruction, 27 (52.9%) involved a soft tissue flap, and 15 (29.4%) involved a vascularized bone flap to restore pelvic ring continuity. Two concurrent reconstructive procedures were performed in 22 (43.1%) patients. The overall rate of early complications was 19.8%, which occurred in 15.7% of patients who received reconstruction compared to 23.3% in patients who did not (P = 0.35). Late recipient-site complications occurred significantly less often in patients who underwent reconstruction (7.8% vs 26.7%, respectively; P = 0.01). From a functional standpoint, Musculoskeletal Tumor Society scores were higher in patients who underwent reconstruction, although this was not statistically significant (62.8% vs 48.4%, respectively; P = 0.12). The 2 groups were similar with regard to operative time, blood loss, and hospital stay, as well as overall and disease-free survival rates. Overall, these results indicate that immediate
Faber, Vance; Moore, James W.
1992-01-01
A network of interconnected processors is formed from a vertex symmetric graph selected from graphs .GAMMA..sub.d (k) with degree d, diameter k, and (d+1)!/(d-k+1)! processors for each d.gtoreq.k and .GAMMA..sub.d (k,-1) with degree 3-1, diameter k+1, and (d+1)!/(d-k+1)! processors for each d.gtoreq.k.gtoreq.4. Each processor has an address formed by one of the permutations from a predetermined sequence of letters chosen a selected number of letters at a time, and an extended address formed by appending to the address the remaining ones of the predetermined sequence of letters. A plurality of transmission channels is provided from each of the processors, where each processor has one less channel than the selected number of letters forming the sequence. Where a network .GAMMA..sub.d (k,-1) is provided, no processor has a channel connected to form an edge in a direction .delta..sub.1. Each of the channels has an identification number selected from the sequence of letters and connected from a first processor having a first extended address to a second processor having a second address formed from a second extended address defined by moving to the front of the first extended address the letter found in the position within the first extended address defined by the channel identification number. The second address is then formed by selecting the first elements of the second extended address corresponding to the selected number used to form the address permutations.
Lu Yuanming; Wang Ziqiang; Wen Xiaogang; Wang Zhenghan
2010-03-15
In the pattern-of-zeros approach to quantum Hall states, a set of data (n;m;S{sub a}|a=1,...,n;n,m,S{sub a} is n element of N) (called the pattern of zeros) is introduced to characterize a quantum Hall wave function. In this paper we find sufficient conditions on the pattern of zeros so that the data correspond to a valid wave function. Some times, a set of data (n;m;S{sub a}) corresponds to a unique quantum Hall state, while other times, a set of data corresponds to several different quantum Hall states. So in the latter cases, the pattern of zeros alone does not completely characterize the quantum Hall states. In this paper, we find that the following expanded set of data (n;m;S{sub a};c|a=1,...,n;n,m,S{sub a} is an element of N;c is an element of R) provides a more complete characterization of quantum Hall states. Each expanded set of data completely characterizes a unique quantum Hall state, at least for the examples discussed in this paper. The result is obtained by combining the pattern of zeros and Z{sub n} simple-current vertex algebra which describes a large class of Abelian and non-Abelian quantum Hall states PHI{sub Z{sub n}{sup sc}}. The more complete characterization in terms of (n;m;S{sub a};c) allows us to obtain more topological properties of those states, which include the central charge c of edge states, the scaling dimensions and the statistics of quasiparticle excitations.
2015-01-01
Background Cellular processes are known to be modular and are realized by groups of proteins implicated in common biological functions. Such groups of proteins are called functional modules, and many community detection methods have been devised for their discovery from protein interaction networks (PINs) data. In current agglomerative clustering approaches, vertices with just a very few neighbors are often classified as separate clusters, which does not make sense biologically. Also, a major limitation of agglomerative techniques is that their computational efficiency do not scale well to large PINs. Finally, PIN data obtained from large scale experiments generally contain many false positives, and this makes it hard for agglomerative clustering methods to find the correct clusters, since they are known to be sensitive to noisy data. Results We propose a local similarity premetric, the relative vertex clustering value, as a new criterion allowing to decide when a node can be added to a given node's cluster and which addresses the above three issues. Based on this criterion, we introduce a novel and very fast agglomerative clustering technique, FAC-PIN, for discovering functional modules and protein complexes from a PIN data. Conclusions Our proposed FAC-PIN algorithm is applied to nine PIN data from eight different species including the yeast PIN, and the identified functional modules are validated using Gene Ontology (GO) annotations from DAVID Bioinformatics Resources. Identified protein complexes are also validated using experimentally verified complexes. Computational results show that FAC-PIN can discover functional modules or protein complexes from PINs more accurately and more efficiently than HC-PIN and CNM, the current state-of-the-art approaches for clustering PINs in an agglomerative manner. PMID:25734691
Karmanov, V. A.; Smirnov, A. V.; Mathiot, J.-F.
2007-02-15
In light-front dynamics, the regularization of amplitudes by traditional cutoffs imposed on the transverse and longitudinal components of particle momenta corresponds to restricting the integration volume by a nonrotationally invariant domain. The result depends not only on the size of this domain (i.e., on the cutoff values), but also on its orientation determined by the position of the light-front plane. Explicitly covariant formulation of light-front dynamics allows us to parametrize the latter dependence in a very transparent form. If we decompose the regularized amplitude in terms of independent invariant amplitudes, extra (nonphysical) terms should appear, with spin structures which explicitly depend on the orientation of the light-front plane. The number of form factors, i.e., the coefficients of this decomposition, therefore also increases. The spin-1/2 fermion self-energy is determined by three scalar functions, instead of the two standard ones, while for the elastic electromagnetic vertex the number of form factors increases from two to five. In the present paper we calculate perturbatively all these form factors in the Yukawa model. Then we compare the results obtained in the two following ways: (i) by using the light-front dynamics graph technique rules directly; (ii) by integrating the corresponding Feynman amplitudes in terms of the light-front variables. For each of these methods, we use two types of regularization: the transverse and longitudinal cutoffs, and the Pauli-Villars regularization. In the latter case, the dependence of amplitudes on the light-front plane orientation vanishes completely provided enough Pauli-Villars subtractions are made.
Ulnar Collateral Ligament Reconstruction
Erickson, Brandon J.; Harris, Joshua D.; Chalmers, Peter N.; Bach, Bernard R.; Verma, Nikhil N.; Bush-Joseph, Charles A.; Romeo, Anthony A.
2015-01-01
Context: Ulnar collateral ligament (UCL) injuries lead to pain and loss of performance in the thrower’s elbow. Ulnar collateral ligament reconstruction (UCLR) is a reliable treatment option for the symptomatic, deficient UCL. Injury to the UCL usually occurs because of chronic accumulation of microtrauma, although acute ruptures occur and an acute-on-chronic presentation is also common. Evidence Acquisition: Computerized databases, references from pertinent articles, and research institutions were searched for all studies using the search terms ulnar collateral ligament from 1970 until 2015. Study Design: Clinical review. Level of Evidence: Level 5. Results: All studies reporting outcomes for UCLR are level 4. Most modern fixation methodologies appear to be biomechanically and clinically equivalent. Viable graft choices include ipsilateral palmaris longus tendon autograft, gracilis or semitendinosus autograft, and allograft. Clinical studies report excellent outcomes of UCLR for both recreational and elite level athletes with regard to return to sport and postoperative performance. Complications, although rare, include graft rerupture or attenuation, ulnar nerve symptoms, stiffness, pain, and/or weakness leading to decreased performance. Conclusion: Injuries to the UCL have become commonplace among pitchers. Nonoperative treatment should be attempted, but the limited studies have not shown promising results. Operative treatment can be performed with several techniques, with retrospective studies showing promising results. Complications include ulnar neuropathy as well as failure to return to sport. Detailed preoperative planning, meticulous surgical technique, and a comprehensive rehabilitation program are essential components to achieving a satisfactory result. PMID:26502444
Ocular surface reconstruction update.
Shimmura, Shigeto; Tsubota, Kazuo
2002-08-01
Ocular surface reconstruction (OSR) is now a standard procedure in the treatment of severe ocular surface disorders. The past few years have revealed the long-term results of patients who were operated on during the early stages of OSR development, and we now have a more realistic view of the benefits and limits of the procedure. On the other hand, further understanding of the physiologic role played by the amniotic membrane (AM) has opened doors to further refined techniques in treating these patients. This review will introduce some of the major contributions made during the past years in the advancement of OSR. Clinically, we are at a stage of reviewing the pros and cons of the various transplantation techniques. Identification of factors crucial for a successful OSR procedure will further improve surgical results. Basic researchers are on the verge of identifying the so-called limbal stem cells, and further understanding of AM physiology will lead the way to tissue engineering techniques as another alternative in OSR surgery.
NASA Astrophysics Data System (ADS)
Albrecht, H.; Binder, U.; Böckmann, P.; Gläser, R.; Harder, G.; Lembke-Koppitz, I.; Schmidt-Parzefall, W.; Schröder, H.; Schulz, H. D.; Wurth, R.; Yagil, A.; Donker, J. P.; Drescher, A.; Kamp, D.; Matthiesen, U.; Scheck, H.; Spaan, B.; Spengler, J.; Wegener, D.; Gabriel, J. C.; Schubert, K. R.; Stiewe, J.; Strahl, K.; Waldi, R.; Weseler, S.; Edwards, K. W.; Frisken, W. R.; Gilkinson, D. J.; Gingrich, D. M.; Kapitza, H.; Kim, P. C. H.; Kutschke, R.; Macfarlane, D. B.; McKenna, J. A.; McLean, K. W.; Nilsson, A. W.; Orr, R. S.; Padley, P.; Parsons, J. A.; Patel, P. M.; Prentice, J. D.; Seywerd, H. C. J.; Swain, J. D.; Tsipolitis, G.; Yoon, T.-S.; Yun, J. C.; Ammar, R.; Coppage, D.; Davis, R.; Kanekal, S.; Kwak, N.; Boštjančič, B.; Kernel, G.; Pleško, M.; Jönsson, L.; Babaev, A.; Danilov, M.; Golutvin, A.; Gorelov, I.; Lubimov, V.; Matveev, V.; Nagovitsin, V.; Ryltsov, V.; Semenov, A.; Shevchenko, V.; Soloshenko, V.; Tchistilin, V.; Tichomirov, I.; Zaitzev, Yu.; Childers, R.; Darden, C. W.; Oku, Y.; Gennow, H.; Argus Collaboration
1987-02-01
B mesons have been reconstructed in five decay channels of the type B→D ∗±nπ(n=1,2,3) using data accumulated by the ARGUS experiment at the e +e - storage ring DORIS II at DESY. In total, we find 40 neutral B mesons above a background of 15±6 events with a mass of (5278.2±1.0±3.0) MeV/ c2 and 32 charged B mesons above a background of 17±6 events with a mass of (5275.8±1.3±3.0) MeV/ c2. The decays overlineB0D∗+π -π 0, overlineB0D∗+π -π -π +, and B-→ D∗+π -π -π 0 have been observed for the first time. We find substantially smaller branching ratios for the decay modes overlineB0→ D∗+π - and B-→ D∗+π -π - than previously published by the CLEO collaboration.
Problems of reconstruction during pancreatoduodenectomy.
Sakorafas, G H; Friess, H; Balsiger, B M; Büchler, M W; Sarr, M G
2001-01-01
Pancreatoduodenectomy may be a difficult operation, not only during the resectional part of the procedure, but also during reconstruction. Usually, these problems are due to local conditions of the organs/tissues, such as small diameter of the common bile duct or pancreatic duct, friable soft pancreas, vascular anomalies, etc. Reconstruction may also be problematic because of the hemodynamic instability of the patient during surgery (subsequent to massive hemorrhage), and in those unusual cases, delayed reconstruction may be a life-saving, wise choice.
Reconstruction of the alar groove.
Chait, L A; Fayman, M S
1989-05-01
The obliteration of a well-defined alar groove is common after nasal alar reconstruction. A method is described that can be used at the time of reconstruction to ensure the continued definition of the groove or to restore it in cases where it has been obliterated. The technique is based on the natural tendency of the skin to tube itself. Cheek skin is advanced beneath the posterior free edge of the reconstructed ala so that this edge now comes into contact with an epidermal surface. As this edge now tends to tube itself, a natural alar groove is produced. This method has been used successfully in six cases.
Breast Reconstruction with Flap Surgery
... that restores shape to your breast after a mastectomy — surgery that removes your breast tissue to treat ... can be accomplished at the time of your mastectomy (immediate reconstruction), though sometimes it can be done ...
Vermilion Reconstruction with Genital Mucosa
Weyandt, Gerhard H.; Woeckel, Achim; Kübler, Alexander C.
2016-01-01
Summary: Functional and aesthetical reconstruction, especially of the upper lip after ablative tumor surgery, can be very challenging. The skin of the lip might be sufficiently reconstructed by transpositional flaps from the nasolabial or facial area. Large defects of the lip mucosa, including the vestibule, are even more challenging due to the fact that flaps from the inner lining of the oral cavity often lead to functional impairments. We present a case of multiple vermilion and skin resections of the upper lip. At the last step, we had to resect even the whole vermilion mucosa, including parts of the oral mucosa of the vestibule, leaving a bare orbicularis oris muscle. To reconstruct the mucosal layer, we used a mucosal graft from the labia minora and placed it on the compromised lip and the former transpositional flaps for the reconstructed skin of the upper lip with very good functional and aesthetic results. PMID:27579226
Vermilion Reconstruction with Genital Mucosa.
Müller-Richter, Urs D A; Weyandt, Gerhard H; Woeckel, Achim; Kübler, Alexander C
2016-05-01
Functional and aesthetical reconstruction, especially of the upper lip after ablative tumor surgery, can be very challenging. The skin of the lip might be sufficiently reconstructed by transpositional flaps from the nasolabial or facial area. Large defects of the lip mucosa, including the vestibule, are even more challenging due to the fact that flaps from the inner lining of the oral cavity often lead to functional impairments. We present a case of multiple vermilion and skin resections of the upper lip. At the last step, we had to resect even the whole vermilion mucosa, including parts of the oral mucosa of the vestibule, leaving a bare orbicularis oris muscle. To reconstruct the mucosal layer, we used a mucosal graft from the labia minora and placed it on the compromised lip and the former transpositional flaps for the reconstructed skin of the upper lip with very good functional and aesthetic results.
Study of cluster reconstruction and track fitting algorithms for CGEM-IT at BESIII
NASA Astrophysics Data System (ADS)
Guo, Yue; Wang, Liang-Liang; Ju, Xu-Dong; Wu, Ling-Hui; Xiu, Qing-Lei; Wang, Hai-Xia; Dong, Ming-Yi; Hu, Jing-Ran; Li, Wei-Dong; Li, Wei-Guo; Liu, Huai-Min; Qun, Ou-Yang; Shen, Xiao-Yan; Yuan, Ye; Zhang, Yao
2016-01-01
Considering the effects of aging on the existing Inner Drift Chamber (IDC) of BESIII, a GEM-based inner tracker, the Cylindrical-GEM Inner Tracker (CGEM-IT), is proposed to be designed and constructed as an upgrade candidate for the IDC. This paper introduces a full simulation package for the CGEM-IT with a simplified digitization model, and describes the development of software for cluster reconstruction and track fitting, using a track fitting algorithm based on the Kalman filter method. Preliminary results for the reconstruction algorithms which are obtained using a Monte Carlo sample of single muon events in the CGEM-IT, show that the CGEM-IT has comparable momentum resolution and transverse vertex resolution to the IDC, and a better z-direction resolution than the IDC. Supported by National Key Basic Research Program of China (2015CB856700), National Natural Science Foundation of China (11205184, 11205182) and Joint Funds of National Natural Science Foundation of China (U1232201)
Should I Have Breast Reconstruction?
... I choose not to have breast reconstruction? Many women decide that breast reconstruction is not right for them. Or they might not be able ... Reports of Anaplastic Large Cell Lymphoma (ALCL) in Women with Breast Implants, January 26, 2011. Accessed at www.fda.gov/MedicalDevices/Safety/AlertsandNotices/ucm240000.htm on June 1, ... Site Comments © 2017 American Cancer Society, Inc. All rights reserved. The American Cancer Society is a qualified ...
Equilibrium Reconstruction in EAST Tokamak
NASA Astrophysics Data System (ADS)
Qian, Jinping; Wan, Baonian; L. Lao, L.; Shen, Biao; A. Sabbagh, S.; Sun, Youwen; Liu, Dongmei; Xiao, Bingjia; Ren, Qilong; Gong, Xianzu; Li, Jiangang
2009-04-01
Reconstruction of experimental axisymmetric equilibria is an important part of tokamak data analysis. Fourier expansion is applied to reconstruct the vessel current distribution in EFIT code. Benchmarking and testing calculations are performed to evaluate and validate this algorithm. Two cases for circular and non-circular plasma discharges are presented. Fourier expansion used to fit the eddy current is a robust method and the real time EFIT can be introduced to the plasma control system in the coming campaign.
Performance of Tracking, b-tagging and Jet/MET reconstruction at the CMS High Level Trigger
NASA Astrophysics Data System (ADS)
Tosi, Mia
2015-12-01
The trigger systems of the LHC detectors play a crucial role in determining the physics capabilities of experiments. In 2015, the center-of-mass energy of proton-proton collisions will reach 13 TeV up to an unprecedented luminosity of 1 × 1034 cm-2s-1. A reduction of several orders of magnitude of the event rate is needed to reach values compatible with detector readout, offline storage and analysis capabilities. The CMS experiment has been designed with a two-level trigger system: the Level-1 Trigger (L1T), implemented on custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the offline reconstruction software running on a computer farm. A software trigger system requires a trade-off between the complexity of the algorithms, the sustainable output rate, and the selection efficiency. With the computing power available during the 2012 data taking the maximum reconstruction time at HLT was about 200 ms per event, at the nominal L1T rate of 100 kHz. Tracking algorithms are widely used in the HLT in the object reconstruction through particle-flow techniques as well as in the identification of b-jets and lepton isolation. Reconstructed tracks are also used to distinguish the primary vertex, which identifies the hard interaction process, from the pileup ones. This task is particularly important in the LHC environment given the large number of interactions per bunch crossing: on average 25 in 2012, and expected to be around 40 in Run II with a large contribution from out-of-time particles. In order to cope with tougher conditions the tracking and vertexing techniques used in 2012 have been largely improved in terms of timing and efficiency in order to keep the physics reach at the level of Run I conditions. We will present the performance of these newly developed algorithms, discussing their impact on the b-tagging performances as well as on the jet and missing transverse energy reconstruction.
Technical basis for dose reconstruction
Anspaugh, L.R.
1996-01-31
The purpose of this paper is to consider two general topics: technical considerations of why dose-reconstruction studies should or should not be performed and methods of dose reconstruction. The first topic is of general and growing interest as the number of dose-reconstruction studies increases, and one asks the question whether it is necessary to perform a dose reconstruction for virtually every site at which, for example, the Department of Energy (DOE) has operated a nuclear-related facility. And there is the broader question of how one might logically draw the line at performing or not performing dose-reconstruction (radiological and chemical) studies for virtually every industrial complex in the entire country. The second question is also of general interest. There is no single correct way to perform a dose-reconstruction study, and it is important not to follow blindly a single method to the point that cheaper, faster, more accurate, and more transparent methods might not be developed and applied.
Costal Grafting in Mandibular Reconstruction
Bourlet, Jerôme; Château, Joseph; Jacquemart, Mathieu; Dufour, Clémence; Mojallal, Ali; Gleizal, Arnaud
2015-01-01
Background: Reconstruction of mandibular bone defect is a common indication in craniomaxillofacial surgery, and free fibular flap is the gold standard for this indication. However, there are alternatives; nonvascular bone grafting is one of them, and we present the costal grafting for mandibular reconstruction, a classic technique that is reliable, efficient, and produced less morbidity than the technique of using composite free flaps. Method: A 9-year retrospective review of 54 patients treated surgically for mandibular reconstruction was performed. The criterion mainly analyzed was graft survival. The surgical technique was described in detail. Results: A total of 54 patients with mandibular bone defect were identified. Five symphysis, 46 corpus, and 20 ramus defects were considered. These patients underwent reconstruction by costal grafting, and the engrafting was successful in 92.6% of cases. Dental rehabilitation with dental implants was realized in 70% of cases. Conclusions: The approach described in this article allowed the authors to obtain good results with costal grafting for mandibular reconstruction and dental rehabilitation. Costal grafting is a good alternative for fibula free flap in specific indications. Reconstruction of mandibular bone defect is a common indication in craniomaxillofacial surgery. Since the 1980s, the gold standard for these defects is the use of free fibular flap.1 In some cases, this technique is contradicted; the surgeon then has several possibilities for the use of free osteomyocutaneous flaps (iliac crest, scapula, and serrato-costal flaps).2–8 PMID:26893990
Mandibular reconstruction with different techniques.
Torroni, Andrea; Marianetti, Tito Matteo; Romandini, Mario; Gasparini, Giulio; Cervelli, Daniele; Pelo, Sandro
2015-05-01
Traumas, malformative or dysplastic pathologies, atrophy, osteoradionecrosis, and benign or malignant neoplasm can cause bone deficits in the mandible. Consequent mandibular defects can determine aesthetic and functional problems; therefore, being able to perform a good reconstruction is of critical importance.Several techniques have been proposed for mandibular reconstruction over the years. In this article, we present and discuss the evolution during the time of the methods of mandible reconstruction as well as pros and cons of each procedure on the basis of experience of 10 years in the maxillofacial department of the Catholic University of Sacred Heart of Rome.Free flaps represent the gold standard method of reconstruction of large mandibular defects: the fibula bone flap represents the best choice for large defects involving the arch and the mandibular ramus, whereas the deep circumflex iliac artery represents a valid alternative for mandibular defects involving the posterior region.In cases where free flap reconstructions are contraindicated, the use of regional pedicle flap combined with autologous bone grafts still represents a valid choice. Patients who are not deemed suitable for long and demanding surgery can still be treated using alloplastic materials in association with regional pedicle flap or, when adjuvant radiation therapy is needed, by simple locoregional pedicle flap. Finally, in selected cases, the bone transporting technique should be considered as a valid alternative to the more "traditional" reconstructive methods because of the extraordinary potential and its favorable cost-benefit ratio.
Improving outcomes in aesthetic facial reconstruction.
Hofer, Stefan O P; Mureau, Marc A M
2009-07-01
Aesthetic facial reconstruction is a challenging art. Improving outcomes in aesthetic facial reconstruction requires a thorough understanding of the basic principles of the functional and aesthetic requirements for facial reconstruction. From there, further refinement and attention to detail can be provided. This paper discusses basic principles of aesthetic facial reconstruction.
Alloplastic adjuncts in breast reconstruction
Cabalag, Miguel S.; Rostek, Marie; Miller, George S.; Chae, Michael P.; Quinn, Tam; Rozen, Warren M.
2016-01-01
Background There has been an increasing role of acellular dermal matrices (ADMs) and synthetic meshes in both single- and two-stage implant/expander breast reconstruction. Numerous alloplastic adjuncts exist, and these vary in material type, processing, storage, surgical preparation, level of sterility, available sizes and cost. However, there is little published data on most, posing a significant challenge to the reconstructive surgeon trying to compare and select the most suitable product. The aims of this systematic review were to identify, summarize and evaluate the outcomes of studies describing the use of alloplastic adjuncts for post-mastectomy breast reconstruction. The secondary aims were to determine their cost-effectiveness and analyze outcomes in patients who also underwent radiotherapy. Methods Using the PRSIMA 2009 statement, a systematic review was conducted to find articles reporting on the outcomes on the use of alloplastic adjuncts in post-mastectomy breast reconstruction. Multiple databases were searched independently by three authors (Cabalag MS, Miller GS and Chae MP), including: Ovid MEDLINE (1950 to present), Embase (1980 to 2015), PubMed and Cochrane Database of Systematic Reviews. Results Current published literature on available alloplastic adjuncts are predominantly centered on ADMs, both allogeneic and xenogeneic, with few outcome studies available for synthetic meshes. Outcomes on the 89 articles, which met the inclusion criteria, were summarized and analyzed. The reported outcomes on alloplastic adjunct-assisted breast reconstruction were varied, with most data available on the use of ADMs, particularly AlloDerm® (LifeCell, Branchburg, New Jersey, USA). The use of ADMs in single-stage direct-to-implant breast reconstruction resulted in lower complication rates (infection, seroma, implant loss and late revision), and was more cost effective when compared to non-ADM, two-stage reconstruction. The majority of studies demonstrated
Reconstruction from divergent ray projections
NASA Astrophysics Data System (ADS)
Sastry, C. S.; Singh, Santosh
2012-03-01
Despite major advances in x-ray sources, detector arrays, gantry mechanical design and special computer performances, computed tomography (CT) enjoys the filtered back projection (FBP) algorithm as its first choice for the CT image reconstruction in the commercial scanners [1]. Over the years, a lot of fundamental work has been done in the area of finding the sophisticated solutions for the inverse problems using different kinds of optimization techniques. Recent literature in applied mathematics is being dominated by the compressive sensing techniques and/or sparse reconstruction techniques [2], [3]. Still there is a long way to go for translating these newly developed algorithms in the clinical environment. The reasons are not obvious and seldom discussed [1]. Knowing the fact that the filtered back projection is one of the most popular CT image reconstruction algorithms, one pursues research work to improve the different error estimates at different steps performed in the filtered back projection. In this paper, we present a back projection formula for the reconstruction of divergent beam tomography with unique convolution structure. Using such a proposed approximate convolution structure, the approximation error mathematically justifies that the reconstruction error is low for a suitable choice of parameters. In order to minimize the exposure time and possible distortions due to the motion of the patient, the fan beam method of collection of data is used. Rebinning [4] transformation is used to connect fan beam data into parallel beam data so that the well developed methods of image reconstruction for parallel beam geometry can be used. Due to the computational errors involved in the numerical process of rebinning, some degradation of image is inevitable. However, to date very little work has been done for the reconstruction of fan beam tomography. There have been some recent results [5], [6] on wavelet reconstruction of divergent beam tomography. In this paper
Cunningham, R.; Bernardin, J.D.; Simon-Gillo, J.
1997-11-01
This report presents a summary of an experimental investigation of a closed loop air cooling system designed to control the temperature and humidity in the main enclosure of the multiplicity and vertex detector (MVD). Measurements of the cooling air flow rate, the humidity levels inside and outside of the MVD, and the cooling air temperatures were used to assess the performance of the system and to characterize the system limitations and potential assembly problems. The results of the study indicate that several design changes are needed in the final design to meet the temperature and humidity operating requirements. A thorough set of design change recommendations that satisfy these operating criteria completes this report.
Ulnar Collateral Ligament Reconstruction
Erickson, Brandon J.; Bach, Bernard R.; Cohen, Mark S.; Bush-Joseph, Charles A.; Cole, Brian J.; Verma, Nikhil N.; Nicholson, Gregory P.; Romeo, Anthony A.
2016-01-01
Background: Ulnar collateral ligament reconstruction (UCLR) is a common surgery performed in professional, collegiate, and high school athletes. Purpose: To report patient demographics, surgical techniques, and outcomes of all UCLRs performed at a single institution from 2004 to 2014. Study Design: Case series; Level of evidence, 4. Methods: All patients who underwent UCLR from January 1, 2004, through December 31, 2014, at a single institution were identified. Charts were reviewed to determine patient age, sex, date of surgery, sport played, athletic level, surgical technique, graft type, and complications. Data were collected prospectively, and patients were contacted via phone calls to obtain the return-to-sport rate, Conway-Jobe score, Andrews-Timmerman score, and Kerlan-Jobe Orthopaedic Clinic (KJOC) Shoulder and Elbow score. Continuous variable data were reported as weighted means, and categorical variable data were reported as frequencies with percentages. Results: A total of 187 patients (188 elbows) underwent UCLR during the study period (92% male; mean age, 19.6 ± 4.7 years; 78.2% right elbows). There were 165 baseball players (87.8% of all patients), 155 of whom were pitchers (82.5% of all patients). Ninety-seven (51.6%) were college athletes, 68 (36.2%) high school athletes, and 7 (3.7%) professional athletes at the time of surgery. The docking technique was used in 110 (58.5%) patients while the double-docking technique was used in 78 (41.5%). An ipsilateral palmaris longus graft was used in 110 (58.5%) patients while a hamstring autograft was used in 48 (25.5%) patients. The ulnar nerve was subcutaneously transposed in 79 (42%) patients. Clinical follow-up data were available on 85 patients. Mean follow-up was 60 ± 30.8 months. Overall, 94.1% of patients were able to return to sport and had a Conway-Jobe score of good/excellent while 4.3% had a score of fair. The mean KJOC score was 90.4 ± 6.7 and mean Andrews-Timmerman score was 92.5 ± 7
Niche reconstructive techniques for complex abdominal wall reconstruction: a review.
Sue, Gloria R; Narayan, Deepak
2014-04-01
Abdominal wall defects resulting from recurrent hernias, trauma, and radiation necrosis are difficult and challenging to repair given the high rates of recurrence and surgical morbidity. Complex abdominal wall defects often require the transposition of autologous material to bridge the fascial gap. We present a review of niche reconstructive techniques that have been used in complex abdominal wall repair. The specific techniques reviewed include use of delayed and tunneled pedicled tensor fascia lata myofascial flap, de-epithelialized flap closure, free latissimus dorsi myocutaneous flap with or without innervation, and abdominal wall transplant. These niche surgical techniques have great potential to reduce recurrence rates when used in the proper setting for complex abdominal wall reconstruction. More studies are needed to evaluate the relative use of these techniques with the more widely established surgical methods of reconstruction.
Structural reconstruction of protein ancestry.
Rouet, Romain; Langley, David B; Schofield, Peter; Christie, Mary; Roome, Brendan; Porebski, Benjamin T; Buckle, Ashley M; Clifton, Ben E; Jackson, Colin J; Stock, Daniela; Christ, Daniel
2017-03-29
Ancestral protein reconstruction allows the resurrection and characterization of ancient proteins based on computational analyses of sequences of modern-day proteins. Unfortunately, many protein families are highly divergent and not suitable for sequence-based reconstruction approaches. This limitation is exemplified by the antigen receptors of jawed vertebrates (B- and T-cell receptors), heterodimers formed by pairs of Ig domains. These receptors are believed to have evolved from an extinct homodimeric ancestor through a process of gene duplication and diversification; however molecular evidence has so far remained elusive. Here, we use a structural approach and laboratory evolution to reconstruct such molecules and characterize their interaction with antigen. High-resolution crystal structures of reconstructed homodimeric receptors in complex with hen-egg white lysozyme demonstrate how nanomolar affinity binding of asymmetrical antigen is enabled through selective recruitment and structural plasticity within the receptor-binding site. Our results provide structural evidence in support of long-held theories concerning the evolution of antigen receptors, and provide a blueprint for the experimental reconstruction of protein ancestry in the absence of phylogenetic evidence.
[Reconstructive surgery in larynx cancer].
Szmeja, Z; Szyfter, W; Leszczyńska, M; Wierzbicka, M; Golusiński, W; Dabrowski, P; Karlik, M
2000-01-01
Subtotal laryngectomies with larynx reconstruction are an acceptable alternative to the total laryngectomy in T2, T3 larynx cancer treatment. One procedure resection and reconstruction allow for radical oncological treatment with simultaneous preservation of air passage continuity and the function of the neolarynx. In the years 1988-1997 in ENT Dept. of Karol Marcinkowski University of Medical Sciences 38 subtotal laryngectomies with larynx reconstruction were performed. They were: 34 supracricoid laryngectomies with cricohyoidopexy, 2 with epiglotohyoidopexy and 3 supraglotic laryngectomies with reconstruction. The basic criterion of the evaluation of such procedures effectiveness was their oncological radicality. The follow-up period ranged from 2 to 9 years. Local relapse was observed in none of the cases, nodal relapse was started in 2 patients. Another aspect taken into consideration was the function of the neolarynx. In 3 cases two or three laser procedures were performed because of neolarynx lumen structure which were followed by T-dren plasty. In 10 patients temporary swallowing difficulties, especially liquids, were observed in the first three month. Gastrostomy was performed in one case. The authors discuss indications to this type of surgery, operation technique, oncological and functional results. Spirometry results and voice analyses after larynx resection and reconstruction in these patients are presented.
Chang, Yao-Wen; Jin, Bih-Yaw
2012-01-14
Many-body perturbation theory is used to investigate the effect of π-electron correlations on the quasi-particle band structures of conjugated polymers at the level of the Pariser-Parr-Pople model. The self-consistent GW approximation with vertex corrections to both the self-energy and the polarization in Hedin's equations is employed in order to eliminate self-interaction errors and include the effects of electron-hole attraction in screening processes. The dynamic inverse dielectric function is constructed from the generalized plasmon-pole approximation with the static dressed polarization given by the coupled-perturbed Hartree-Fock equation. The bandgaps of trans-polyacetylene, trans-polyphenylenevinylene and poly(para)phenylene are calculated by both the Hartree-Fock and GW approximation, and a lowering of bandgaps due to electron correlations is found. We conclude that both dielectric screening and vertex corrections are important for calculating the quasi-particle bandgaps of conjugated polymers.
Reconstructing Ancient Forms of Life
NASA Technical Reports Server (NTRS)
Benner, Steven A.
1998-01-01
Progress in the past three months has occurred in two areas, reconstruction of ancestral proteins and improved understanding of chemical features that are likely to be universal in generic matter regardless of its genesis. Ancestral ribonucleases have been reconstructed, and an example has been developed that shows how physiological function can be assigned to in vitro behaviors observed in biological systems. Sequence data have been collected to permit the reconstruction of src homology 2 domains that underwent radiative divergence at the time of the radiative divergence of chordates. New studies have been completed that show how genetic matter (or its remnants) might be detected on Mars (or other non-terrean locations.) Last, the first in vitro selection experiments have been completed using a nucleoside library carrying positively charged functionality, illustrating the importance of non-standard nucleotides to those attempting to obtain evidence for an "RNA world" as an early episode of life on earth.
Reconstructive options for periocular defects.
Jewett, B S; Shockley, W W
2001-06-01
Reconstruction of the periorbital area following skin cancer excision requires a thorough knowledge of orbital anatomy and eyelid function. Reconstructive procedures should maintain the function of periorbital structures while attempting to achieve optimal cosmesis. Generally, eyelid reconstruction can be considered in terms of the thickness and overall size of the defect. Both the anterior and posterior lamella should be restored, and at least one of these layers needs to be vascularized. The integrity of the canthal tendons should also be addressed. If severed, the tendons should be attached to bony landmarks in order to recreate the proper curvature of the eyelid against the globe. Finally, defects involving the lacrimal system should be assessed and properly reconstituted.
Using clustering for document reconstruction
NASA Astrophysics Data System (ADS)
Ukovich, Anna; Zacchigna, Alessandra; Ramponi, Giovanni; Schoier, Gabriella
2006-02-01
In the forensics and investigative science fields there may arise the need of reconstructing documents which have been destroyed by means of a shredder. In a computer-based reconstruction, the pieces are described by numerical features, which represent the visual content of the strips. Usually, the pieces of different pages have been mixed. We propose an approach for the reconstruction which performs a first clustering on the strips to ease the successive matching, be it manual (with the help of a computer) or automatic. A number of features, extracted by means of image processing algorithms, have been selected for this aim. The results show the effectiveness of the features and of the proposed clustering algorithm.
Shape Reconstruction from Generalized Projections
NASA Astrophysics Data System (ADS)
Viikinkoski, Matti
2016-01-01
In this thesis we develop methods for recovering the three-dimensional shape of an object from generalized projections. We particularly focus on the problems encountered when data are presented as discrete image fields. We demonstrate the usefulness of the Fourier transform in transferring the image data and shape model projections to a domain more suitable for gradient based optimization. To substantiate the general applicability of our methods to observational astronomy, we reconstruct shape models for several asteroids observed with adaptive optics, thermal infrared interferometry, or range-Doppler radar. The reconstructions are carried out with the ADAM software package that we have designed for general use.
[Tissue engineering in reconstructive urology].
Engel, O; Soave, A; Rink, M; Dahlem, R; Hellwinkel, O; Chun, F K; Fisch, M
2015-05-01
The term tissue engineering incorporates various techniques for the production of replacement tissues and organs. In urology tissue engineering offers many promising possibilities for the reconstruction of the urinary tract. Currently, buccal mucosa and urothelial cells are most commonly used for tissue engineering of the urinary tract. Various materials have been tested for their suitability as tissue scaffolds. The ideal scaffold, however, has not yet been found. In addition to material sciences and cell culture methods, surgical techniques play an important role in reconstructive urology for the successful implantation of tissue engineered transplants.
Plane-based optimization for 3D object reconstruction from single line drawings.
Liu, Jianzhuang; Cao, Liangliang; Li, Zhenguo; Tang, Xiaoou
2008-02-01
In previous optimization-based methods of 3D planar-faced object reconstruction from single 2D line drawings, the missing depths of the vertices of a line drawing (and other parameters in some methods) are used as the variables of the objective functions. A 3D object with planar faces is derived by finding values for these variables that minimize the objective functions. These methods work well for simple objects with a small number N of variables. As N grows, however, it is very difficult for them to find expected objects. This is because with the nonlinear objective functions in a space of large dimension N, the search for optimal solutions can easily get trapped into local minima. In this paper, we use the parameters of the planes that pass through the planar faces of an object as the variables of the objective function. This leads to a set of linear constraints on the planes of the object, resulting in a much lower dimensional nullspace where optimization is easier to achieve. We prove that the dimension of this nullspace is exactly equal to the minimum number of vertex depths which define the 3D object. Since a practical line drawing is usually not an exact projection of a 3D object, we expand the nullspace to a larger space based on the singular value decomposition of the projection matrix of the line drawing. In this space, robust 3D reconstruction can be achieved. Compared with two most related methods, our method not only can reconstruct more complex 3D objects from 2D line drawings, but also is computationally more efficient.
Current status of breast reconstruction after mastectomy.
Handel, N
1991-11-01
Breast reconstruction after mastectomy can make an important contribution to the quality of life of women with breast cancer. Reconstruction eliminates the need for a cumbersome external prosthesis, allows greater freedom in the selection of clothing styles, and makes a woman more comfortable undressing in front of others. Reconstruction also reduces anxiety and depression and helps a woman regain a sense of wholeness and femininity. Advances in breast reconstruction include improved types of implants, use of autogenous tissues, and refinements in nipple reconstruction. This article summarizes the "state of the art" in breast reconstruction, the various surgical techniques available, their indications, advantages, and potential drawbacks.
The reconstructive microsurgery ladder in orthopaedics.
Tintle, Scott M; Levin, L Scott
2013-03-01
Since the advent of the operating microscope by Julius Jacobson in 1960, reconstructive microsurgery has become an integral part of extremity reconstruction and orthopaedics. During World War I, with the influx of severe extremity trauma Harold Gillies introduced the concept of the reconstructive ladder for wound closure. The concept of the reconstructive ladder goes from simple to complex means of attaining wound closure. Over the last half century microsurgery has continued to evolve and progress. We now have a microsurgical reconstructive ladder. The microsurgical reconstruction ladder is based upon the early work on revascularization and replantation extending through the procedures that are described in this article.
Reconstructing Death in Postmodern Society.
ERIC Educational Resources Information Center
Kastenbaum, Robert
1993-01-01
Examines interaction between emerging thanatological movement and its sociohistorical context. Notes that thanatology will take on new shape as individuals and society attempt to cope with postmodernistic forces and deconstructive mentality. Considers prospect for authentic solidarity against distress in reconstructed death system. (Author/NB)
Computational methods for image reconstruction.
Chung, Julianne; Ruthotto, Lars
2017-04-01
Reconstructing images from indirect measurements is a central problem in many applications, including the subject of this special issue, quantitative susceptibility mapping (QSM). The process of image reconstruction typically requires solving an inverse problem that is ill-posed and large-scale and thus challenging to solve. Although the research field of inverse problems is thriving and very active with diverse applications, in this part of the special issue we will focus on recent advances in inverse problems that are specific to deconvolution problems, the class of problems to which QSM belongs. We will describe analytic tools that can be used to investigate underlying ill-posedness and apply them to the QSM reconstruction problem and the related extensively studied image deblurring problem. We will discuss state-of-the-art computational tools and methods for image reconstruction, including regularization approaches and regularization parameter selection methods. We finish by outlining some of the current trends and future challenges. Copyright © 2016 John Wiley & Sons, Ltd.
[Reconstructive surgery for hand injuries].
Bouvet, Elisabeth
2012-05-01
Injuries to the hand requiring emergency treatment concern 1.4 million people a year in France. The creation of the European Federation of Emergency Services for the Hand (FESUM) has brought about an improvement in the quality of care. The aim of reconstructive surgery is to preserve the hand's ability to grasp, its mobility and agility, depending on the seriousness of the injuries.
Reconstructing Indo-European Syllabification
ERIC Educational Resources Information Center
Byrd, Andrew Miles
2010-01-01
The chief concern of this dissertation is to investigate a fundamental, yet unsolved problem within the phonology of Proto-Indo-European (PIE): the process of syllabification. I show that by analyzing the much more easily reconstructable word-edge clusters we may predict which types of consonant clusters can occur word-medially, provided that we…
Reconstruction: From the Students' Perspective.
ERIC Educational Resources Information Center
Schaeffer, Lys A.
1989-01-01
Presents two lesson plans for learning strategies employing the skills of empathy and reciprocity. The lessons cover the Black Codes developed during Reconstruction and the impeachment of Andrew Johnson. Lists objectives, instructional procedures, and makes suggestions for essay questions to be used in summative evaluation procedures. (KO)
Trigonometric Transforms for Image Reconstruction
1998-06-01
applying trigo - nometric transforms to image reconstruction problems. Many existing linear image reconstruc- tion techniques rely on knowledge of...ancestors. The research performed for this dissertation represents the first time the symmetric convolution-multiplication property of trigo - nometric...Fourier domain. The traditional representation of these filters will be similar to new trigo - nometric transform versions derived in later chapters
Eulerian BAO reconstructions and N -point statistics
NASA Astrophysics Data System (ADS)
Schmittfull, Marcel; Feng, Yu; Beutler, Florian; Sherwin, Blake; Chu, Man Yat
2015-12-01
As galaxy surveys begin to measure the imprint of baryonic acoustic oscillations (BAO) on large-scale structure at the subpercent level, reconstruction techniques that reduce the contamination from nonlinear clustering become increasingly important. Inverting the nonlinear continuity equation, we propose an Eulerian growth-shift reconstruction algorithm that does not require the displacement of any objects, which is needed for the standard Lagrangian BAO reconstruction algorithm. In real-space dark matter-only simulations the algorithm yields 95% of the BAO signal-to-noise obtained from standard reconstruction. The reconstructed power spectrum is obtained by adding specific simple 3- and 4-point statistics to the prereconstruction power spectrum, making it very transparent how additional BAO information from higher-point statistics is included in the power spectrum through the reconstruction process. Analytical models of the reconstructed density for the two algorithms agree at second order. Based on similar modeling efforts, we introduce four additional reconstruction algorithms and discuss their performance.
Roiban, R.; Tseytlin, A. A.
2010-11-15
We consider the leading large string tension correction to correlation functions of three vertex operators of particular massive string states in AdS{sub 5}xS{sup 5} string theory. We assume that two of these states are 'heavy' carrying large spins (of order string tension) and thus can be treated semiclassically while the third state is 'light' having fixed quantum numbers. We study several examples. In the case when the 'heavy' states are described by a folded string with large-spin in AdS{sub 5} the 3-point function scales as a semiclassical spin parameter of the 'heavy' state in power of the string level of the 'light' massive string state. We observe similar behavior in the case of 'heavy' states which admit a small angular momentum limit, which may thus represent creatures of three quantum massive string states.
Sau, Jay D; Tewari, Sumanta
2011-10-21
We study the diamagnetism of the six-vertex model with the arrows as directed bond currents. To our knowledge, this is the first study of the diamagnetism of this model. A special version of this model, called the F model, describes the thermal disordering transition of an orbital antiferromagnet, known as d-density wave, a proposed state for the pseudogap phase of the high-T(c) cuprates. We find that the F model is strongly diamagnetic and the susceptibility may diverge in the high-temperature critical phase with power-law arrow correlations. These results may explain the surprising recent observation of a diverging low-field diamagnetic susceptibility seen in some optimally doped cuprates within the d-density wave model of the pseudogap phase.
Dhayal, Rajendra S; Sahoo, Satyanarayan; Reddy, K Hari Krishna; Mobin, Shaikh M; Jemmis, Eluvathingal D; Ghosh, Sundargopal
2010-02-01
The reaction of the [(eta(5)-C(5)Me(5))MoCl(4)] complex with [LiBH(4).THF] in toluene at -70 degrees C, followed by pyrolysis at 110 degrees C, afforded dark brown [(eta(5)-C(5)Me(5)Mo)(3)MoB(9)H(18)], 2, in parallel with the known [(eta(5)-C(5)Me(5)Mo)(2)B(5)H(9)], 1. Compound 2 has been characterized in solution by (1)H, (11)B, and (13)C NMR spectroscopy and elemental analysis, and the structural types were unequivocally established by crystallographic studies. The title compound represents a novel class of vertex-fused clusters in which a Mo atom has been fused in a perpendicular fashion between two molybdaborane clusters. Electronic structure calculations employing density functional theory yield geometries in agreement with the structure determinations, and on grounds of density functional theory calculations, we have analyzed the bonding patterns in the structure.
Jaspers, Stijn; Verbeke, Geert; Böhning, Dankmar; Aerts, Marc
2016-01-01
In the last decades, considerable attention has been paid to the collection of antimicrobial resistance data, with the aim of monitoring non-wild-type isolates. This monitoring is performed based on minimum inhibition concentration (MIC) values, which are collected through dilution experiments. We present a semi-parametric mixture model to estimate the entire MIC density on the continuous scale. The parametric first component is extended with a non-parametric second component and a new back-fitting algorithm, based on the Vertex Exchange Method, is proposed. Our data example shows how to estimate the MIC density for Escherichia coli tested for ampicillin and how to use this estimate for model-based classification. A simulation study was performed, showing the promising behavior of the new method, both in terms of density estimation as well as classification.
Fingerprint reconstruction: from minutiae to phase.
Feng, Jianjiang; Jain, Anil K
2011-02-01
Fingerprint matching systems generally use four types of representation schemes: grayscale image, phase image, skeleton image, and minutiae, among which minutiae-based representation is the most widely adopted one. The compactness of minutiae representation has created an impression that the minutiae template does not contain sufficient information to allow the reconstruction of the original grayscale fingerprint image. This belief has now been shown to be false; several algorithms have been proposed that can reconstruct fingerprint images from minutiae templates. These techniques try to either reconstruct the skeleton image, which is then converted into the grayscale image, or reconstruct the grayscale image directly from the minutiae template. However, they have a common drawback: Many spurious minutiae not included in the original minutiae template are generated in the reconstructed image. Moreover, some of these reconstruction techniques can only generate a partial fingerprint. In this paper, a novel fingerprint reconstruction algorithm is proposed to reconstruct the phase image, which is then converted into the grayscale image. The proposed reconstruction algorithm not only gives the whole fingerprint, but the reconstructed fingerprint contains very few spurious minutiae. Specifically, a fingerprint image is represented as a phase image which consists of the continuous phase and the spiral phase (which corresponds to minutiae). An algorithm is proposed to reconstruct the continuous phase from minutiae. The proposed reconstruction algorithm has been evaluated with respect to the success rates of type-I attack (match the reconstructed fingerprint against the original fingerprint) and type-II attack (match the reconstructed fingerprint against different impressions of the original fingerprint) using a commercial fingerprint recognition system. Given the reconstructed image from our algorithm, we show that both types of attacks can be successfully launched against
Model Based Iterative Reconstruction for Bright Field Electron Tomography (Postprint)
2013-02-01
Reconstruction Technique ( SIRT ) are applied to the data. Model based iterative reconstruction (MBIR) provides a powerful framework for tomographic...the reconstruction when the typical algorithms such as Filtered Back Projection (FBP) and Simultaneous Iterative Reconstruction Technique ( SIRT ) are
Direct reconstruction of dark energy.
Clarkson, Chris; Zunckel, Caroline
2010-05-28
An important issue in cosmology is reconstructing the effective dark energy equation of state directly from observations. With so few physically motivated models, future dark energy studies cannot only be based on constraining a dark energy parameter space. We present a new nonparametric method which can accurately reconstruct a wide variety of dark energy behavior with no prior assumptions about it. It is simple, quick and relatively accurate, and involves no expensive explorations of parameter space. The technique uses principal component analysis and a combination of information criteria to identify real features in the data, and tailors the fitting functions to pick up trends and smooth over noise. We find that we can constrain a large variety of w(z) models to within 10%-20% at redshifts z≲1 using just SNAP-quality data.
Hanford Environmental Dose Reconstruction Project
Finch, S.M.
1990-09-01
This monthly report summarizes the technical progress and project status for the Hanford Environmental Dose Reconstruction (HEDR) Project being conducted at the Pacific Northwest Laboratory (PNL) under the direction of a Technical Steering Panel (TSP). The TSP is composed of experts in numerous technical fields related to this project and represents the interests of the public. The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms, environmental transport, environmental monitoring data, demographics, agriculture, food habits, environmental pathways and dose estimates. 3 figs.
Numerical reconstruction of optical surfaces.
Nam, Jayoung; Rubinstein, Jacob
2008-07-01
There are several problems in optics that involve the reconstruction of surfaces such as wavefronts, reflectors, and lenses. The reconstruction problem often leads to a system of first-order differential equations for the unknown surface. We compare several numerical methods for integrating differential equations of this kind. One class of methods involves a direct integration. It is shown that such a technique often fails in practice. We thus consider one method that provides an approximate direct integration; we show that it is always converging and that it provides a stable, accurate solution even in the presence of measurement noise. In addition, we consider a number of methods that are based on converting the original equation into a minimization problem.
X-Ray Tomographic Reconstruction
Bonnie Schmittberger
2010-08-25
Tomographic scans have revolutionized imaging techniques used in medical and biological research by resolving individual sample slices instead of several superimposed images that are obtained from regular x-ray scans. X-Ray fluorescence computed tomography, a more specific tomography technique, bombards the sample with synchrotron x-rays and detects the fluorescent photons emitted from the sample. However, since x-rays are attenuated as they pass through the sample, tomographic scans often produce images with erroneous low densities in areas where the x-rays have already passed through most of the sample. To correct for this and correctly reconstruct the data in order to obtain the most accurate images, a program employing iterative methods based on the inverse Radon transform was written. Applying this reconstruction method to a tomographic image recovered some of the lost densities, providing a more accurate image from which element concentrations and internal structure can be determined.
Reconstructing Weighted Networks from Dynamics
NASA Astrophysics Data System (ADS)
Ching, Emily S. C.; Lai, P. Y.; Leung, C. Y.
2015-03-01
The knowledge of how the different nodes of a network interact or link with one another is crucial for the understanding of the collective behavior and the functionality of the network. We have recently developed a method that can reconstruct both the links and their relative coupling strength of bidirectional weighted networks. Our method requires only measurements of node dynamics as input and is based on a relation between the pseudo-inverse of the matrix of the correlation of the node dynamics and the Laplacian matrix of the weighted network. Using several examples of different dynamics, we demonstrate that our method can accurately reconstruct the connectivity as well as the weights of the links for weighted random and weighted scale-free networks with both linear and nonlinear dynamics. The work of ESCC and CYL has been supported by the Hong Kong Research Grants Council under Grant No. CUHK 14300914.
Hanford Environmental Dose Reconstruction Project
Finch, S.M.; McMakin, A.H.
1992-01-01
The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source Terms, Environmental Transport, Environmental Monitoring Data, Demography, Food Consumption, and Agriculture, and Environmental Pathways and Dose Estimates.
Mycotic Infection post ACL Reconstruction
Costa-Paz, Matias; Ayerza, Miguel; Carbo, Lisandro; Sanchez, Marisa; Yacuzzi, Carlos; Muscolo, Luis
2017-01-01
Objectives: There are several studies in literature of septic arthritis after the ACL arthroscopic reconstruction related to bacterial germs. However, fungi infection is likely infrequent generating a massive bone loss with a catastrophic result. The purpose of this study was to describe preventive measures to decrease the mycotic infection after ACL reconstruction. Methods: Since 2005, we have diagnosed and treated 22 immunocompetent patients who underwent a surgery of an ACL lesion in other institutions in the country. Form these cases, we analyzed 19 which developed mycotic infection and an oncologic debridement was performed to control the pathology. In this series, we considered the initial surgery, the number of toilettes performed until their referral, magnitude of bone loss and final outcome. There were 5 other patients who consulted for mucormycosis, who finally were treated in other hospitals. Results: Epidemiology of mucormycosis is not clear. The exact cause is unknown due to heterogeneous data, different places and surgeons, facilities and type of surgical instruments in this series. In spite of not knowing the cause of the infection, several alternatives were evaluated in a non systematic way. Most of them related to the surgery room, sterilization place of the surgical tools, use of sterilizing liquids, cleanliness of lumen and cannulated bits. Instruments used during surgery were also evaluated: fields, shaver blades, drill types, ACL reconstruction fixation method. It is doubtful if the type of graft to reconstruct the ACL had any relation with infections. Among ideal preventive measures, the following are described: Surgery room with temperature and humidity control. Not using sterilizing liquids. Optimal preparation of surgical tools with adequate cleanliness of lumen and cannulated bits performed by adequate personnel. Sterilize in the same place where the surgery will be performed. Use of adequate instruments. The use of the central third of
Hanford Environmental Dose Reconstruction Project
Finch, S.M.; McMakin, A.H.
1991-01-01
The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source terms; environmental transport environmental monitoring data; demographics, agriculture, food habits; environmental pathways and dose estimates.
Hanford Environmental Dose Reconstruction Project
Finch, S.M.; McMakin, A.H.
1992-02-01
The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms; environmental transport; environmental monitoring data; demography, food consumption, and agriculture; environmental pathways and dose estimates.
Modern methods of image reconstruction.
NASA Astrophysics Data System (ADS)
Puetter, R. C.
The author reviews the image restoration or reconstruction problem in its general setting. He first discusses linear methods for solving the problem of image deconvolution, i.e. the case in which the data are a convolution of a point-spread function and an underlying unblurred image. Next, non-linear methods are introduced in the context of Bayesian estimation, including maximum likelihood and maximum entropy methods. Then, the author discusses the role of language and information theory concepts for data compression and solving the inverse problem. The concept of algorithmic information content (AIC) is introduced and is shown to be crucial to achieving optimal data compression and optimized Bayesian priors for image reconstruction. The dependence of the AIC on the selection of language then suggests how efficient coordinate systems for the inverse problem may be selected. The author also introduced pixon-based image restoration and reconstruction methods. The relation between image AIC and the Bayesian incarnation of Occam's Razor is discussed, as well as the relation of multiresolution pixon languages and image fractal dimension. Also discussed is the relation of pixons to the role played by the Heisenberg uncertainty principle in statistical physics and how pixon-based image reconstruction provides a natural extension to the Akaike information criterion for maximum likelihood. The author presents practical applications of pixon-based Bayesian estimation to the restoration of astronomical images. He discusses the effects of noise, effects of finite sampling on resolution, and special problems associated with spatially correlated noise introduced by mosaicing. Comparisons to other methods demonstrate the significant improvements afforded by pixon-based methods and illustrate the science that such performance improvements allow.
Hanford Environmental Dose Reconstruction Project
Cannon, S.D.; Finch, S.M.
1992-10-01
The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The independent Technical Steering Panel (TSP) provides technical direction. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates):Source Terms, Environmental Transport, Environmental Monitoring Data, Demography, Food Consumption, and Agriculture, and Environmental Pathways and Dose Estimates.
Qiu, Man; Zhou, Aiguo; Zhang, Jian; Jiang, Dianming
2016-01-01
A significant cohort of patients is plagued by postoperative rotational instability after the anatomic anterior cruciate ligament (ACL) reconstruction surgery. Anatomic anterolateral ligament (ALL) reconstruction was performed in this study with the aim to assess the clinical role of ALL in knee’s stability and joint functions. Sixty patients were recruited and divided into three groups to perform the operations of anatomic single-bundle ACL reconstruction, anatomic double-bundle ACL reconstruction, and anatomic single-bundle ACL reconstruction + anterolateral ligament reconstruction, respectively. And then postoperative knee’s stability and joint functions were evaluated to compare the clinical outcomes among the three different kind of operations. The postoperative knee’s stability and joint functions of the anatomic double-bundle ACL reconstruction group and the anatomic single-bundle ACL reconstruction + ALL reconstruction group were better than the anatomic single-bundle ACL reconstruction group. No significant difference was observed between the anatomic double-bundle ACL reconstruction group and the anatomic single-bundle ACL reconstruction + ALL reconstruction group. The anatomic anterolateral ligament reconstruction could improve the clinical outcomes after patients performed the anatomic single-bundle anterior cruciate ligament reconstruction. This indicates that the anterolateral ligament plays a crucial role in knee’s stability and joint function, especially the rotational stability. Key points Anatomic anterolateral ligament reconstruction combined with anatomic anterior cruciate ligament reconstruction was performed to treat the patients with ACL rupture. Compared to the anatomic single-bundle ACL reconstruction group, the anatomic single-bundle ACL reconstruction + ALL reconstruction group achieve a better clinical outcomes. The results suggest that the anterolateral ligament plays a crucial role in knee’s stability and joint function
Reconstructing propagation networks with temporal similarity
Liao, Hao; Zeng, An
2015-01-01
Node similarity significantly contributes to the growth of real networks. In this paper, based on the observed epidemic spreading results we apply the node similarity metrics to reconstruct the underlying networks hosting the propagation. We find that the reconstruction accuracy of the similarity metrics is strongly influenced by the infection rate of the spreading process. Moreover, there is a range of infection rate in which the reconstruction accuracy of some similarity metrics drops nearly to zero. To improve the similarity-based reconstruction method, we propose a temporal similarity metric which takes into account the time information of the spreading. The reconstruction results are remarkably improved with the new method. PMID:26086198
Reconstructing propagation networks with temporal similarity.
Liao, Hao; Zeng, An
2015-06-18
Node similarity significantly contributes to the growth of real networks. In this paper, based on the observed epidemic spreading results we apply the node similarity metrics to reconstruct the underlying networks hosting the propagation. We find that the reconstruction accuracy of the similarity metrics is strongly influenced by the infection rate of the spreading process. Moreover, there is a range of infection rate in which the reconstruction accuracy of some similarity metrics drops nearly to zero. To improve the similarity-based reconstruction method, we propose a temporal similarity metric which takes into account the time information of the spreading. The reconstruction results are remarkably improved with the new method.
Reconstruction of chest wall defects.
Hasse, J
1991-12-01
A series of 61 consecutive procedures of chest wall resection and reconstruction in 58 patients during the period between August, 1986 and December, 1990 is reported. The ages ranged between 6-77 years. The chest wall resection was indicated for malignant affections in 54 cases. Among these, there were 24 patients with bronchial carcinoma invading the chest wall, 17 patients with primary or metastatic sarcoma, 11 patients with recurrent breast cancer and 3 with cancer metastases of varying origin. Pulmonary resection included pneumonectomy in 8 cases, lobectomy in 19, segmental and wedge resections in 26. In the majority of resections, the reconstruction was accomplished without implants. In cases with full thickness removal of the chest wall, the plane of the rib cage and/or the sternum was reconstructed using Vicryl mesh (n = 7), PTFE soft tissue patch (n = 11), marlex-mesh (n = 1), or methyl-methacrylate (n = 3). There was one case of hospital mortality, 6 weeks postoperatively, due to neurological failure from an independent preoperatively undiagnosed brain tumor. There were 4 reoperations: one early and one late (4 months) infection, one case of limited superficial necrosis of a flap and one with chronic lymphous drainage from a large myocutaneous flap. In no instance was primary postoperative ventilation therapy necessary. Mechanical ventilation was instituted only on day 8 in the patient who accounts for the mortality in this series. In the presence of primary infection, the greater omentum was used for the restoration of the integument.
Photogrammetric Reconstruction with Bayesian Information
NASA Astrophysics Data System (ADS)
Masiero, A.; Fissore, F.; Guarnieri, A.; Pirotti, F.; Vettore, A.
2016-06-01
Nowadays photogrammetry and laser scanning methods are the most wide spread surveying techniques. Laser scanning methods usually allow to obtain more accurate results with respect to photogrammetry, but their use have some issues, e.g. related to the high cost of the instrumentation and the typical need of high qualified personnel to acquire experimental data on the field. Differently, photogrammetric reconstruction can be achieved by means of low cost devices and by persons without specific training. Furthermore, the recent diffusion of smart devices (e.g. smartphones) embedded with imaging and positioning sensors (i.e. standard camera, GNSS receiver, inertial measurement unit) is opening the possibility of integrating more information in the photogrammetric reconstruction procedure, in order to increase its computational efficiency, its robustness and accuracy. In accordance with the above observations, this paper examines and validates new possibilities for the integration of information provided by the inertial measurement unit (IMU) into the photogrammetric reconstruction procedure, and, to be more specific, into the procedure for solving the feature matching and the bundle adjustment problems.
Interface Reconstruction with Directional Walking
Yao, J
2009-05-22
Young's interface reconstruction with three-dimensional arbitrary mesh, in general, is rather tedious to implement compared to the case of a regular mesh. The main difficulty comes from the construction of a planar facet that bounds a certain volume inside a cell. Unlike the five basic configurations with a Cartesian mesh, there can be a great number of different configurations in the case of a general mesh. We represent a simple method that can derive the topology/geometry of the intersection of arbitrary planar objects in a uniform way. The method is based on a directional walking on the surface of objects, and links the intersection points with the paths of the walking naturally defining the intersection of objects. The method works in both two and three dimensions. The method does not take advantage of convexity, thus decomposition of an object is not necessary. Therefore, the solution with this method will have a reduced number of edges and less data storage, compared with methods that use shape decomposition. The treatment is general for arbitrary polyhedrons, and no look-up tables are needed. The same operation can easily be extended for curved geometry. The implementation of this new algorithm shall allow the interface reconstruction on an arbitrary mesh to be as simple as it is on a regular mesh. Furthermore, we exactly compute the integral of partial cell volume bounded by quadratic interface. Therefore, interface reconstruction with higher than second order accuracy can be achieved on an arbitrary mesh.
Network reconstruction via graph blending
NASA Astrophysics Data System (ADS)
Estrada, Rolando
2016-05-01
Graphs estimated from empirical data are often noisy and incomplete due to the difficulty of faithfully observing all the components (nodes and edges) of the true graph. This problem is particularly acute for large networks where the number of components may far exceed available surveillance capabilities. Errors in the observed graph can render subsequent analyses invalid, so it is vital to develop robust methods that can minimize these observational errors. Errors in the observed graph may include missing and spurious components, as well fused (multiple nodes are merged into one) and split (a single node is misinterpreted as many) nodes. Traditional graph reconstruction methods are only able to identify missing or spurious components (primarily edges, and to a lesser degree nodes), so we developed a novel graph blending framework that allows us to cast the full estimation problem as a simple edge addition/deletion problem. Armed with this framework, we systematically investigate the viability of various topological graph features, such as the degree distribution or the clustering coefficients, and existing graph reconstruction methods for tackling the full estimation problem. Our experimental results suggest that incorporating any topological feature as a source of information actually hinders reconstruction accuracy. We provide a theoretical analysis of this phenomenon and suggest several avenues for improving this estimation problem.
Environment reconstruction for robot navigation
NASA Astrophysics Data System (ADS)
Bohn, Shawn J.; Thornton, Erin N.
1994-07-01
The United States Department of Energy is facing a large task in characterizing and remediating waste tanks and their contents. Because of the hazardous materials inside the waste tanks, all of the work must be done remotely. The purpose of this paper is to show how to reconstruct an enclosed environment from various scans of a Laser Range Finder. The reconstructed environment can then be used by a robot for path planning, and by an operator to monitor the progress of the waste remediation process. Environment reconstruction consists of two tasks: image processing and laser sculpting. The image processing task focuses first on reducing the quantity of low-confidence data and on smoothing random fluctuations in the data. Then the processed range data must be converted into an XYZ Cartesian coordinate space, a process for which we examined two methods. The first method is a geometrical transform of the LRF data. The second uses an artificial neural network to transform the data to XYZ coordinates. Once an XYZ data set is computed, laser sculpting can be performed. Laser sculpting employs a hierarchical tree structure formally called an octree. The octree structure allows efficient storage of volumetric data and the ability to fuse multiple data sets. Our research has allowed us to examine the difficulties of fusing multiple LRF scans into an octree and to develop algorithms for converting an octree structure into a representation of polygon surfaces.
Environment reconstruction for robot navigation
Bohn, S.; Thornton, E.
1994-04-01
The United State Department of Energy (DOE) is facing a large task in characterizing and remediating waste tanks and their contents. Because of the hazardous materials inside the waste tanks, all of the work must be done remotely. The purpose of this paper is to show how to reconstruct an enclosed environment from various scans of a Laser Range Finder (LRF). The reconstructed environment can then be used by a robot for path planning, and by an operator to monitor the progress of the waste remediation process. Environment reconstruction consists of two tasks: image processing and laser sculpting. The image processing task focuses first on reducing the quantity of low-confidence data and on smoothing random fluctuations in the data. Then the processed range data must be converted into an XYZ Cartesian coordinate space, a process for which we examined two methods. The first method is a geometrical transform of the LRF data. The second uses an artificial neural network to transform the data to XYZ coordinates. Once an XYZ data set is computed, laser sculpting can be performed. Laser sculpting employs a hierarchical tree structure formally called an octree. The octree structure allows efficient storage of volumetric data and the ability to fuse multiple data sets. Our research has allowed us to examine the difficulties of fusing multiple LRF scans into an octree and to develop algorithms for converting an octree structure into a representation of polygon surfaces.
On the search of optimal reconstruction resolution
Vuçini, Erald; Kropatsch, Walter G.
2012-01-01
In this paper we present a novel algorithm to optimize the reconstruction from non-uniform point sets. We introduce a statistically-derived topology-controller for selecting the reconstruction resolution of a given non-uniform point set. Deriving information from homology-based statistics, our topology-controller ensures a stable and sound basis for the analysis process. By analyzing our topology-controller, we select an optimal reconstruction resolution which ensures both low reconstruction errors and a topological stability of the underlying signal. Our approach offers a valuable method for the evaluation of the reconstruction process without the need of visual inspection of the reconstructed datasets. By means of qualitative results we show how our proposed topology statistics provides complementary information in the enhancement of existing reconstruction pipelines in visualization. PMID:22865947
MER EDL: Overview and Reconstruction Status
NASA Technical Reports Server (NTRS)
Desai, Prasun N.; Lee, Wayne J.
2005-01-01
An overview and reconstruction of the Mars Exploration Rover (MER) Entry Descent and Landing (EDL) is shown. The topics include: 1) Background; 2) MER Candidate Landing Sites; 3) MER Entry Heritage w/Viking & Mars Pathfinder; 4) MER EDL Animation; 5) MER Entry, Descent, and Landing (EDL) Sequence; 6) Pre-Entry Spirit Entry Atmosphere Models; 7) Spirit Landing Ellipse at Final OD, & Updated Estimate Differenced 1-way Doppler; 8) Spirit Landing Ellipse at Final OD and Final Location Estimates; 9) Monte Carlo Results for Spirit ; 10) Reconstructed and refined Spirit Entry Density Profile; 11) Mars Pathfinder Attitude Reconstruction; 12) Spirit Attitude Reconstruction; 13) Spirit Entry Ground Track; 14) Reconstructed Spirit Terminal Descent Dynamics (Side View); 15) Opportunity Landing Ellipse at Final OD, & Updated Estimate Differenced 1-way Doppler; 16) Spirit Landing Ellipse at Final OD and Final Location Estimates; 17) Monte Carlo Results for Opportunity; 18) Reconstructed Opportunity Entry Density Profile; and 19) Opportunity Attitude Reconstruction.
Revisiting the Least-squares Procedure for Gradient Reconstruction on Unstructured Meshes
NASA Technical Reports Server (NTRS)
Mavriplis, Dimitri J.; Thomas, James L. (Technical Monitor)
2003-01-01
The accuracy of the least-squares technique for gradient reconstruction on unstructured meshes is examined. While least-squares techniques produce accurate results on arbitrary isotropic unstructured meshes, serious difficulties exist for highly stretched meshes in the presence of surface curvature. In these situations, gradients are typically under-estimated by up to an order of magnitude. For vertex-based discretizations on triangular and quadrilateral meshes, and cell-centered discretizations on quadrilateral meshes, accuracy can be recovered using an inverse distance weighting in the least-squares construction. For cell-centered discretizations on triangles, both the unweighted and weighted least-squares constructions fail to provide suitable gradient estimates for highly stretched curved meshes. Good overall flow solution accuracy can be retained in spite of poor gradient estimates, due to the presence of flow alignment in exactly the same regions where the poor gradient accuracy is observed. However, the use of entropy fixes has the potential for generating large but subtle discretization errors.
Structural reliability of road accidents reconstruction.
Wach, Wojciech
2013-05-10
Reconstruction of road accidents combines objective and subjective action. The former concerns science, the latter assessment of human behavior in the context of objective findings. It is not uncommon for experts equipped with an arsenal of tools to obtain similar results of calculations, but to present radically different conclusions about the cause of the accident. The use of sophisticated methods of uncertainty analysis does not guarantee improvement in quality of reconstruction, because, increasingly, the most serious source of reduced reliability of reconstruction is problems in logical inference. In the article the structure of uncertainty and reliability of accident reconstruction was described. A definition of reliability of road accident reconstruction based on the theory of conditional probability and Bayesian network, as a function of modeling, data and expert reliability (defined in the text) was proposed. The uncertainty of reconstruction was made dependent only on the uncertainty of the data. This separation makes it possible to conduct a qualitative and quantitative analysis of reconstruction reliability and to analyze its sensitivity to component parameters, independently of the uncertainty analysis. An example of calculation was presented. The proposed formalism constitutes a tool helpful to explain, among other things, the paradox of reliable reconstruction despite its uncertain results or unreliable reconstruction despite high precision of results. This approach is of great importance in the reconstruction of road accidents, which goes far beyond the analysis of a single, homogeneous subsystem.
Reconstruction of Anacostia wetlands: success?
Hammerschlag, R.S.; Perry, M.C.
2002-01-01
Historically, the tidal Anacostia River in Washington, D.C. had been an extensive system of freshwater tidal marshes replete with a full array of wetland vegetation dominated by wild rice. The local Nacochtank Indians had found the abundant fish and wildlife sufficient to sustain their daily lives. White man's intrusion upon the landscape gradually brought about deterioration of the natural (and associated cultural) system. Total demise followed mid-20th century dredge and fill channelization, which was conducted from the confluence of the Anacostia with the Potomac near the heart of Washington, D.C. to the terminus of the tidal regime at Bladensburg, Maryland. The National Park Service (NPS) became the manager for much of the land along the Anacostia, particularly the eastern bank. As part of its planning effort, the NPS envisioned returning portions of the Anacostia under its control to a natural system as a vignette. The concept was based on bringing back as comprehensive a collection of vegetation and wildlife as possible through the reestablishment of tidal marshes at Kenilworth and Kingman. The resultant wetlands were to be made accessible to the public both logistically and through a well designed interpretative program. In fact, this vision has been realized due to an impressive cooperative effort among a number of Federal and local agencies and organizations. In 1993, 32 acres of freshwater tidal marsh were reconstructed at Kenilworth. Based upon the 5-year monitoring program that has been in place since reconstruction, several generalizations may be made concerning the degree of success of the marsh reconstruction. Water quality in the marsh system and nearby tidal waters has not been noticeably improved. The poor quality may be clue to the overwhelmingly high loads (e.g., sediment, nutrients, etc.) brought in on the twice daily tidal cycle from the Anacostia and to the relatively small volume of water which actually interacts with the emergent marsh
Recovery after abdominal wall reconstruction.
Jensen, Kristian Kiim
2017-03-01
Incisional hernia is a common long-term complication to abdominal surgery, occurring in more than 20% of all patients. Some of these hernias become giant and affect patients in several ways. This patient group often experiences pain, decreased perceived body image, and loss of physical function, which results in a need for surgical repair of the giant hernia, known as abdominal wall reconstruction. In the current thesis, patients with a giant hernia were examined to achieve a better understanding of their physical and psychological function before and after abdominal wall reconstruction. Study I was a systematic review of the existing standardized methods for assessing quality of life after incisional hernia repair. After a systematic search in the electronic databases Embase and PubMed, a total of 26 studies using standardized measures for assessment of quality of life after incisional hernia repair were found. The most commonly used questionnaire was the generic Short-Form 36, which assesses overall health-related quality of life, addressing both physical and mental health. The second-most common questionnaire was the Carolinas Comfort Scale, which is a disease specific questionnaire addressing pain, movement limitation and mesh sensation in relation to a current or previous hernia. In total, eight different questionnaires were used at varying time points in the 26 studies. In conclusion, standardization of timing and method of quality of life assessment after incisional hernia repair was lacking. Study II was a case-control study of the effects of an enhanced recovery after surgery pathway for patients undergoing abdominal wall reconstruction for a giant hernia. Sixteen consecutive patients were included prospectively after the implementation of a new enhanced recovery after surgery pathway at the Digestive Disease Center, Bispebjerg Hospital, and compared to a control group of 16 patients included retrospectively in the period immediately prior to the
Rolling Contact Force Energy Reconstruction
NASA Astrophysics Data System (ADS)
BRACCIALI, A.; CASCINI, G.
2000-09-01
Knowledge of the forces at the wheel-rail contact is fundamental to estimate the consequences in terms of noise and vibration. The traditional use of strain gauges mounted on the wheel web and axle is not capable of determining the high-frequency content of the contact force. Measurements made on the rail are characterized by the spatial variability of input-output transfer functions which makes it difficult to estimate the contact force by simple inversion of the point frequency response function. In this study the problem of rolling contact force reconstruction has been approached through the following steps: (i) the track has been characterized precisely for a finite length by the analysis of the time series of several impacts supplied with an instrumented hammer by using an ARMAX model that proved to be capable of modelling the vertical dynamics of the rail up to 5 kHz; (ii) the response of the rail has been simulated with a random force acting on the system, and the variability of the transfer function has been taken into account by distributing the force on adjacent elements; (iii) the simulated response has been compared with the rail acceleration measured for the passage of several trains; (iv) the wheel-rail contact force has been estimated with a closed-loop algorithm. It has thus been possible to reconstruct the13octave power spectrum of contact forces with a simple and stable iterative procedure. Forces reconstructed from different sensors were found to be practically the same for a given wheel; forces from nominally similar wheels are statistically examined and partial results of comparisons made on different rolling stock are shown.
Economics of abdominal wall reconstruction.
Bower, Curtis; Roth, J Scott
2013-10-01
The economic aspects of abdominal wall reconstruction are frequently overlooked, although understandings of the financial implications are essential in providing cost-efficient health care. Ventral hernia repairs are frequently performed surgical procedures with significant economic ramifications for employers, insurers, providers, and patients because of the volume of procedures, complication rates, the significant rate of recurrence, and escalating costs. Because biological mesh materials add significant expense to the costs of treating complex abdominal wall hernias, the role of such costly materials needs to be better defined to ensure the most cost-efficient and effective treatments for ventral abdominal wall hernias.
Reconstruction of fundamental SUSY parameters
P. M. Zerwas et al.
2003-09-25
We summarize methods and expected accuracies in determining the basic low-energy SUSY parameters from experiments at future e{sup +}e{sup -} linear colliders in the TeV energy range, combined with results from LHC. In a second step we demonstrate how, based on this set of parameters, the fundamental supersymmetric theory can be reconstructed at high scales near the grand unification or Planck scale. These analyses have been carried out for minimal supergravity [confronted with GMSB for comparison], and for a string effective theory.
Review of jet reconstruction algorithms
NASA Astrophysics Data System (ADS)
Atkin, Ryan
2015-10-01
Accurate jet reconstruction is necessary for understanding the link between the unobserved partons and the jets of observed collimated colourless particles the partons hadronise into. Understanding this link sheds light on the properties of these partons. A review of various common jet algorithms is presented, namely the Kt, Anti-Kt, Cambridge/Aachen, Iterative cones and the SIScone, highlighting their strengths and weaknesses. If one is interested in studying jets, the Anti-Kt algorithm is the best choice, however if ones interest is in the jet substructures then the Cambridge/Aachen algorithm would be the best option.
Hanford Environmental Dose Reconstruction Project
Finch, S.M.; McMakin, A.H.
1992-06-01
The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is being managed and conducted by the Battelle Pacific Northwest Laboratories under contract with the Centers for Disease Control. The independent Technical Steering Panel (TSP) provides technical direction. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms; environmental transport; environmental monitoring data; demography, food consumption, and agriculture; environmental pathways and dose estimates.
Reconstruction of the rheumatoid thumb.
Rozental, Tamara D
2007-02-01
Thumb deformities are common manifestations of rheumatoid arthritis and represent a significant source of disability. A clear understanding of the pathophysiology of the disease is essential in directing treatment. Differential diagnosis for flexible deformities includes soft-tissue imbalances as well as tendon ruptures. In its early stages, thumb involvement can be treated nonsurgically or with soft-tissue reconstruction. With more advanced disease, arthrodesis and arthroplasty often are required. Isolated interphalangeal involvement is best addressed with arthrodesis. Metacarpophalangeal involvement can be treated with arthroplasty in low-demand patients or with arthrodesis in more active patients. Trapezium resection arthroplasty provides excellent relief for patients with carpometacarpal joint destruction.
Method for position emission mammography image reconstruction
Smith, Mark Frederick
2004-10-12
An image reconstruction method comprising accepting coincidence datat from either a data file or in real time from a pair of detector heads, culling event data that is outside a desired energy range, optionally saving the desired data for each detector position or for each pair of detector pixels on the two detector heads, and then reconstructing the image either by backprojection image reconstruction or by iterative image reconstruction. In the backprojection image reconstruction mode, rays are traced between centers of lines of response (LOR's), counts are then either allocated by nearest pixel interpolation or allocated by an overlap method and then corrected for geometric effects and attenuation and the data file updated. If the iterative image reconstruction option is selected, one implementation is to compute a grid Siddon retracing, and to perform maximum likelihood expectation maiximization (MLEM) computed by either: a) tracing parallel rays between subpixels on opposite detector heads; or b) tracing rays between randomized endpoint locations on opposite detector heads.
Provisional Reconstruction Teams: An Operational Imperative
2007-11-06
Quarterly: Winter 2005-06 p. 45 17 Mark Sedra , “Civil-Military Relations in Afghanistan: the Provincial Reconstruction Team Debate,” Policy...Transformation, Parameters, Winter 2005-06, p. 1 27 Mark Sedra , “Civil-Military Relations in Afghanistan: the Provincial Reconstruction Team Debate,” Policy...the Children, Provincial Reconstruction Teams and Humanitarian–Military Relations in Afghanistan, 1 St John’s Lane London EC1M 4AR UK, 2004 Sedra
On Solar Cycle Predictions and Reconstructions
2008-12-01
for grand solar minima and to reconstruct the relative sunspol number in the Maunder minimum . Methods. We calculate the asymmetry of the ascending...was identified in the asymmetry data. The maximal smoothed monthly sunspot number during the Maunder minimum was reconstructed and found to be in the...cycle, to investigate proxies for grand solar minima and to reconstruct the relative sunspot number in the Maunder minimum . Methods. We calculate the
Reconstruction of middle ear malformations
Schwager, Konrad
2008-01-01
Malformations of the middle ear are classified as minor and major malformations. Minor malformations appear with regular external auditory canal, tympanic membrane and aerated middle ear space. The conducting hearing loss is due to fixation or interruption of the ossicular chain. The treatment is surgical, following the rules of ossiculoplasty and stapes surgery. In major malformations (congenital aural atresia) there is no external auditory canal and a deformed or missing pinna. The mastoid and the middle ear space may be underdevelopped, the ossicular chain is dysplastic. Surgical therapy is possible in patients with good aeration of the temporal bone, existing windows, a near normal positioned facial nerve and a mobile ossicular chain. Plastic and reconstructive surgery of the pinna should proceed the reconstruction of the external auditory canal and middle ear. In cases of good prognosis unilateral aural atresia can be approached already in childhood. In patients with high risk of surgical failure, bone anchored hearing aids are the treatment of choice. Recent reports of implantable hearing devices may be discussed as an alternative treatment for selected patients. PMID:22073077
Hanford Environmental Dose Reconstruction Project
Finch, S.M.
1990-01-01
The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that populations could have received from nuclear operations at Hanford since 1944. The project is being managed and conducted by the Pacific Northwest Laboratory (PNL) under the direction of an independent Technical Steering Panel (TSP). The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates). The Source Terms Task develops estimates of radioactive emissions from Hanford facilities since 1944. The Environmental Transport Task reconstructs the movement of radioactive materials from the areas of release to populations. The Environmental Monitoring Data Task assembles, evaluates, and reports historical environmental monitoring data. The Demographics, Agriculture, Food Habits Task develops the data needed to identify the populations that could have been affected by the releases. In addition to population and demographic data, the food and water resources and consumption patterns for populations are estimated because they provide a primary pathway for the intake of radionuclides. The Environmental Pathways and Dose Estimates Task use the information produced by the other tasks to estimate the radiation doses populations could have received from Hanford radiation. Project progress is documented in this monthly report, which is available to the public. 3 figs., 3 tabs.
Geometric effects in tomographic reconstruction
Barnes, F.L.; Azevedo, S.G.; Martz, H.E. Jr.; Roberson, G.P.; Schneberk, D.J.; Skeate, M.F.
1990-01-08
In x-ray and ion-beam computerized tomography, there are a number of reconstruction effects, manifested as artifacts, that can be attributed to the geometry of the experimental setup and of the object being scanned. In this work, we will examine four geometric effects that are common to first-and third-generation (parallel beam, 180 degree) computerized tomography (CT) scanners and suggest solutions for each problem. The geometric effects focused on in this paper are: X-pattern'' artifacts (believed to be caused by several errors), edge-generated ringing artifacts (due to improper choice of the reconstruction filter and cutoff frequency), circular-ring artifacts (caused by employing uncalibrated detectors), and tuning-fork artifacts (generated by an incorrectly specified center-of-rotation). Examples of four effects are presented. The X-pattern and edge-generated ringing artifacts are presented with actual experimental data introducing the artifact. given the source of the artifact, we present simulated data designed to replicate the artifact. Finally, we suggest ways to reduce or completely remove these artifacts. The circular-ring and tuning-fork artifacts are introduced with actual experimental data as well, while digital signal processing solutions are employed to remove the artifacts from the data. 15 refs., 12 figs.
Hanford Environmental Dose Reconstruction Project
Finch, S. M.; McMakin, A. H.
1991-09-01
The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation dose that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into five technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (i.e., dose estimates). The Source Terms Task develops estimates of radioactive emissions from Hanford facilities since 1944. The Environmental Transport Task reconstructs the movements of radioactive particles from the areas of release to populations. The Environmental Monitoring Data Task assemblies, evaluates and reports historical environmental monitoring data. The Demographics, Agriculture and Food Habits Task develops the data needed to identify the populations that could have been affected by the releases. The Environmental Pathways and Dose Estimates Task used the information derived from the other Tasks to estimate the radiation doses individuals could have received from Hanford radiation. This document lists the progress on this project as of September 1991. 3 figs., 2 tabs.
Applications of genome-scale metabolic reconstructions
Oberhardt, Matthew A; Palsson, Bernhard Ø; Papin, Jason A
2009-01-01
The availability and utility of genome-scale metabolic reconstructions have exploded since the first genome-scale reconstruction was published a decade ago. Reconstructions have now been built for a wide variety of organisms, and have been used toward five major ends: (1) contextualization of high-throughput data, (2) guidance of metabolic engineering, (3) directing hypothesis-driven discovery, (4) interrogation of multi-species relationships, and (5) network property discovery. In this review, we examine the many uses and future directions of genome-scale metabolic reconstructions, and we highlight trends and opportunities in the field that will make the greatest impact on many fields of biology. PMID:19888215
Reconstruction of congenital defects of the vagina.
Eldor, Liron; Friedman, Jeffrey D
2011-05-01
Congenital absence of the vagina is a relatively rare condition most commonly associated with Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome. Historically, several reconstructive techniques have been described to provide for functional vaginal reconstruction on these patients, both operative and nonoperative. Although there are many advantages and disadvantages of the various procedures, one experience with the use of split thickness skin grafts to reconstruct the vagina has produced acceptable functional results with limited donor site morbidity. Careful planning and timing of this form of reconstruction can produce predictable results in patients who are nearing sexual maturity.
Shoulder acromioclavicular joint reconstruction options and outcomes.
Lee, Simon; Bedi, Asheesh
2016-12-01
Acromioclavicular joint separations are a common cause of shoulder pain in the young athletic population. In high-grade injuries, acromioclavicular joint reconstruction procedures may be indicated for functional improvement. There is currently no gold standard for the surgical management of these injuries. Multiple reconstructive options exist, including coracoclavicular screws, hook plates, endobutton coracoclavicular fixations, and anatomic ligament reconstructions with tendon grafts. This article aims to review pertinent acromioclavicular joint anatomy and biomechanics, radiographic evaluation, classification system, as well as reconstruction options, outcomes, and complications.
Milestones in the History of Ear Reconstruction.
Berghaus, Alexander; Nicoló, Marion San
2015-12-01
The reconstruction of ear deformities has been challenging plastic surgeons since centuries. However, it is only in the 19th century that reports on partial and total ear reconstruction start increasing. In the quest for an aesthetically pleasing and natural-looking result, surgeons worked on the perfect framework and skin coverage. Different materials and flap techniques have evolved. Some were abandoned out of frustration, while others kept evolving over the years. In this article, we discuss the milestones in ear reconstruction-from ancient times to early attempts in Western civilization to the key chapters of ear reconstruction in the 20th century leading to the current techniques.
40 CFR 60.706 - Reconstruction.
Code of Federal Regulations, 2010 CFR
2010-07-01
... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Volatile Organic Compound Emissions From Synthetic Organic Chemical Manufacturing Industry (SOCMI) Reactor Processes § 60.706 Reconstruction. (a)...
Da Ronco, Saverio
2006-01-01
This thesis reports the reconstruction and lifetime measurement of B^{+}, B$0/atop{d}$ and B$0/atop{s}$ mesons, performed using fully reconstructed hadronic decays collected by a dedicated trigger at CDF II experiment. This dedicated trigger selects significantly displaced tracks from primary vertex of p$\\bar{p}$ collisions generated at Tevatron collider, obtaining, in this way, huge data samples enriched of long-lived particles, and is therefore suitable for reconstruction of B meson in hadronic decay modes. Due to the trigger track impact parameter selections, the proper decay time distributions of the B mesons no longer follow a simply exponential decay law. This complicates the lifetime measurement and requires a correct understanding and treatment of all the involved effects to keep systematic uncertainties under control. This thesis presents a method to extract the lifetime of B mesons in “ct- biased” samples, based on a Monte Carlo approach, to correct for the effects of the trigger and analysis selections. We present the results of this method when applied on fully re- constructed decays of B collected by CDF II in the data taking runs up to August 2004, corresponding to an integrated luminosity of about 360 pb^{-1}. The lifetimes are extracted using the decay modes B^{+} → $\\bar{D}$^{0}π^{+},B$0\\atop{d}$ → D^{-}π^{+}, B$0\\atop{d}$ → D^{-}π^{+}π^{-}π^{+}, B$0\\atop{s}$ → D$-\\atop{s}$π^{+} and B$0\\atop{s}$ → D$-\\atop{s}$ π^{+}π^{-}π^{+}(and c.c.) and performing combined mass-lifetime unbinned maximum likelihood fits.
Rational approximations for tomographic reconstructions
NASA Astrophysics Data System (ADS)
Reynolds, Matthew; Beylkin, Gregory; Monzón, Lucas
2013-06-01
We use optimal rational approximations of projection data collected in x-ray tomography to improve image resolution. Under the assumption that the object of interest is described by functions with jump discontinuities, for each projection we construct its rational approximation with a small (near optimal) number of terms for a given accuracy threshold. This allows us to augment the measured data, i.e., double the number of available samples in each projection or, equivalently, extend (double) the domain of their Fourier transform. We also develop a new, fast, polar coordinate Fourier domain algorithm which uses our nonlinear approximation of projection data in a natural way. Using augmented projections of the Shepp-Logan phantom, we provide a comparison between the new algorithm and the standard filtered back-projection algorithm. We demonstrate that the reconstructed image has improved resolution without additional artifacts near sharp transitions in the image.
Reconstructing and deconstructing dark energy
Linder, Eric V.
2004-06-07
The acceleration of the expansion of the universe, ascribed to a dark energy, is one of the most intriguing discoveries in science. In addition to precise, systematics controlled data, clear, robust interpretation of the observations is required to reveal the nature of dark energy. Even for the simplest question: is the data consistent with the cosmological constant? there are important subtleties in the reconstruction of the dark energy properties. We discuss the roles of analysis both in terms of the Hubble expansion rate or dark energy density {rho}DE(z) and in terms of the dark energy equation of state w(z), arguing that each has its carefully defined place. Fitting the density is best for learning about the density, but using it to probe the equation of state can lead to instability and bias.
Hanford Environmental Dose Reconstruction Project
McMakin, A.H.; Cannon, S.D.; Finch, S.M.
1992-07-01
The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The TSP consists of experts in environmental pathways, epidemiology, surface-water transport, ground-water transport, statistics, demography, agriculture, meteorology, nuclear engineering, radiation dosimetry, and cultural anthropology. Included are appointed technical members representing the states of Oregon, Washington, and Idaho, a representative of Native American tribes, and an individual representing the public. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates): Source terms, environmental transport, environmental monitoring data, demography, food consumption, and agriculture, and environmental pathways and dose estimates. Progress is discussed.
Hanford Environmental Dose Reconstruction Project
Finch, S.M.; McMakin, A.H.
1991-01-01
The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is being managed and conducted by the Pacific Northwest Laboratory (PNL) under the direction of an independent Technical Steering Panel (TSP). The TSP consists of experts in environmental pathways, epidemiology, surface-water transport, ground-water transport, statistics, demography, agriculture, meteorology, nuclear engineering, radiation dosimetry, and cultural anthropology. Included are appointed technical members representing the states of Oregon and Washington, a representative of Native American tribes, and an individual representing the public. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on human (dose estimates): Source Terms; Environmental Transport; Environmental Monitoring Data; Demographics, Agriculture, Food Habits and; Environmental Pathways and Dose Estimates.
Reconstruction of nonlinear wave propagation
Fleischer, Jason W; Barsi, Christopher; Wan, Wenjie
2013-04-23
Disclosed are systems and methods for characterizing a nonlinear propagation environment by numerically propagating a measured output waveform resulting from a known input waveform. The numerical propagation reconstructs the input waveform, and in the process, the nonlinear environment is characterized. In certain embodiments, knowledge of the characterized nonlinear environment facilitates determination of an unknown input based on a measured output. Similarly, knowledge of the characterized nonlinear environment also facilitates formation of a desired output based on a configurable input. In both situations, the input thus characterized and the output thus obtained include features that would normally be lost in linear propagations. Such features can include evanescent waves and peripheral waves, such that an image thus obtained are inherently wide-angle, farfield form of microscopy.
[Surgical reconstruction of joint function].
Ishikawa, Hajime
2013-07-01
In recent years a concept of "treat to target" is introduced into a medical treatment of RA, and tight control is recommended from the early stage of the disease. However, it is difficult to relieve all patients in a true remission. Nowadays, disease activity is controlled well and a reconstructive surgery is performed at a limited number of the damaged joints in a state of good remaining of bone and soft tissue structures. The patients are highly motivated, and a newly developed disorder at the non-surgically treated joints is uncommon. Therefore, an aggressive rehabilitation is possible. Combined with a medical treatment of RA, a surgical intervention enables to acquire a higher level of ADL and an improved QOL (Japanese T2T).
Uţă, M M; Cioloboc, D; King, R B
2012-09-13
One of the most significant recent developments (in 2009) is the discovery of the clusters M@Ge10(3-) (M = Fe, Co) in which the outer Ge10 polyhedron is a pentagonal prism rather than a deltahedral structure of the type predicted by the Wade-Mingos rules. Consistent with this experimental observation, density functional theory shows the lowest energy structures to be pentagonal prisms for the iron-centered clusters Fe@Ge10(z) in all nine charge states ranging from -5 to +3. This contrasts with the previously studied cobalt-centered germanium clusters Co@Ge10(z) for which the lowest energy structures are pentagonal prisms only for the electron richest systems where z ranges from -3 to -5. The C3v structures derived from the tetracapped trigonal prism found as lowest energy structures of the electron poorer Co@Ge10(z) (z = 0, -1, -2) systems are higher energy structures for the iron-centered germanium clusters Fe@Ge10(z) (z = 0, -1, -2). The strong energetic preference for pentagonal prismatic structures in the Fe@Ge10(z) clusters can be attributed to the need for the larger volume of the pentagonal prism relative to other 10-vertex closed polyhedra to accommodate the interstitial iron atom.
Image reconstruction in optical tomography.
Arridge, S R; Schweiger, M
1997-01-01
Optical tomography is a new medical imaging modality that is at the threshold of realization. A large amount of clinical work has shown the very real benefits that such a method could provide. At the same time a considerable effort has been put into theoretical studies of its probable success. At present there exist gaps between these two realms. In this paper we review some general approaches to inverse problems to set the context for optical tomography, defining both the terms forward problem and inverse problem. An essential requirement is to treat the problem in a nonlinear fashion, by using an iterative method. This in turn requires a convenient method of evaluating the forward problem, and its derivatives and variance. Photon transport models are described for obtaining analytical and numerical solutions for the most commonly used ones are reviewed. The inverse problem is approached by classical gradient-based solution methods. In order to develop practical implementations of these methods, we discuss the important topic of photon measurement density functions, which represent the derivative of the forward problem. We show some results that represent the most complex and realistic simulations of optical tomography yet developed. We suggest, in particular, that both time-resolved, and intensity-modulated systems can reconstruct variations in both optical absorption and scattering, but that unmodulated, non-time-resolved systems are prone to severe artefact. We believe that optical tomography reconstruction methods can now be reliably applied to a wide variety of real clinical data. The expected resolution of the method is poor, meaning that it is unlikely that the type of high-resolution images seen in computed tomography or medical resonance imaging can ever be obtained. Nevertheless we strongly expect the functional nature of these images to have a high degree of clinical significance. PMID:9232860
Parallel Reconstruction Using Null Operations (PRUNO)
Zhang, Jian; Liu, Chunlei; Moseley, Michael E.
2011-01-01
A novel iterative k-space data-driven technique, namely Parallel Reconstruction Using Null Operations (PRUNO), is presented for parallel imaging reconstruction. In PRUNO, both data calibration and image reconstruction are formulated into linear algebra problems based on a generalized system model. An optimal data calibration strategy is demonstrated by using Singular Value Decomposition (SVD). And an iterative conjugate- gradient approach is proposed to efficiently solve missing k-space samples during reconstruction. With its generalized formulation and precise mathematical model, PRUNO reconstruction yields good accuracy, flexibility, stability. Both computer simulation and in vivo studies have shown that PRUNO produces much better reconstruction quality than autocalibrating partially parallel acquisition (GRAPPA), especially under high accelerating rates. With the aid of PRUO reconstruction, ultra high accelerating parallel imaging can be performed with decent image quality. For example, we have done successful PRUNO reconstruction at a reduction factor of 6 (effective factor of 4.44) with 8 coils and only a few autocalibration signal (ACS) lines. PMID:21604290
Some Factors Affecting Time Reversal Signal Reconstruction
NASA Astrophysics Data System (ADS)
Prevorovsky, Z.; Kober, J.
Time reversal (TR) ultrasonic signal processing is now broadly used in a variety of applications, and also in NDE/NDT field. TR processing is used e.g. for S/N ratio enhancement, reciprocal transducer calibration, location, identification, and reconstruction of unknown sources, etc. TR procedure in con-junction with nonlinear elastic wave spectroscopy NEWS is also useful for sensitive detection of defects (nonlinearity presence). To enlarge possibilities of acoustic emission (AE) method, we proposed the use of TR signal reconstruction ability for detected AE signals transfer from a structure with AE source onto a similar remote model of the structure (real or numerical), which allows easier source analysis under laboratory conditions. Though the TR signal reconstruction is robust regarding the system variations, some small differences and changes influence space-time TR focus and reconstruction quality. Experiments were performed on metallic parts of both simple and complicated geometry to examine effects of small changes of temperature or configuration (body shape, dimensions, transducers placement, etc.) on TR reconstruction quality. Results of experiments are discussed in this paper. Considering mathematical similarity between TR and Coda Wave Interferometry (CWI), prediction of signal reconstruction quality was possible using only the direct propagation. The results show how some factors like temperature or stress changes may deteriorate the TR reconstruction quality. It is also shown that sometimes the reconstruction quality is not enhanced using longer TR signal (S/N ratio may decrease).
Special Inspector General for Iraq Reconstruction
2009-04-30
Economy 96 Section 3 Reconstruction by Province 105 Provincial Elections 106 Provincial Reconstruction Teams 112 Provincial Snapshots 114 Kurdistan 116...provincial investment commis- sions to assist in the registration and support of foreign and domestic investors. Kurdistan , however, maintains its...quarter between the GOI and Kurdistan Regional Government (KRG). In northern and central Iraq, Kurdish pressure on the GOI to implement Article 140
17 CFR 37.406 - Trade reconstruction.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 17 Commodity and Securities Exchanges 1 2014-04-01 2014-04-01 false Trade reconstruction. 37.406 Section 37.406 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION SWAP EXECUTION FACILITIES Monitoring of Trading and Trade Processing § 37.406 Trade reconstruction. The swap...
Anterior cruciate ligament reconstruction and knee osteoarthritis
Paschos, Nikolaos K
2017-01-01
Anterior cruciate ligament (ACL) injury is a traumatic event that can lead to significant functional impairment and inability to participate in high-level sports-related activities. ACL reconstruction is considered the treatment of choice for symptomatic ACL-deficient patients and can assist in full functional recovery. Furthermore, ACL reconstruction restores ligamentous stability to normal, and, therefore, can potentially fully reinstate kinematics of the knee joint. As a consequence, the natural history of ACL injury could be potentially reversed via ACL reconstruction. Evidence from the literature is controversial regarding the effectiveness of ACL reconstruction in preventing the development of knee cartilage degeneration. This editorial aims to present recent high-level evidence in an attempt to answer whether ACL injury inevitably leads to osteoarthritis and whether ACL reconstruction can prevent this development or not. PMID:28361013
Innovations in diabetic foot reconstruction using supermicrosurgery.
Suh, Hyun Suk; Oh, Tae Suk; Hong, Joon Pio
2016-01-01
The treatment of diabetic foot ulceration is complex with multiple factors involved, and it may often lead to limb amputation. Hence, a multidisciplinary approach is warranted to cover the spectrum of treatment for diabetic foot, but in complex wounds, surgical treatment is inevitable. Surgery may involve the decision to preserve the limb by reconstruction or to amputate it. Reconstruction involves preserving the limb with secure coverage. Local flaps usually are able to provide sufficient coverage for small or moderate sized wound, but for larger wounds, soft tissue coverage involves flaps that are distantly located from the wound. Reconstruction of distant flap usually involves microsurgery, and now, further innovative methods such as supermicrosurgery have further given complex wounds a better chance to be reconstructed and limbs salvaged. This article reviews the microsurgery involved in reconstruction and introduces the new method of supermicrosurgery.
Virtual Surgical Planning for Orbital Reconstruction
Susarla, Srinivas M.; Duncan, Katherine; Mahoney, Nicholas R.; Merbs, Shannath L.; Grant, Michael P.
2015-01-01
The advent of computer-assisted technology has revolutionized planning for complex craniofacial operations, including orbital reconstruction. Orbital reconstruction is ideally suited for virtual planning, as it allows the surgeon to assess the bony anatomy and critical neurovascular structures within the orbit, and plan osteotomies, fracture reductions, and orbital implant placement with efficiency and predictability. In this article, we review the use of virtual surgical planning for orbital decompression, posttraumatic midface reconstruction, reconstruction of a two-wall orbital defect, and reconstruction of a large orbital floor defect with a custom implant. The surgeon managing orbital pathology and posttraumatic orbital deformities can benefit immensely from utilizing virtual planning for various types of orbital pathology. PMID:26692714
Nasal reconstruction using porous polyethylene implants.
Romo, T; Sclafani, A P; Jacono, A A
2000-01-01
Nasal reconstruction presents a significant challenge to the facial plastic surgeon. The dual goals of reconstruction are restoration of the desired aesthetic nasal contour and an improved nasal airway. Autologous cartilage and bone are considered optimal grafting material, but their supply is often limited and harvesting entails additional morbidity. Many synthetic materials have been introduced in nasal reconstruction, but high infection and extrusion rates limited their use. Porous high density polyethylene implants present an alternative to autologous material as they allow for fibrovascular ingrowth, leading to stability of the implant and decreased rates of infection. Herein we describe the use of porous high density polyethylene implants for reconstruction of the platyrrhine nose and in revision rhinoplasty. The use of preformed nasal-dorsal tip and alar batten implants are described, as well as the use of columellar strut and premaxillary plumper implants. We believe that porous high density polyethylene implants provide a safe, desirable alternative in functional and aesthetic nasal reconstruction.
Special issues in plastic and reconstructive surgery.
Fulda, Gerard J; Khan, Sami U; Zabel, David D
2003-01-01
Intensivists frequently collaborate with plastic and reconstructive surgeons in treating patients with major wounds, following significant reconstructive procedures, and following free-tissue transfers. Pressure ulcers are a significant source of morbidity and mortality in the intensive care unit; prevention, early recognition, and multidisciplinary treatment are critical components for successful management. Necrotizing fasciitis is an aggressive, soft-tissue infection that requires rapid diagnosis, early surgical intervention frequent operative debridements, and soft-tissue reconstruction Catastrophic abdominal injuries and infections can be treated with an open abdominal approach and require the expertise of a plastic surgeon to reconstruct the abdominal wall. The success of free-tissue transfers and complex reconstructive procedures requires a thorough understanding of the factors that improve flap survival.
Sensation Following Immediate Breast Reconstruction with Implants.
Lagergren, Jakob; Wickman, Marie; Hansson, Per
2010-01-01
Sensation is a neglected aspect of the outcome of breast reconstructions with implants. The aim of this prospective study was to evaluate the cutaneous somatosensory status in breasts following mastectomy and immediate reconstruction with permanent adjustable prostheses and to analyze the patients' subjective experience of the sensation. Twenty-four consecutive patients diagnosed with invasive or in situ breast carcinoma were examined preoperatively and 2 years after mastectomy and reconstruction, for assessment of perception thresholds for touch, cold, warmth, and heat pain above and below the areola. Von Frey filaments and a Peltier element-based thermode were used. The patients completed a questionnaire concerning their experienced sensation in the reconstructed breast. Using quantitative somato-sensory testing, the sensation to all the examined modalities was significantly impaired compared to preoperatively. Most affected was the area above the areola. Patients given postoperative radiotherapy (n = 9) did not differ from those without radiotherapy (n = 15) regarding any of the modalities. All patients reported reduced sensation in the reconstructed breast compared to that preoperatively. Twenty-three patients stated that the reconstructed breast felt different from the other breast; nevertheless 16 reported that the reconstructed breast felt like a real breast. The study revealed sensation impairment following mastectomy and immediate reconstruction with implants. Patients should be informed about this effect preoperatively to allow adequate expectations regarding the sensation outcome. However, two-thirds of the study patients considered that the reconstructed breast felt like a real breast, which must be one of the main purposes of a breast reconstruction.
NASA Astrophysics Data System (ADS)
Zarei Zefreh, Karim; van Aarle, Wim; Batenburg, K. Joost; Sijbers, Jan
2013-10-01
A new superresolution algorithm is proposed to reconstruct a high-resolution license plate image from a set of low-resolution camera images. The reconstruction methodology is based on the discrete algebraic reconstruction technique (DART), a recently developed reconstruction method. While DART has already been successfully applied in tomographic imaging, it has not yet been transferred to the field of camera imaging. DART is introduced for camera imaging through a demonstration of how prior knowledge of the colors of the license plate can be directly exploited during the reconstruction of a high-resolution image from a set of low-resolution images. Simulation experiments show that DART can reconstruct images with superior quality compared to conventional reconstruction methods.
[Subtotal reconstructive laryngectomy: author's experience].
Calearo, C; Bignardi, L
1989-01-01
The authors conclude 18 year's experience with reconstructive laryngectomy by adopting two surgical techniques for intrinsic laryngeal tumors. The first, where one or both of the arytenoids are conserved, can be applied in cases of supraglottic neoplasms extending to the glottis as well as in glottic cancers where a simple cordectomy is not feasible. In both cases this technique is indicated when at least one arytenoid is respected. The second technique involves removal of both arytenoids and is used in cases of intrinsic supraglottic or glottic tumors extended to both arytenoids. The anatomic-pathological criteria supporting these techniques are: 1) the presence of a fibrous ligament anterior to the arytenoid vocal process. This makes possible proper exeresis within healthy tissue (as can be done in supraglottic surgery due to the anatomic characteristics at the anterior commissure level); 2) neoplastic infiltration of the cricoid cartilage takes place exceptionally in supraglottic and glottic neoplasms; in such cases neoplastic manifestation can be radiographically identified. Generally removal of the soft tissues and of the perichondrium within the cricoid area grants conservative surgery the same oncological radicality as that of total laryngectomy. Insights into restoration of laryngeal function when employing the arytenoid-preserving technique are as follows: 1) conservation of the recurrent nerve(s) 2) pulling the base of the tongue back and downward; close to the crico-arytenoid structure can be achieved by crico-hyoid-pexy. In the technique involving removal of the arytenoid: 1) reconstruction of two pseudo-arytenoids 2) the base of the tongue has to be brought close to the edge of the cricoid cartilage possibly by crico-hyoid-pexy. A total of 21 patients have undergone surgery with these techniques since 1984 and to date no neoplastic recurrences have been observed. Those who underwent surgery where the arytenoids were preserved (16 cases) showed
Neelakandan, R S; Bhargava, Darpan
2012-09-01
Reconstruction of the facial skeleton remains a herculean task for a reconstructive surgeon, even with the availability of ample reconstructive options. Transport distraction osteogenesis is a novel reconstructive modality in the armamentarium of a maxillofacial reconstructive surgeon with obvious advantages of osteogenesis and histogenesis from the residual host tissues after tumor ablative surgeries or trauma and also, precludes donor site morbidity. This paper reviews the current concepts, principles involved and applications of transport distraction osteogenesis in maxillomandibular reconstruction.
Microsurgical free flaps: Controversies in maxillofacial reconstruction
George, Rinku K.; Krishnamurthy, Arvind
2013-01-01
Reconstructive microsurgery for oral and maxillofacial (OMF) defects is considered as a niche specialty and is performed regularly only in a handful of centers. Till recently the pectoralis major myocutaneous flap (PMMC) was considered to be the benchmark for OMF reconstruction. This philosophy is changing fast with rapid advancement in reconstructive microsurgery. Due to improvement in instrumentation and the development of finer techniques of flap harvesting we can positively state that microsurgery has come of age. Better techniques, microscopes and micro instruments enable us to do things previously unimaginable. Supramicrosurgery and ultrathin flaps are a testimony to this. Years of innovation in reconstructive microsurgery have given us a reasonably good number of very excellent flaps. Tremendous work has been put into producing some exceptionally brilliant research articles, sometimes contradicting each other. This has led to the need for clarity in some areas in this field. This article will review some controversies in reconstructive microsurgery and analyze some of the most common microvascular free flaps (MFF) used in OMF reconstruction. It aims to buttress the fact that three flaps-the radial forearm free flap (RFFF), anterolateral thigh flap (ALT) and fibula are the ones most expedient in the surgeon's arsenal, since they can cater to almost all sizeable defects we come across after ablative surgery in the OMF region. They can thus aptly be titled as the workhorses of OMF reconstruction with regard to free flaps. PMID:23662264
Live ultrasound volume reconstruction using scout scanning
NASA Astrophysics Data System (ADS)
Meyer, Amelie; Lasso, Andras; Ungi, Tamas; Fichtinger, Gabor
2015-03-01
Ultrasound-guided interventions often necessitate scanning of deep-seated anatomical structures that may be hard to visualize. Visualization can be improved using reconstructed 3D ultrasound volumes. High-resolution 3D reconstruction of a large area during clinical interventions is challenging if the region of interest is unknown. We propose a two-stage scanning method allowing the user to perform quick low-resolution scouting followed by high-resolution live volume reconstruction. Scout scanning is accomplished by stacking 2D tracked ultrasound images into a low-resolution volume. Then, within a region of interest defined in the scout scan, live volume reconstruction can be performed by continuous scanning until sufficient image density is achieved. We implemented the workflow as a module of the open-source 3D Slicer application, within the SlicerIGT extension and building on the PLUS toolkit. Scout scanning is performed in a few seconds using 3 mm spacing to allow region of interest definition. Live reconstruction parameters are set to provide good image quality (0.5 mm spacing, hole filling enabled) and feedback is given during live scanning by regularly updated display of the reconstructed volume. Use of scout scanning may allow the physician to identify anatomical structures. Subsequent live volume reconstruction in a region of interest may assist in procedures such as targeting needle interventions or estimating brain shift during surgery.
Maxillary reconstruction: Current concepts and controversies
Iyer, Subramania; Thankappan, Krishnakumar
2014-01-01
Maxillary reconstruction is still an evolving art when compared to the reconstruction of the mandible. The defects of maxilla apart from affecting the functions of the speech, swallowing and mastication also cause cosmetic disfigurement. Rehabilitation of the form and function in patients with maxillary defects is either by using an obturator prosthesis or by a surgical reconstruction. Literature is abundant with a variety of reconstructive methods. The classification systems are also varied, with no universal acceptance of any one of them. The oncologic safety of these procedures is still debated, and conclusive evidence in this regard has not emerged yet. Management of the orbit is also not yet addressed properly. Tissue engineering, that has been hyped to be one of the possible solutions for this vexing reconstructive problem, has not come out with reliable and reproducible results so far. This review article discusses the rationale and oncological safety of the reconstructing the maxillary defects, critically analyzes the classification systems, offers the different reconstructive methods and touches upon the controversies in this subject. The management of the retained and exenterated orbit associated with maxillectomy is reviewed. The surgical morbidity, complications and the recent advances in this field are also looked into. An algorithm, based on our experience, is presented. PMID:24987199
a Line-Based 3d Roof Model Reconstruction Algorithm: Tin-Merging and Reshaping (tmr)
NASA Astrophysics Data System (ADS)
Rau, J.-Y.
2012-07-01
Three-dimensional building model is one of the major components of a cyber-city and is vital for the realization of 3D GIS applications. In the last decade, the airborne laser scanning (ALS) data is widely used for 3D building model reconstruction and object extraction. Instead, based on 3D roof structural lines, this paper presents a novel algorithm for automatic roof models reconstruction. A line-based roof model reconstruction algorithm, called TIN-Merging and Reshaping (TMR), is proposed. The roof structural line, such as edges, eaves and ridges, can be measured manually from aerial stereo-pair, derived by feature line matching or inferred from ALS data. The originality of the TMR algorithm for 3D roof modelling is to perform geometric analysis and topology reconstruction among those unstructured lines and then reshapes the roof-type using elevation information from the 3D structural lines. For topology reconstruction, a line constrained Delaunay Triangulation algorithm is adopted where the input structural lines act as constraint and their vertex act as input points. Thus, the constructed TINs will not across the structural lines. Later at the stage of Merging, the shared edge between two TINs will be check if the original structural line exists. If not, those two TINs will be merged into a polygon. Iterative checking and merging of any two neighboured TINs/Polygons will result in roof polygons on the horizontal plane. Finally, at the Reshaping stage any two structural lines with fixed height will be used to adjust a planar function for the whole roof polygon. In case ALS data exist, the Reshaping stage can be simplified by adjusting the point cloud within the roof polygon. The proposed scheme reduces the complexity of 3D roof modelling and makes the modelling process easier. Five test datasets provided by ISPRS WG III/4 located at downtown Toronto, Canada and Vaihingen, Germany are used for experiment. The test sites cover high rise buildings and residential
Information reconstruction from speckle interferograms
NASA Astrophysics Data System (ADS)
Mueller, Manfred
The resolving power of the conventional recorded astrophotography is limited to 1 arc second, although the theoretical value is 0.03 arc second. This distorsion is caused by the earth atmosphere. The refractive index oscillations in the terrestrial atmosphere distort incident fronts that interfere in the local plane and produce interferences samples; the speckle interferograms, which are achieved with terrestrial telescopes and in coded shape contain very interesting information about the lifted object and the earth atmosphere. For the space telescope, there are speckles caused by the aberration that will provoke a resolution drop of the telescope in ultraviolet light. The optical parameters of the terrestrial atmosphere and the Hubble Space Telescope (HST) are described. The roll deconvolution method can improve the resolution of the HST from 50 arc ms to 15 arc ms. The reconstruction can be obtained with complex inverse filtering of two HST filmings. An optical digital simulation shows the dependence of the signal to noise ratio on the structure of the point image and the photon noise.
Reconstructing HST Images of Asteroids
NASA Astrophysics Data System (ADS)
Storrs, A. D.; Bank, S.; Gerhardt, H.; Makhoul, K.
2003-12-01
We present reconstructions of images of 22 large main belt asteroids that were observed by Hubble Space Telescope with the Wide-Field/Planetary cameras. All images were restored with the MISTRAL program (Mugnier, Fusco, and Conan 2003) at enhanced spatial resolution. This is possible thanks to the well-studied and stable point spread function (PSF) on HST. We present some modeling of this process and determine that the Strehl ratio for WF/PC (aberrated) images can be improved to 130 ratio of 80 We will report sizes, shapes, and albedos for these objects, as well as any surface features. Images taken with the WFPC-2 instrument were made in a variety of filters so that it should be possible to investigate changes in mineralogy across the surface of the larger asteroids in a manner similar to that done on 4 Vesta by Binzel et al. (1997). Of particular interest are a possible water of hydration feature on 1 Ceres, and the non-observation of a constriction or gap between the components of 216 Kleopatra. Reduction of this data was aided by grant HST-GO-08583.08A from the Space Telescope Science Institute. References: Mugnier, L.M., T. Fusco, and J.-M. Conan, 2003. JOSA A (submitted) Binzel, R.P., Gaffey, M.J., Thomas, P.C., Zellner, B.H., Storrs, A.D., and Wells, E.N. 1997. Icarus 128 pp. 95-103
High-Performance Phylogeny Reconstruction
Tiffani L. Williams
2004-11-10
Under the Alfred P. Sloan Fellowship in Computational Biology, I have been afforded the opportunity to study phylogenetics--one of the most important and exciting disciplines in computational biology. A phylogeny depicts an evolutionary relationship among a set of organisms (or taxa). Typically, a phylogeny is represented by a binary tree, where modern organisms are placed at the leaves and ancestral organisms occupy internal nodes, with the edges of the tree denoting evolutionary relationships. The task of phylogenetics is to infer this tree from observations upon present-day organisms. Reconstructing phylogenies is a major component of modern research programs in many areas of biology and medicine, but it is enormously expensive. The most commonly used techniques attempt to solve NP-hard problems such as maximum likelihood and maximum parsimony, typically by bounded searches through an exponentially-sized tree-space. For example, there are over 13 billion possible trees for 13 organisms. Phylogenetic heuristics that quickly analyze large amounts of data accurately will revolutionize the biological field. This final report highlights my activities in phylogenetics during the two-year postdoctoral period at the University of New Mexico under Prof. Bernard Moret. Specifically, this report reports my scientific, community and professional activities as an Alfred P. Sloan Postdoctoral Fellow in Computational Biology.
Carboniferous paleogeographic and paleoclimatic reconstructions
Scotese, C.R. . Dept. of Geology); Raymond, A. . Dept. Geology)
1992-01-01
The Carboniferous was an important transitional period in earth history. The Paleozoic oceans separating the continents of Gondwana, Laurentia, Baltica, Kazakhstan, and Siberia had closed by the late Carboniferous forming the late Paleozoic supercontinent of Pangea. Plate motions which appear to have been rapid during the Early Carboniferous (6--10 cm/yr), slowed to a temperature gradient increased as the Earth's climate changed from hot-house to ice-house conditions. Sea level, which stood high during the Early Carboniferous, fell as a result of continental collision and mountain-building, and then began to rise and fall rhythmically as the South Polar ice-cap waxed and waned. These environmental changes intersected important evolutionary events, namely, the explosive colonization of the emergent land areas by plants and the rise of terrestrial vertebrates. In this paper the authors present paleogeographic reconstructions for 6 intervals during the Carboniferous. These maps illustrate the latitudinal position of the continents deduced from paleomagnetic data and the distribution of climatically restricted lithofacies (coal, bauxite, evaporite, calcrete, and tillite), the inferred location of active plate boundaries, and the changing configuration of mountains, land, shallow seas, and deep ocean basins. For each of these paleogeographic maps a climatic simulation was run using the Parametric Climate Model. These simulations predict the distribution of high and low pressure cells, prevailing wind directions, pole-to-equator temperature gradient, relative wetness/dryness, as well as zones of coastal upwelling.
Advances in thermographic signal reconstruction
NASA Astrophysics Data System (ADS)
Shepard, Steven M.; Frendberg Beemer, Maria
2015-05-01
Since its introduction in 2001, the Thermographic Signal Reconstruction (TSR) method has emerged as one of the most widely used methods for enhancement and analysis of thermographic sequences, with applications extending beyond industrial NDT into biomedical research, art restoration and botany. The basic TSR process, in which a noise reduced replica of each pixel time history is created, yields improvement over unprocessed image data that is sufficient for many applications. However, examination of the resulting logarithmic time derivatives of each TSR pixel replica provides significant insight into the physical mechanisms underlying the active thermography process. The deterministic and invariant properties of the derivatives have enabled the successful implementation of automated defect recognition and measurement systems. Unlike most approaches to analysis of thermography data, TSR does not depend on flawbackground contrast, so that it can also be applied to characterization and measurement of thermal properties of flaw-free samples. We present a summary of recent advances in TSR, a review of the underlying theory and examples of its implementation.
Surgical Reconstruction of Radiation Injuries
Fujioka, Masaki
2014-01-01
Significance: Patients with cancer receive benefits from radiation therapy; however, it may have adverse effects on normal tissue such as causing radiation-induced ulcer and osteoradionecrosis. The most reliable method to treat a radiation ulcer is wide excision of the affected tissue, followed by coverage with well-vascularized tissue. As usual, radiation-induced skin ulcers are due to therapeutic irradiation for residual cancer or lymph nodes; the locations of radiation ulcers are relatively limited, including the head, neck, chest wall, lumbar, groin, and sacral areas. Thus, suitable reconstructive methods vary according to functional and aesthetic conditions. I reviewed the practices and surgical results for radiation ulcers over the past 30 years, and present the recommended surgical methods for these hard-to-heal ulcers. Recent Advances: At a minimum, flaps are required to treat radiation ulcers. Surgeons can recommend earlier debridement, followed by immediate coverage with axial-pattern musculocutaneous and fasciocutaneous flaps. Free flaps are also a useful soft tissue coverage option. The choice of flap varies with the location and size of the wounds. Critical Issues: The most crucial procedure is the complete resection of the radiation-affected area, followed by coverage with well-vascularized tissue. Future Directions: Recent developments in perforator flap techniques, which are defined as flaps with a blood supply from isolated perforating vessels of a stem artery, have allowed the surgeons to successfully resurface these difficult wounds with reduced morbidity. PMID:24761342
Ligament Injury, Reconstruction and Osteoarthritis
Fleming, Braden C.; Hulstyn, Michael J.; Oksendahl, Heidi L.; Fadale, Paul D.
2007-01-01
Purpose of Review The recent literature on the factors that initiate and accelerate the progression of osteoarthritis following ligament injuries and their treatment is reviewed. Recent Findings The ligament-injured joint is at high risk for osteoarthritis. Current conservative (e.g. rehabilitation) and surgical (e.g. reconstruction) treatment options appear not to reduce osteoarthritis following ligament injury. The extent of osteoarthritis does not appear dependent on which joint is affected, or the presence of damage to other tissues within the joint. Mechanical instability is the likely initiator of osteoarthritis in the ligament-injured patient. Summary The mechanism osteoarthritis begins with the injury rendering the joint unstable. The instability increases the sliding between the joint surfaces and reduces the efficiency of the muscles, factors that alter joint contact mechanics. The load distribution in the cartilage and underlying bone is disrupted, causing wear and increasing shear, which eventually leads to the osteochondral degeneration. The catalyst to the mechanical process is the inflammation response induced by the injury and sustained during healing. In contrast, the inflammation could be responsible for onset, while the mechanical factors accelerate progression. The mechanisms leading to osteoarthritis following ligament injury have not been fully established. A better understanding of these mechanisms should lead to alternative surgical, drug, and tissue-engineering treatment options, which could eliminate osteoarthritis in these patients. Progress is being made on all fronts. Considering that osteoarthritis is likely to occur despite current treatment options, the best solution may be prevention. PMID:17710194
Dubois, Leander; Schreurs, Ruud; Jansen, Jesper; Maal, Thomas J J; Essig, Harald; Gooris, Peter J J; Becking, Alfred G
2015-12-01
Preformed orbital reconstruction plates are useful for treating orbital defects. However, intraoperative errors can lead to misplaced implants and poor outcomes. Navigation-assisted surgery may help optimize orbital reconstruction. We aimed to explore whether navigation-assisted surgery is more predictable than traditional orbital reconstruction for optimal implant placement. Pre-injury computed tomography scans were obtained for 10 cadaver heads (20 orbits). Complex orbital fractures (Class III-IV) were created in all orbits, which were reconstructed using a transconjunctival approach with and without navigation. The best possible fit of the stereolithographic file of a preformed orbital mesh plate was used as the optimal position for reconstruction. The accuracy of the implant positions was evaluated using iPlan software. The consistency of orbital reconstruction was lower in the traditional reconstructions than in the navigation group in the parameters of translation and rotation. Implant position also differed significantly in the parameters of translation (p = 0.002) and rotation (pitch: p = 0.77; yaw: p < 0.001; roll: p = 0.001). Compared with traditional orbital reconstruction, navigation-assisted reconstruction provides more predictable anatomical reconstruction of complex orbital defects and significantly improves orbital implant position.
Asymmetry in the reconstructed deceleration parameter
NASA Astrophysics Data System (ADS)
Bernal, Carla; Cárdenas, Víctor H.; Motta, Veronica
2017-02-01
We study the orientation dependence of the reconstructed deceleration parameter as a function of redshift. We use the Union 2 and Loss datasets, and the well known preferred axis discussed in the literature, and find the best fit reconstructed deceleration parameter. Our results show that a low redshift transition of the reconstructed q (z) is clearly absent in one direction and amazingly sharp in the opposite one. We discuss the possibility that such behavior can be associated to large scale structures affecting the data.
Material Interface Reconstruction in VisIt
Meredith, J S
2005-01-27
In this paper, we first survey a variety of approaches to material interface reconstruction and their applicability to visualization, and we investigate the details of the current reconstruction algorithm in the VisIt scientific analysis and visualization tool. We then provide a novel implementation of the original VisIt algorithm that makes use of a wide range of the finite element zoo during reconstruction. This approach results in dramatic improvements in quality and performance without sacrificing the strengths of the VisIt algorithm as it relates to visualization.
Developing population estimates for dose reconstruction projects
Beck, D.M. )
1991-01-01
The Hanford Environmental Dose Reconstruction (HEDR) Project was established in 1987 to estimate radiation doses that people received from nuclear operations at the Hanford site since 1944. To achieve this objective, demographic information was developed that describes the study population in enough detail to allow researchers to identify potentially exposed groups and the number of people in each of those groups. This type of information is central to most dose reconstruction projects. The purpose of this paper is to detail how historical population estimates can be reconstructed in a reliable manner by comparing results using three different estimation methods.
Maximizing results in reconstruction of cheek defects.
Mureau, Marc A M; Hofer, Stefan O P
2009-07-01
The face is exceedingly important, as it is the medium through which individuals interact with the rest of society. Reconstruction of cheek defects after trauma or surgery is a continuing challenge for surgeons who wish to reliably restore facial function and appearance. Important in aesthetic facial reconstruction are the aesthetic unit principles, by which the face can be divided in central facial units (nose, lips, eyelids) and peripheral facial units (cheeks, forehead, chin). This article summarizes established options for reconstruction of cheek defects and provides an overview of several modifications as well as tips and tricks to avoid complications and maximize aesthetic results.
Acoustic imaging for temperature distribution reconstruction
NASA Astrophysics Data System (ADS)
Jia, Ruixi; Xiong, Qingyu; Liang, Shan
2016-12-01
For several industrial processes, such as burning and drying, temperature distribution is important because it can reflect the internal running state of industrial equipment and assist to develop control strategy and ensure safety in operation of industrial equipment. The principle of this technique is mainly based on the relationship between acoustic velocity and temperature. In this paper, an algorithm for temperature distribution reconstruction is considered. Compared with reconstruction results of simulation experiments with the least square algorithm and the proposed one, the latter indicates a better information reflection of temperature distribution and relatively higher reconstruction accuracy.
NASA Astrophysics Data System (ADS)
Hung, Linda; da Jornada, Felipe H.; Souto-Casares, Jaime; Chelikowsky, James R.; Louie, Steven G.; Ã-ǧüt, Serdar
2016-08-01
We present first-principles calculations on the vertical ionization potentials (IPs), electron affinities (EAs), and singlet excitation energies on an aromatic-molecule test set (benzene, thiophene, 1,2,5-thiadiazole, naphthalene, benzothiazole, and tetrathiafulvalene) within the G W and Bethe-Salpeter equation (BSE) formalisms. Our computational framework, which employs a real-space basis for ground-state and a transition-space basis for excited-state calculations, is well suited for high-accuracy calculations on molecules, as we show by comparing against G0W0 calculations within a plane-wave-basis formalism. We then generalize our framework to test variants of the G W approximation that include a local density approximation (LDA)-derived vertex function (ΓLDA) and quasiparticle-self-consistent (QS) iterations. We find that ΓLDA and quasiparticle self-consistency shift IPs and EAs by roughly the same magnitude, but with opposite sign for IPs and the same sign for EAs. G0W0 and QS G W ΓLDA are more accurate for IPs, while G0W0ΓLDA and QS G W are best for EAs. For optical excitations, we find that perturbative G W -BSE underestimates the singlet excitation energy, while self-consistent G W -BSE results in good agreement with previous best-estimate values for both valence and Rydberg excitations. Finally, our work suggests that a hybrid approach, in which G0W0 energies are used for occupied orbitals and G0W0ΓLDA for unoccupied orbitals, also yields optical excitation energies in good agreement with experiment but at a smaller computational cost.
Salvatore, B.; Caprio, M.G.; Fonti, R.; D’Amico, D.; Fraioli, F.; Salvatore, M.; Pace, L.
2015-01-01
Aim To assess whether performing routinely 2-deoxy-2-[18F]fluoro-D-glucose PET/CT (18FDG PET/CT) scan from the upper thigh to the vertex of skull is clinically relevant. Materials and Methods: 3502 (1634 female; mean-age 60+16) consecutive patients undergoing 18FDG PET/CT were retrospectively analyzed. Patients were divided in 10 groups according to primary malignancy. Chi-square analysis was used to assess differences among proportions. A p value < 0.05 was considered significant. Results: 18FDG PET/CT was positive in head district in 130/3502 (3,7%) patients. In all patients lesions were unknown before PET/CT examination. PET/CT showed 158 positive brain/head uptake in the 130 patients. The 158 lesions were localized in: brain (43/158; 27%), bone (52/158; 33%), lymph node (1/158; 0,6%), soft tissue (55/158; 35%) and other sites (7/158; 4,4%). According to each group, patients were positive in the head district in 1.0% for Gastrointestinal Cancer (7/690), 3.0 % for Genitourinary Cancer (3/101), 3.7 % for Haemathologic Cancer (59/1590), 2.7 % for Gynaecologic Cancer (3/112), 7.8% for Head-Neck-Thyroid and Parathyroid Cancer (26/331), 3.5% for Breast Cancer (7/200), 2.6% for Lung Cancer (7/271), 3.4% for Melanoma (2/59), 7.4% for Sarcoma (2/27), 11.6% for Unknown Primary Tumour (14/121). Conclusion: Our data show a relatively high incidence of brain/head lesion in patients with Unknown Primary Tumour. PMID:25674547
Iterative reconstruction of a region of interest for transmission tomography.
Ziegler, Andy; Nielsen, Tim; Grass, Michael
2008-04-01
It was shown that images reconstructed for transmission tomography with iterative maximum likelihood (ML) algorithms exhibit a higher signal-to-noise ratio than images reconstructed with filtered back-projection type algorithms. However, a drawback of ML reconstruction in particular and iterative reconstruction in general is the requirement that the reconstructed field of view (FOV) has to cover the whole volume that contributes to the absorption. In the case of a high resolution reconstruction, this demands a huge number of voxels. This article shows how an iterative ML reconstruction can be limited to a region of interest (ROI) without losing the advantages of a ML reconstruction. Compared with a full FOV ML reconstruction, the reconstruction speed is mainly increased by reducing the number of voxels which are necessary for a ROI reconstruction. In addition, the speed of convergence is increased.
Diffraction Correlation to Reconstruct Highly Strained Particles
NASA Astrophysics Data System (ADS)
Brown, Douglas; Harder, Ross; Clark, Jesse; Kim, J. W.; Kiefer, Boris; Fullerton, Eric; Shpyrko, Oleg; Fohtung, Edwin
2015-03-01
Through the use of coherent x-ray diffraction a three-dimensional diffraction pattern of a highly strained nano-crystal can be recorded in reciprocal space by a detector. Only the intensities are recorded, resulting in a loss of the complex phase. The recorded diffraction pattern therefore requires computational processing to reconstruct the density and complex distribution of the diffracted nano-crystal. For highly strained crystals, standard methods using HIO and ER algorithms are no longer sufficient to reconstruct the diffraction pattern. Our solution is to correlate the symmetry in reciprocal space to generate an a priori shape constraint to guide the computational reconstruction of the diffraction pattern. This approach has improved the ability to accurately reconstruct highly strained nano-crystals.
Breast Reconstruction - Multiple Languages: MedlinePlus
... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Breast Reconstruction URL of this page: https://medlineplus.gov/languages/breastreconstruction.html Other topics A-Z A B ...
Chest wall reconstruction after extended resection
Seder, Christopher W.
2016-01-01
Extensive chest wall resection and reconstruction is a challenging procedure that requires a multidisciplinary approach, including input from thoracic surgeons, plastic surgeons, neurosurgeons, and radiation oncologists. The primary goals of any chest wall reconstruction is to obliterate dead space, restore chest wall rigidity, preserve pulmonary mechanics, protect intrathoracic organs, provide soft tissue coverage, minimize deformity, and allow patients to receive adjuvant radiotherapy. Successful chest wall reconstruction requires the re-establishment of skeletal stability to prevent chest wall hernias, avoids thoracoplasty-like contraction of the operated side, protects underlying viscera, and maintain a cosmetically-acceptable appearance. After skeletal stability is established, full tissue coverage can be achieved using direct closure, skin grafts, local advancement flaps, pedicled myocutaneous flaps, or free flaps. This review examines the indications for chest wall reconstruction and describes techniques for establishment of chest wall rigidity and soft tissue coverage. PMID:27942408
Towards an optimal reconstruction of baryon oscillations
Tassev, Svetlin; Zaldarriaga, Matias E-mail: matiasz@ias.edu
2012-10-01
The Baryon Acoustic Oscillations (BAO) in the large-scale structure of the universe leave a distinct peak in the two-point correlation function of the matter distribution. That acoustic peak is smeared and shifted by bulk flows and non-linear evolution. However, it has been shown that it is still possible to sharpen the peak and remove its shift by undoing the effects of the bulk flows. We propose an improvement to the standard acoustic peak reconstruction. Contrary to the standard approach, the new scheme has no free parameters, treats the large-scale modes consistently, and uses optimal filters to extract the BAO information. At redshift of zero, the reconstructed linear matter power spectrum leads to a markedly improved sharpening of the reconstructed acoustic peak compared to standard reconstruction.
Lateral ligament reconstruction procedures for the ankle.
Tourné, Y; Mabit, C
2017-02-01
Capsule/ligament lesions of the lateral compartment of the ankle lead to lateral laxity, which is a prime contributor to chronic ankle instability. Lateral ligament reconstruction stabilizes the joint. Exhaustive preoperative clinical and paraclinical work-up is essential. The present article classifies, presents and criticizes the main techniques in terms of long-term stabilization and reduction of osteoarthritis risk. Anatomic ligament repair with reinforcement (mainly extensor retinaculum) or anatomic ligament reconstruction are the two recommended options. Non-anatomic reconstructions using the peroneus brevis should be abandoned. Arthroscopy is increasingly being developed, but results need assessment on longer follow-up than presently available. Postoperative neuromuscular reprogramming is fundamental to optimal recovery. Finally, the concept of complex ankle instability is discussed from the diagnostic and therapeutic points of view. The various forms of ligament reconstruction failure and corresponding treatments are reported.
Image reconstruction for robot assisted ultrasound tomography
NASA Astrophysics Data System (ADS)
Aalamifar, Fereshteh; Zhang, Haichong K.; Rahmim, Arman; Boctor, Emad M.
2016-04-01
An investigation of several image reconstruction methods for robot-assisted ultrasound (US) tomography setup is presented. In the robot-assisted setup, an expert moves the US probe to the location of interest, and a robotic arm automatically aligns another US probe with it. The two aligned probes can then transmit and receive US signals which are subsequently used for tomographic reconstruction. This study focuses on reconstruction of the speed of sound. In various simulation evaluations as well as in an experiment with a millimeter-range inaccuracy, we demonstrate that the limited data provided by two probes can be used to reconstruct pixel-wise images differentiating between media with different speeds of sound. Combining the results of this investigation with the developed robot-assisted US tomography setup, we envision feasibility of this setup for tomographic imaging in applications beyond breast imaging, with potentially significant efficacy in cancer diagnosis.
Image Reconstruction Using Analysis Model Prior
Han, Yu; Du, Huiqian; Lam, Fan; Mei, Wenbo; Fang, Liping
2016-01-01
The analysis model has been previously exploited as an alternative to the classical sparse synthesis model for designing image reconstruction methods. Applying a suitable analysis operator on the image of interest yields a cosparse outcome which enables us to reconstruct the image from undersampled data. In this work, we introduce additional prior in the analysis context and theoretically study the uniqueness issues in terms of analysis operators in general position and the specific 2D finite difference operator. We establish bounds on the minimum measurement numbers which are lower than those in cases without using analysis model prior. Based on the idea of iterative cosupport detection (ICD), we develop a novel image reconstruction model and an effective algorithm, achieving significantly better reconstruction performance. Simulation results on synthetic and practical magnetic resonance (MR) images are also shown to illustrate our theoretical claims. PMID:27379171
Maximum Likelihood Reconstruction for Magnetic Resonance Fingerprinting
Zhao, Bo; Setsompop, Kawin; Ye, Huihui; Cauley, Stephen; Wald, Lawrence L.
2017-01-01
This paper introduces a statistical estimation framework for magnetic resonance (MR) fingerprinting, a recently proposed quantitative imaging paradigm. Within this framework, we present a maximum likelihood (ML) formalism to estimate multiple parameter maps directly from highly undersampled, noisy k-space data. A novel algorithm, based on variable splitting, the alternating direction method of multipliers, and the variable projection method, is developed to solve the resulting optimization problem. Representative results from both simulations and in vivo experiments demonstrate that the proposed approach yields significantly improved accuracy in parameter estimation, compared to the conventional MR fingerprinting reconstruction. Moreover, the proposed framework provides new theoretical insights into the conventional approach. We show analytically that the conventional approach is an approximation to the ML reconstruction; more precisely, it is exactly equivalent to the first iteration of the proposed algorithm for the ML reconstruction, provided that a gridding reconstruction is used as an initialization. PMID:26915119
Tilted cone beam VCT reconstruction algorithm
NASA Astrophysics Data System (ADS)
Hsieh, Jiang; Tang, Xiangyang
2005-04-01
Reconstruction algorithms for volumetric CT have been the focus of many studies. Several exact and approximate reconstruction algorithms have been proposed for step-and-shoot and helical scanning trajectories to combat cone beam related artifacts. In this paper, we present a closed form cone beam reconstruction formula for tilted gantry data acquisition. Although several algorithms were proposed to compensate for errors induced by the gantry tilt, none of the algorithms addresses the case in which the cone beam geometry is first rebinned to a set of parallel beams prior to the filtered backprojection. Because of the rebinning process, the amount of iso-center adjustment depends not only on the projection angle and tilt angle, but also on the reconstructed pixel location. The proposed algorithm has been tested extensively on both 16 and 64 slice VCT with phantoms and clinical data. The efficacy of the algorithm is clearly demonstrated by the experiments.
Traumatic Forefoot Reconstructions With Free Perforator Flaps.
Zhu, Yue-Liang; He, Xiao-Qing; Wang, Yi; Lv, Qian; Fan, Xin-Yv; Xu, Yong-Qing
2015-01-01
The forefoot is critical to normal walking; thus, any reconstruction of forefoot defects, including the soft tissues, must be carefully done. The free perforator flap, with its physiologic circulation, lower donor site morbidity, and minimal thickness is the most popular technique in plastic and microsurgery, and is theoretically the most suitable for such forefoot reconstruction. However, these flaps are generally recognized as more difficult and time-consuming to create than other flaps. In 41 patients with traumatic forefoot defects, we reconstructed the forefoot integument using 5 types of free perforator flaps. The overall functional and cosmetic outcomes were excellent. Three flaps required repeat exploration; one survived. The most common complications were insufficient perfusion and the need for second debulking. The key to our success was thoroughly debriding devitalized bone and soft tissue before attaching the flap. Forefoot reconstruction with a free perforator flap provides better function, better cosmesis, better weightbearing, and better gait than the other flaps we have used.
Point estimates in phylogenetic reconstructions
Benner, Philipp; Bačák, Miroslav; Bourguignon, Pierre-Yves
2014-01-01
Motivation: The construction of statistics for summarizing posterior samples returned by a Bayesian phylogenetic study has so far been hindered by the poor geometric insights available into the space of phylogenetic trees, and ad hoc methods such as the derivation of a consensus tree makeup for the ill-definition of the usual concepts of posterior mean, while bootstrap methods mitigate the absence of a sound concept of variance. Yielding satisfactory results with sufficiently concentrated posterior distributions, such methods fall short of providing a faithful summary of posterior distributions if the data do not offer compelling evidence for a single topology. Results: Building upon previous work of Billera et al., summary statistics such as sample mean, median and variance are defined as the geometric median, Fréchet mean and variance, respectively. Their computation is enabled by recently published works, and embeds an algorithm for computing shortest paths in the space of trees. Studying the phylogeny of a set of plants, where several tree topologies occur in the posterior sample, the posterior mean balances correctly the contributions from the different topologies, where a consensus tree would be biased. Comparisons of the posterior mean, median and consensus trees with the ground truth using simulated data also reveals the benefits of a sound averaging method when reconstructing phylogenetic trees. Availability and implementation: We provide two independent implementations of the algorithm for computing Fréchet means, geometric medians and variances in the space of phylogenetic trees. TFBayes: https://github.com/pbenner/tfbayes, TrAP: https://github.com/bacak/TrAP. Contact: philipp.benner@mis.mpg.de PMID:25161244
Language distance and tree reconstruction
NASA Astrophysics Data System (ADS)
Petroni, Filippo; Serva, Maurizio
2008-08-01
Languages evolve over time according to a process in which reproduction, mutation and extinction are all possible. This is very similar to haploid evolution for asexual organisms and for the mitochondrial DNA of complex ones. Exploiting this similarity, it is possible, in principle, to verify hypotheses concerning the relationship among languages and to reconstruct their family tree. The key point is the definition of the distances among pairs of languages in analogy with the genetic distances among pairs of organisms. Distances can be evaluated by comparing grammar and/or vocabulary, but while it is difficult, if not impossible, to quantify grammar distance, it is possible to measure a distance from vocabulary differences. The method used by glottochronology computes distances from the percentage of shared 'cognates', which are words with a common historical origin. The weak point of this method is that subjective judgment plays a significant role. Here we define the distance of two languages by considering a renormalized edit distance among words with the same meaning and averaging over the two hundred words contained in a Swadesh list. In our approach the vocabulary of a language is the analogue of DNA for organisms. The advantage is that we avoid subjectivity and, furthermore, reproducibility of results is guaranteed. We apply our method to the Indo-European and the Austronesian groups, considering, in both cases, fifty different languages. The two trees obtained are, in many respects, similar to those found by glottochronologists, with some important differences as regards the positions of a few languages. In order to support these different results we separately analyze the structure of the distances of these languages with respect to all the others.
Viel, Guido; Cecchetto, Giovanni; Manara, Renzo; Cecchetto, Attilio; Montisci, Massimo
2011-06-01
Patients affected by cranial trauma with depressed skull fractures and increased intracranial pressure generally undergo neurosurgical intervention. Because craniotomy and craniectomy remove skull fragments and generate new fracture lines, they complicate forensic examination and sometimes prevent a clear identification of skull fracture etiology. A 3-dimensional reconstruction based on preoperative computed tomography (CT) scans, giving a picture of the injuries before surgical intervention, can help the forensic examiner in identifying skull fracture origin and the means of production.We report the case of a 41-year-old-man presenting at the emergency department with a depressed skull fracture at the vertex and bilateral subdural hemorrhage. The patient underwent 2 neurosurgical interventions (craniotomy and craniectomy) but died after 40 days of hospitalization in an intensive care unit. At autopsy, the absence of various bone fragments did not allow us to establish if the skull had been stricken by a blunt object or had hit the ground with high kinetic energy. To analyze bone injuries before craniectomy, a 3-dimensional CT reconstruction based on preoperative scans was performed. A comparative analysis between autoptic and radiological data allowed us to differentiate surgical from traumatic injuries. Moreover, based on the shape and size of the depressed skull fracture (measured from the CT reformations), we inferred that the man had been stricken by a cylindric blunt object with a diameter of about 3 cm.
Kühnel, T V; Vairaktaris, E; Alexiou, C; Schlegel, K A; Neukam, F W; Nkenke, E
2008-11-01
Pronounced enophthalmos can restrict patients both functionally and aesthetically. Typical symptoms are double vision on both eyes and obvious asymmetry, both of which were present in the 67-year-old male patient presented in this paper. The resulting data of computed tomography was used to fabricate a patient specific ceramic implant for reconstruction of the left orbital floor with an enophthalmos of 4mm. During the surgery the implant fitted anatomically correct, but exophthalmos occurred. The implant needed to be regraded and recontoured in the dorsal fraction, so that overcorrection could be reduced. With the assistance of optical 3D en- and exophthalmometry during surgery, the position of the cornea vertex was reproducible measured. At the end of surgery, exophthalmos was 1.5 mm. After 12 months, enophthalmos of only 1mm exists. This case displays the combination of a patient specific fabricated implant for reconstruction of the orbital floor with optical 3D-en-and exophthalmometry to correct enophthalmos with a high degree of accuracy. Therefore these two techniques in combination should be used when complex corrections of enophthalmos are needed.
NASA Astrophysics Data System (ADS)
Wahl, E. R.; Cook, E.; Diaz, H. F.; Meko, D. M.
2012-12-01
Well-verified tree ring-based reconstructions of the surface temperature field over the past 500 years in western North America have recently been completed using the principal component spatial regression (PCSR) method. In conjunction with the North American Drought Atlas (NADA) reconstructions of drought index values, constructed using the point-by-point regression (PPR) method, the new spatial temperature reconstructions make it possible to estimate direct moisture fields over western North America for a significant portion of the past millennium. To achieve this goal, experiments will be conducted in which reconstructed temperature, or its equivalent in the form of potential evapotranspiration, will be regressed out of the NADA reconstructions to 'back out' in residual form the contribution of precipitation in the NADA with its regional seasonalities intact. To ensure non-overlap of the temperature and PDSI tree chronology data used, an implementation of the NADA will be done that excludes the proxy data used in the temperature reconstructions. To facilitate examination of maximum comparability of the drought and temperature data, the annual temperature reconstructions also will be calibrated to summer (JJA) temperatures, the NADA seasonality. Bootstrapping methods recently implemented for paleoclimate field reconstruction, the maximum entropy bootstrap for PPR and a modification of bootstrapping from residuals for PCSR, will be evaluated for generation of uncertainty ensemble distributions associated with the derived precipitation reconstructions. Generation of a reconstruction ensemble allows, for example, estimation of the distribution of extreme values or the uncertainty in a temporally smoothed time series, results that cannot readily be obtained from traditional confidence intervals associated with expected value estimates. More generally, the ensemble distribution will allow these regression-based reconstructions to be more meaningfully compared with
Iraq Reconstruction: Lessons from Auditing U.S.-funded Stabilization and Reconstruction Activities
2012-10-01
Activities October 2012 Audit Lessons Learned_v10.indd 1 10/17/2012 6:27:00 PM Report Documentation Page Form ApprovedOMB No. 0704-0188 Public...4. TITLE AND SUBTITLE Iraq Reconstruction: Lessons from Auditing U.S.-funded Stabilization and Reconstruction Activities 5a. CONTRACT NUMBER 5b...Lessons Learned from Auditing Stabilization and Reconstruction Activities in an SRO .................................................. 3 Part III
Prosthodontic Considerations in Post-cancer Reconstructions.
Boonsiriphant, Piriya; Hirsch, Joel A; Greenberg, Alex M; Genden, Eric M
2015-05-01
The restoration of function after oncologic surgery of the oral cavity constitutes one of the major challenges facing head and neck oncology. Within the general objective of securing esthetic as well as functional reconstructions, dental rehabilitation is crucial for achieving a good outcome. Adequate dental rehabilitation allows the patient to chew food and considerably improves speech and swallowing. These reconstructions will be driven biologically or prosthetically following surgical design and outcome.
Iterative wavelet thresholding for rapid MRI reconstruction
NASA Astrophysics Data System (ADS)
Kayvanrad, Mohammad H.; McKenzie, Charles A.; Peters, Terry M.
2011-03-01
According to the developments in the field of compressed sampling and and sparse recovery, one might take advantage of the sparsity of an object, as an additional a priori knowledge about the object, to reconstruct it from fewer samples than that needed by the traditional sampling strategies. Since most magnetic resonance (MR) images are sparse in some domain, in this work we consider the problem of MR reconstruction and how one could apply this idea to accelerate the process of MR image/map acquisition. In particular, based on the Paupolis-Gerchgerg algorithm, an iterative thresholding algorithm for reconstruction of MR images from limited k-space observations is proposed. The proposed method takes advantage of the sparsity of most MR images in the wavelet domain. Initializing with a minimum-energy reconstruction, the object of interest is reconstructed by going through a sequence of thresholding and recovery iterations. Furthermore, MR studies often involve acquisition of multiple images in time that are highly correlated. This correlation can be used as additional knowledge on the object beside the sparsity to further reduce the reconstruction time. The performance of the proposed algorithms is experimentally evaluated and compared to other state-of-the-art methods. In particular, we show that the quality of reconstruction is increased compared to total variation (TV) regularization, and the conventional Papoulis-Gerchberg algorithm both in the absence and in the presence of noise. Also, phantom experiments show good accuracy in the reconstruction of relaxation maps from a set of highly undersampled k-space observations.
Reconstruction for breast cancer in a nutshell.
Harmer, Victoria
Breast cancer is a disease many will experience. Depending on the size of the cancer, the size of the host breast, and whether it is multi-focal, a mastectomy may be recommended as part of the treatment. If this is the case, an immediate breast reconstruction may be offered. This article will describe the three main types of breast reconstruction and discuss pertinent issues regarding this, including complications, surgery to the other (contraleteral) breast and potential psychological implications of this surgery.
Researches on Track Reconstruction for DAMPE
NASA Astrophysics Data System (ADS)
Lu, T. S.; Lei, S. J.; Zang, J. J.; Chang, J.; Wu, J.
2016-05-01
The Dark Matter Particle Explorer (DAMPE) is aimed to study the existence and distribution of dark matter via observation of high energy particles in space with unprecedented large energy bandwidth, high energy resolution, and high space resolution. The track reconstruction is to restore the positions and angles of the incident particles using the multiple observations of different channels at different positions, and its accuracy determines the angular resolution of the detector. The track reconstruction is mainly based on the observations of two sub-detectors, namely, the Silicon Tracker (STK) detector and the BGO (Bi_4Ge_3O12) calorimeter. In accordance with the design and structure of the two sub-detectors and using the data collected during the beam tests and ground tests, we provide a detailed introduction of the track reconstruction of DAMPE data, including three basic steps, the selection of track hits, the fitting of track hits, and the judgement of the best track among (most probably) many of them. Since a high energy particle most probably leaves more than one hit in each level of the STK and BGO, we first provide a method to constrain the STK clusters for the track reconstruction using the rough result of the BGO reconstruction. We apply two different algorithms, the Kalman filter and the least square linear fitting, to fit the track hits. The consistency of the results obtained independently via the two algorithms confirms the validity of our track reconstruction results, and we discuss the advantages/disadvantages of each method. Several criteria combining the BGO and STK detection are discussed for picking out the most possible track among all the tracks found in the track reconstruction. Using the track reconstruction methods mentioned in this article and the beam test data, we confirm that the angular resolution of DAMPE satisfies the requirement in design.
Special Inspector General for Afghanistan Reconstruction (SIGAR)
2013-01-30
through positive interactions with local people. (U.S. Air Force photo) REPORT TO THE UNITED STATES CONGRESS I JANUARY 30, 2013 147 ECONOMIC AND SOCIAL ...Staff SECTION 3 49 RECONSTRUCTION UPDATE 51 Overview 55 Status of Funds 69 Security 95 Governance 123 Economic and Social Development TABLE OF...Governance 95 Economic and Social Development 123 51 51 REPORT TO THE UNITED STATES CONGRESS I JANUARY 30, 2013 RECONSTRUCTION UPDATE OVERVIEW Section 3
Anatomic Variations in Head and Neck Reconstruction
Tan, Bien-Keem; Wong, Chin-Ho; Chen, Hung-Chi
2010-01-01
Head and neck reconstruction is a technically challenging procedure. Variations encountered in the recipient vessels and commonly used flaps add to the complexity of surgery. This article reviews the commonly encountered variations in the recipient vessels in the neck with emphasis on alternatives and techniques to circumvent these variations. Flaps commonly used in head and neck reconstruction are also reviewed in detail. Furthermore, safety, potential pitfalls, and technical pearls are highlighted. PMID:22550436
Bone allografts in reconstructive middle ear surgery.
Gersdorff, M; Vilain, J; Maisin, J P; Munting, E; Delloye, C
1989-01-01
The authors present their current experience with stored bone grafts, using allografts shaped from the cortices of long bones for reconstructing the tympano-ossicular chain. The materials and the methods are described. The anatomical results have been good in 97% of the cases, while the functional results are as satisfactory as those obtained with bioceramics. In addition to ossiculoplasty, the bone allografts can also be used in otology for reconstructing large bony defects of the temporal bone.
RADON reconstruction in longitudinal phase space
Mane, V.; Peggs, S.; Wei, J.
1997-07-01
Longitudinal particle motion in circular accelerators is typically monitoring by one dimensional (1-D) profiles. Adiabatic particle motion in two dimensional (2-D) phase space can be reconstructed with tomographic techniques, using 1-D profiles. A computer program RADON has been developed in C++ to process digitized mountain range data and perform the phase space reconstruction for the AGS, and later for Relativistic Heavy Ion Collider (RHIC).
Post Conflict Reconstruction: A Selected Bibliography
2007-01-01
2005) http:// www.csis.org/isp/ pcr /voa%5Freport.pdf Marshall, A. Phased Withdrawal, Conflict Resolution and State Reconstruction. Camberley, Surrey...115-215. Wilson OmniFile Wardak, Ali. “Building a Post-War Justice System in Afghanistan.” Crime , Law and Social Change 41 (May 2004): 319-341...240. Cambridge: Belknap Press of Harvard University Press, 2004. (CB251 .K26 2004) 17 Labs , Eric J. Paying for Iraq’s Reconstruction
Huang, Austin; Kantor, Rami; DeLong, Allison; Schreier, Leeann; Istrail, Sorin
Next generation sequencing technologies have recently been applied to characterize mutational spectra of the heterogeneous population of viral genotypes (known as a quasispecies) within HIV-infected patients. Such information is clinically relevant because minority genetic subpopulations of HIV within patients enable viral escape from selection pressures such as the immune response and antiretroviral therapy. However, methods for quasispecies sequence reconstruction from next generation sequencing reads are not yet widely used and remains an emerging area of research. Furthermore, the majority of research methodology in HIV has focused on 454 sequencing, while many next-generation sequencing platforms used in practice are limited to shorter read lengths relative to 454 sequencing. Little work has been done in determining how best to address the read length limitations of other platforms. The approach described here incorporates graph representations of both read differences and read overlap to conservatively determine the regions of the sequence with sufficient variability to separate quasispecies sequences. Within these tractable regions of quasispecies inference, we use constraint programming to solve for an optimal quasispecies subsequence determination via vertex coloring of the conflict graph, a representation which also lends itself to data with non-contiguous reads such as paired-end sequencing. We demonstrate the utility of the method by applying it to simulations based on actual intra-patient clonal HIV-1 sequencing data.
Modern concepts in facial nerve reconstruction
2010-01-01
Background Reconstructive surgery of the facial nerve is not daily routine for most head and neck surgeons. The published experience on strategies to ensure optimal functional results for the patients are based on small case series with a large variety of surgical techniques. On this background it is worthwhile to develop a standardized approach for diagnosis and treatment of patients asking for facial rehabilitation. Conclusion A standardized approach is feasible: Patients with chronic facial palsy first need an exact classification of the palsy's aetiology. A step-by-step clinical examination, if necessary MRI imaging and electromyographic examination allow a classification of the palsy's aetiology as well as the determination of the severity of the palsy and the functional deficits. Considering the patient's desire, age and life expectancy, an individual surgical concept is applicable using three main approaches: a) early extratemporal reconstruction, b) early reconstruction of proximal lesions if extratemporal reconstruction is not possible, c) late reconstruction or in cases of congenital palsy. Twelve to 24 months after the last step of surgical reconstruction a standardized evaluation of the therapeutic results is recommended to evaluate the necessity for adjuvant surgical procedures or other adjuvant procedures, e.g. botulinum toxin application. Up to now controlled trials on the value of physiotherapy and other adjuvant measures are missing to give recommendation for optimal application of adjuvant therapies. PMID:21040532
Image reconstruction: an overview for clinicians.
Hansen, Michael S; Kellman, Peter
2015-03-01
Image reconstruction plays a critical role in the clinical use of magnetic resonance imaging (MRI). The MRI raw data is not acquired in image space and the role of the image reconstruction process is to transform the acquired raw data into images that can be interpreted clinically. This process involves multiple signal processing steps that each have an impact on the image quality. This review explains the basic terminology used for describing and quantifying image quality in terms of signal-to-noise ratio and point spread function. In this context, several commonly used image reconstruction components are discussed. The image reconstruction components covered include noise prewhitening for phased array data acquisition, interpolation needed to reconstruct square pixels, raw data filtering for reducing Gibbs ringing artifacts, Fourier transforms connecting the raw data with image space, and phased array coil combination. The treatment of phased array coils includes a general explanation of parallel imaging as a coil combination technique. The review is aimed at readers with no signal processing experience and should enable them to understand what role basic image reconstruction steps play in the formation of clinical images and how the resulting image quality is described.
Nonholonomic catheter path reconstruction using electromagnetic tracking
NASA Astrophysics Data System (ADS)
Lugez, Elodie; Sadjadi, Hossein; Akl, Selim G.; Fichtinger, Gabor
2015-03-01
Catheter path reconstruction is a necessary step in many clinical procedures, such as cardiovascular interventions and high-dose-rate brachytherapy. To overcome limitations of standard imaging modalities, electromagnetic tracking has been employed to reconstruct catheter paths. However, tracking errors pose a challenge in accurate path reconstructions. We address this challenge by means of a filtering technique incorporating the electromagnetic measurements with the nonholonomic motion constraints of the sensor inside a catheter. The nonholonomic motion model of the sensor within the catheter and the electromagnetic measurement data were integrated using an extended Kalman filter. The performance of our proposed approach was experimentally evaluated using the Ascension's 3D Guidance trakStar electromagnetic tracker. Sensor measurements were recorded during insertions of an electromagnetic sensor (model 55) along ten predefined ground truth paths. Our method was implemented in MATLAB and applied to the measurement data. Our reconstruction results were compared to raw measurements as well as filtered measurements provided by the manufacturer. The mean of the root-mean-square (RMS) errors along the ten paths was 3.7 mm for the raw measurements, and 3.3 mm with manufacturer's filters. Our approach effectively reduced the mean RMS error to 2.7 mm. Compared to other filtering methods, our approach successfully improved the path reconstruction accuracy by exploiting the sensor's nonholonomic motion constraints in its formulation. Our approach seems promising for a variety of clinical procedures involving reconstruction of a catheter path.
Hash functions and triangular mesh reconstruction*1
NASA Astrophysics Data System (ADS)
Hrádek, Jan; Kuchař, Martin; Skala, Václav
2003-07-01
Some applications use data formats (e.g. STL file format), where a set of triangles is used to represent the surface of a 3D object and it is necessary to reconstruct the triangular mesh with adjacency information. It is a lengthy process for large data sets as the time complexity of this process is O( N log N), where N is number of triangles. Triangular mesh reconstruction is a general problem and relevant algorithms can be used in GIS and DTM systems as well as in CAD/CAM systems. Many algorithms rely on space subdivision techniques while hash functions offer a more effective solution to the reconstruction problem. Hash data structures are widely used throughout the field of computer science. The hash table can be used to speed up the process of triangular mesh reconstruction but the speed strongly depends on hash function properties. Nevertheless the design or selection of the hash function for data sets with unknown properties is a serious problem. This paper describes a new hash function, presents the properties obtained for large data sets, and discusses validity of the reconstructed surface. Experimental results proved theoretical considerations and advantages of hash function use for mesh reconstruction.
Trends in Materials Science for Ligament Reconstruction.
Sava, Oana Roxana; Sava, Daniel Florin; Radulescu, Marius; Albu, Madalina Georgiana; Ficai, Denisa; Veloz-Castillo, Maria Fernanda; Mendez-Rojas, Miguel Angel; Ficai, Anton
2017-01-01
The number of ligament injuries increases every year and concomitantly the need for materials or systems that can reconstruct the ligament. Limitations imposed by autografts and allografts in ligament reconstruction together with the advances in materials science and biology have attracted a lot of interest for developing systems and materials for ligament replacement or reconstruction. This review intends to synthesize the major steps taken in the development of polymer-based materials for anterior cruciate ligament, their advantages and drawbacks and the results of different in vitro and in vivo tests. Until present, there is no successful polymer system for ligament reconstruction implanted in humans. The developing field of synthetic polymers for ligament reconstruction still has a lot of potential. In addition, several nano-structured materials, made of nanofibers or in the form of ceramic/polymeric nanocomposites, are attracting the interest of several groups due to their potential use as engineered scaffolds that mimic the native environment of cells, increasing the chances for tissue regeneration. Here, we review the last 15 years of literature in order to obtain a better understanding on the state-of-the-art that includes the usage of nano- and poly-meric materials for ligament reconstruction, and to draw perspectives on the future development of the field.
Forensic Facial Reconstruction: The Final Frontier
Gupta, Vineeta; Vij, Hitesh; Vij, Ruchieka; Tyagi, Nutan
2015-01-01
Forensic facial reconstruction can be used to identify unknown human remains when other techniques fail. Through this article, we attempt to review the different methods of facial reconstruction reported in literature. There are several techniques of doing facial reconstruction, which vary from two dimensional drawings to three dimensional clay models. With the advancement in 3D technology, a rapid, efficient and cost effective computerized 3D forensic facial reconstruction method has been developed which has brought down the degree of error previously encountered. There are several methods of manual facial reconstruction but the combination Manchester method has been reported to be the best and most accurate method for the positive recognition of an individual. Recognition allows the involved government agencies to make a list of suspected victims’. This list can then be narrowed down and a positive identification may be given by the more conventional method of forensic medicine. Facial reconstruction allows visual identification by the individual’s family and associates to become easy and more definite. PMID:26501035
Antarctic station-based seasonal pressure reconstructions since 1905: 1. Reconstruction evaluation
NASA Astrophysics Data System (ADS)
Fogt, Ryan L.; Goergens, Chad A.; Jones, Megan E.; Witte, Grant A.; Lee, Ming Yueng; Jones, Julie M.
2016-03-01
Seasonal mean Antarctic pressures at 17 stations are reconstructed based on the method of principal component regression, employing midlatitude pressure data as predictors. Several reconstruction methods were performed in order to assess the stability and reliability of the reconstructions obtained, including performing the reconstructions over a shorter 30 year window and withholding the remaining data for an independent validation. Generally, there were small differences between the various approaches, but typically reconstructions conducted on data with the trends still present and over the full period of observations achieved the highest skill. Seasonally, reconstruction skill was high in austral summer across the entire Antarctic continent. Reconstructions that employed gridded pressure data over oceans as well as the observations (here termed "pseudoreconstructions") also performed remarkably well in austral winter. Spatially, the reconstruction skill was highest near the Antarctic Peninsula in all seasons, and weakest in coastal East Antarctica and the Antarctic Interior during austral spring and autumn; the spatial variability of the skill in part reflects the distance to the nearest midlatitude predictor. Nonetheless, for nearly all seasons and locations the observed trends since 1957 were well captured by the reconstructions, as was the low-frequency decadal-scale variability. These results suggest Antarctic pressure observations can be extended throughout the twentieth century with high confidence, especially in summer, allowing for a more precise understanding of the role and magnitude of natural atmospheric circulation variability across Antarctica.
Family Reconstruction: The Family within-a Group Experience.
ERIC Educational Resources Information Center
Satir, Virginia; And Others
1988-01-01
Presents Virginia Satir's Family Reconstruction, a group therapy experience that blends and extends her 1982 process therapy and 1983 conjoint family therapy approaches. Describes the family reconstruction process, the review of family reconstruction data in the pregroup interview, the family reconstruction process in the counseling group, and the…
Reconstruction of 3D angiography data using the algebraic reconstruction technique (ART)
NASA Astrophysics Data System (ADS)
Hampton, Carnell J.; Hemler, Paul F.
2001-07-01
Three-dimensional angiographic reconstrcution has emerged as an alternative to the traditional depiction of aneurysm angioarchitecture provided by 2-D perspective projections acquired by digital subtraction angiography (DSA) and fluoroscopy. One clinical application of research involving 3-D angiographic reconstruction is intraoperative localization and visualization during aneurysm embolization procedures. For this procedure, reconstruction quality is important for the 3-D reconstruction of anatomy as well as for the reconstrucution of intraaneurysm coils imaged endovascularly and subsequently rendered within an existing 3-D anatomic representation. Rotational angiography involves the acquisition of a series of 2-D, cone-beam projections of intracranial anatomy by a rotating x-ray gantry following a single injection of contrast media. Our investigation focuses on the practicality of using methods that employ algebraic reconstruction techniques (ART) to reconstruct 3-D data from 2-D cone-beam projections acquired using rotational angiography during embolization procedures. Important to our investigation are issues that arise within the implementation of the projection, correction and backprojection steps of the reconstruction algorithm that affect reconstruction quality. Several methods are discussed to perform accurate voxel grid projection and backprojection. Various parameters of the reconstruction algorithm implementation are also investigated. Preliminary results indicating that quality 3-D reconstructions from 2-D projections of synthetic volumes are presented. Further modifications to our implementation hold the promise of achieving accurate reconstruction results with a lower computation cost than the algorithm implemention used for this study. We have concluded that methods to extend the traditional ART algorithm for cone-beam projection acquisition produce quality 3-D reconstructions.