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Astronomische Nachrichten 11/2012; 333:816. · 1.01 Impact Factor
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W Schmidt,
O Lühe,
R Volkmer,
C Denker,
S ~K Solanki,
H Balthasar,
N Bello Gonzalez,
T Berkefeld,
M Collados, A Fischer, [......],
H Nicklas,
E Popow,
K ~G Puschmann,
D Schmidt,
M Sigwarth,
M Sobotka,
D Soltau,
J Staude,
K ~G Strassmeier,
T ~A Waldmann
Astronomische Nachrichten 11/2012; 333:796. · 1.01 Impact Factor
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ABSTRACT: In this study, a thermo-mechanical model was utilized to investigate the effects of welding parameters on the distribution
of residual stresses in dissimilar TIG welds of low carbon and ferritic stainless steels. To solve the governing thermal and
mechanical problems, a finite element program, ANSYS, was employed while the different aspects such as welding sequence and
dilution were considered in the numerical solution. To validate the predictions, the model results were compared with the
residual stresses measured by X-ray diffraction technique and a reasonable agreement was found. The results show that the
magnitude of tensile residual stresses decrease as the welding current increases while lower residual stresses are produced
in the longer samples. In addition, the magnitudes of residual stresses significantly decrease when a symmetric welding sequence
is employed especially for the carbon steel part with the higher yield strength.
Journal of Materials Science 05/2012; 46(9):3225-3232. · 2.02 Impact Factor
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BJA British Journal of Anaesthesia 05/2012; 108(5):882. · 4.24 Impact Factor
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ABSTRACT: Einleitung. Die Behandlung schwersterkrankter Patienten stellt eine große medizinische und menschliche Herausforderung dar. Ziel der
Studie war die Ermittlung der Mortalität von Patienten mit langdauerndem intensivmedizinischem Aufenthalt sowie die Bestimmung
des somatischen, psychischen und sozialen Status der Überlebenden.
Methoden. Die Daten aller Patienten, die mindestens 30 Tage auf einer chirurgischen Intensivstation behandelt waren, wurden retrospektiv
nach Alter, Geschlecht, Art der Grunderkrankung, APACHE-II-Score, ISS, Vorerkrankungen, Behandlungsmaßnahmen, Komplikationen,
Art und Ausmaß der Störungen von Organsystemen und Mortalität analysiert. Die Überlebenden wurden nach 35±14 Monaten nachuntersucht.
Von ihnen wurden somatische, psychische und soziale Parameter erhoben.
Ergebnisse. Es wurden die Daten von 101 Patienten analysiert (m/w: 78/23, mittleres Alter: 49,9±18,2 Jahre, mittlere Liegedauer: 57±37
Tage, Anteil Traumapatienten: 46%). 31 Patienten verstarben auf der Intensivstation. Bis zur Nachuntersuchung verstarben weitere
24 Patienten. Damit fand sich eine Gesamtmortalität von 55%. Alter, Art der Grunderkrankung und Ausmaß des Multiorganversagens
beeinflussten das Versterben auf der Intensivstation. Die Mortalität nach Entlassung zeigte eine Abhängigkeit von Alter, Anzahl
der Vorerkrankungen und der Grunderkrankung. Von den überlebenden 46 Patienten konnten 41 (89%) nachuntersucht werden. Knapp
die Hälfte wiesen in allen Funktionsbereichen keine oder nur geringe Einschränkungen auf, bei einem Drittel fanden sich schwerste
Beeinträchtigungen. Traumapatienten zeigten die geringste Mortalität aber schlechtere Rehabilitationsergebnisse.
Schlussfolgerungen. Einerseits besteht nach Langzeitintensivtherapie eine deutlich erhöhte Mortalität im Vergleich zu einer durchschnittlichen
intensivmedizinischen Behandlung. Andererseits können die überlebenden Patienten nach überstandener Akutphase in der Mehrheit
erfolgreich somatisch, psychisch und sozial rehabilitiert werden. Deren Langzeitergebnis ist mit dem nach durchschnittlicher
intensivmedizinischer Behandlung vergleichbar. Die Behandlungsergebnisse ermutigen zum konsequenten Einsatz aller medizinischen
Möglichkeiten.
Objective. The treatment of severely ill patients remains a medical and human challenge. The aim of the study was to determine the survival
rate of patients with prolonged intensive care unit (ICU) treatment. Additionally, the somatic, psychological, and social
sequelae of the survivors should be determined.
Methods. Data of all patients who stayed for at least 30 consecutive days on a surgical ICU were evaluated with respect to age, sex,
diagnosis on admission, APACHE II-Score, ISS, pre-existing diseases, therapeutic procedures, complications, organ dysfunctions,
and mortality. The survivors passed a follow-up examination after 35±14 months. This included somatic, psychological, and
social parameters.
Results. Data of 101 patients were analysed (m/f: 78/23, mean age: 49.9±18.2 years, mean stay on ICU: 57±37 days, trauma patients:
46%). 31 subjects died on the ICU. Until the follow-up, another 24 patients deceased. Thus, the total mortality rose to 55%.
Age, diagnosis on admission and severity of organ failure influenced the ICU mortality. Concerning the mortality after discharge,
age, pre-existing morbidity and diagnosis on admission affected the outcome. 41 of the remaining 46 patients (89%) underwent
the follow-up. Nearly half of them showed no or minor signs of impairment in any of the investigated areas. One third had
severe handicaps. Trauma patients had the lowest mortality rates but showed worse results in rehabilitation.
Conclusions. The mortality after prolonged ICU-treatment is substantially higher compared to average ICU patients. However, having survived
the acute phase of the illness, successful rehabilitation in somatic, psychic as well as social terms could be performed to
a considerable extent. This outcome is comparable to the one of other ICU populations. The results encourage to a consequent
use of all medical options.
Der Unfallchirurg 04/2012; 105(5):423-430. · 0.61 Impact Factor
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ABSTRACT: The neural network method, a relatively new method in reverse engineering (RE), has the potential to reconstruct 3D models
accurately and fast. A neural network (NN) is a set of interconnected neurons, in which each neuron is capable of making autonomous
arithmetic and geometric calculations. Moreover, each neuron is affected by its surrounding neurons through the structure
of the network.
This work proposes a new approach that utilizes growing neural gas neural network (GNG NN) techniques to reconstruct a triangular
manifold mesh. This method has the advantage of reconstructing the surface of an n-genus freeform object without a priori
knowledge regarding the original object, its topology or its shape. The resulting mesh can be improved by extending the MGNG
into an adaptive algorithm. The proposed method was also extended for micro-structure modeling. The feasibility of the proposed
method is demonstrated on several examples of freeform objects with complex topologies.
The Visual Computer 04/2012; 24(4):295-302. · 0.58 Impact Factor
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ABSTRACT: During the development of an embryo into a juvenile, the physiology and behavior of a fish change greatly, affecting exposure to and uptake of environmental pollutants. Based on experimental data with sole (Solea solea), an existing bioaccumulation model was adapted and validated to calculate the development of concentrations of persistent organic pollutants in the tissue of developing fish. Simulation revealed that toxic tissue concentrations of pollutants with log octanol-water partition ratio (K(OW)) > 5 peak at the moment when the larvae become free-feeding, when the lipid reserves are depleted. This may explain the delayed effects observed in fish early-life-stage experiments with exposed eggs. In the field, eggs can be exposed through maternal transfer to adult pollutant tissue concentrations, which will increase in the larva to peak tissue concentrations, exceeding those of the adult fish. The results demonstrate the risk of underestimating the effects of lipophilic persistent organic pollutants with log K(OW) > 5 in short-term, early-life-stage fish tests and underscore the importance of maternal transfer as an exposure route in the field situation.
Environmental Toxicology and Chemistry 04/2012; 31(6):1381-90. · 2.81 Impact Factor
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M. Aeschlimann,
M. Bauer,
D. Bayer,
T. Brixner,
S. Cunovic, A. Fischer,
P. Melchior,
W. Pfeiffer,
M. Rohmer,
C. Schneider,
C. Strüber,
P. Tuchscherer,
D.V. Voronine
New Journal of Physics 01/2012; 14:033030. · 4.18 Impact Factor
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ABSTRACT: To cope with the tremendous variations of writing styles encountered between different individuals, unconstrained automatic handwriting recognition systems need to be trained on large sets of labeled data. Traditionally, the training data has to be labeled manually, which is a laborious and costly process. Semi-supervised learning techniques offer methods to utilize unlabeled data, which can be obtained cheaply in large amounts in order, to reduce the need for labeled data. In this paper, we propose the use of Co-Training for improving the recognition accuracy of two weakly trained handwriting recognition systems. The first one is based on Recurrent Neural Networks while the second one is based on Hidden Markov Models. On the IAM off-line handwriting database we demonstrate a significant increase of the recognition accuracy can be achieved with Co-Training for single word recognition.
Document Analysis and Recognition (ICDAR), 2011 International Conference on; 10/2011
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ABSTRACT: Spotting keywords in handwritten documents without transcription is a valuable method as it allows one to search, index, and classify such documents. In this paper we show that keyword spotting based on bi-directional Long Short-Term Memory (BLSTM) recurrent neural nets can successfully be applied on online handwritten documents with non-text content. It even works without preprocessing steps such as text vs. non-text distinction and text line extraction. We also propose a modification that can improve the precision with little effort.
Document Analysis and Recognition (ICDAR), 2011 International Conference on; 10/2011
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ABSTRACT: We show experimentally as well as in simulation that the phase-sensitive superposition of different plasmonic modes leads to a spatially controllable enhancement of the near-field inside and in the vicinity of a metallic nanostructure. Multiphoton photoemission electron microscopy maps the local near-field distribution. By controlling the relative phase Θ between two orthogonally polarized light pulses the spatial distribution of the near-field is manipulated on the basis of the interference of the near-field modes. This demonstration of optical near-field control is corroborated by finite integral time domain calculations.
Phys. Rev. B. 06/2011; 83(23).
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ABSTRACT: Addressing applications such as high performance RF power amplifiers and DC/DC converters with high conversion efficiency we demonstrate a cost effective integration of a complementary medium voltage RF LDMOS module in a 0.25 μm base CMOS flow. The integration of the NLDMOS and PLDMOS transistors requires just three additional mask steps. The NLDMOS has an excellent large signal RF performance up to 6 GHz. Key RF performance figures at 1 dB gain compression are 20 dB gain, 35 % power added efficiency and 0.4 W/mm power density. First prototypes of fabricated 12 V DC/DC down converters and 6 GHz power amplifiers verify the excellent DC and RF performance of the devices.
Silicon Monolithic Integrated Circuits in RF Systems (SiRF), 2011 IEEE 11th Topical Meeting on; 02/2011
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ABSTRACT: For 77-GHz automotive radar applications, a monolithic frequency multiplier with a multiplication factor of 18 is presented. The main circuit of the multiplier chain consists of two frequency tripler and one doubler. Additionally interstage amplifiers and filters are integrated in a 200-GHz SiGe:C production technology. The output power is -1dBm for a wide input power range (-20dBm - +8 dBm) at room temperature and 76.5 GHz output frequency. The output power flatness is better than 2 dB for an output frequency range of 69 GHz to 80 GHz. The power consumption of the multiplier is 170mW at a single supply voltage of 3.3V.
Bipolar/BiCMOS Circuits and Technology Meeting (BCTM), 2010 IEEE; 11/2010
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ABSTRACT: This work presents some recent progresses in reliability assessment of electronic assemblies in automotive industry and shows how coupled numerical-experimental techniques can help us save time and reduce the cost of IC package qualification. In order to fulfill the continuous trends in miniaturization of the electronic devices together with the demands to shorten the time-to-market, it is essential to use virtual qualification methods with the simulation tools. One of the main concerns in electronic packages is their structural integrity during the fabrication, surface mount process, and service life. A prominent example of failure in electronic assemblies is the interface delamination between two dissimilar materials. This failure mode is accelerated when the polymeric materials absorb moisture from humid environments. Moisture results in degradation of the physical properties of polymers, induces additional deformation due to hygroscopic swelling, and more importantly, degrades the adhesion strength of the polymer to metal joints. This work provides conceptual understandings of the problem of moisture-driven interface delamination in plastic encapsulated microcircuits. In addition, it is shown how the developed method can enhance the material selection in order to improve the delamination resistance in the package and preserve the structural integrity.
Electronic System-Integration Technology Conference (ESTC), 2010 3rd; 10/2010
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Y Escabi,
L San Miguel,
T. Judd,
J Hertza,
J Nicholson,
W Schiff,
C Bell,
B Estes,
C Millikin,
P Shelton, [......],
D Wygant,
P Klonoff,
D Carone,
T O'Connor Pennuto,
A Kluck,
J Ball,
L Shahani,
J Thomspon,
A Bowles,
M Greiffenstein
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ABSTRACT: The evaluation of bilingual children is a complicated endeavor because there are various views of how bilingualism affects brain organization and functioning. Added to that is the challenge of determining language development of Hispanic children living in a monolingual Spanish-speaking home in a Spanish-speaking country, but mostly exposed to English language television programming and, in some cases, English language school curriculum. Our case will review the evaluation process of a 14-year-old Puerto Rican boy with previous diagnoses of expressive language disorder and Attention-deficit/Hyperactivity Disorder (ADHD). The neuropsychological evaluation revealed an IQ within the average range, with significant differences between the perceptual reasoning, verbal comprehension, and processing speed. The case will summarize performance in verbal, executive, and psycho-educational measures with a thorough review of his developmental history and the interpretation of these neuropsychological achievement and behavioral measures in light of other variables influencing his difficulties.
Archives of Clinical Neuropsychology 09/2010; 25(6):475-583. · 2.18 Impact Factor
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R. Volkmer,
O. von der Lühe,
C. Denker,
S.K. Solanki,
H. Balthasar,
T. Berkefeld,
P. Caligari,
M. Collados, A. Fischer,
C. Halbgewachs, [......],
A. Hofmann,
M. Klvaňa,
F. Kneer,
A. Lagg,
E. Popow,
D. Schmidt,
W. Schmidt,
M. Sobotka,
D. Soltau,
K.G. Strassmeier
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ABSTRACT: The integration and verification phase of the GREGOR telescope reached an important milestone with the installation of the interim 1 m SolarLite primary mirror. This was the first time that the entire light path had seen sunlight. Since then extensive testing of the telescope and its subsystems has been carried out. The integration and verification phase will culminate with the delivery and installation of the final 1.5 m Zerodur primary mirror in the summer of 2010. Observatory level tests and science verification will commence in the second half of 2010 and in 2011. This phase includes testing of the main optics, adaptive optics, cooling and pointing systems. In addition, assuming the viewpoint of a typical user, various observational modes of the GREGOR Fabry-Pérot Interferometer (GFPI), the Grating Infrared Spectrograph (GRIS), and high-speed camera systems will be tested to evaluate if they match the expectations and science requirements. This ensures that GREGOR will provide high-quality observations with its combination of (multi-conjugate) adaptive optics and advanced post-focus instruments. Routine observations are expected for 2012 (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Astronomische Nachrichten 05/2010; 331(6):624 - 627. · 1.01 Impact Factor
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ABSTRACT: Bones are composed of hierarchical bio-composite materials characterized by complex multiscale structural geometry and behaviour. Currently, there is great interest within the biomedical community in developing accurate non-invasive techniques for analysing bone micro-structure. We propose a new approach of multiscale finite element analysis of bone micro-structure which can provide physicians with a ‘digital magnifying glass’ providing a continuous bi-directional transition between macro- and micro-scales. In the macro-scale, the material appears to be smoother and more homogeneous. The zooming-in process reveals additional details and the heterogeneity of the material. In this paper we deal with the 2D geometric aspects, demonstrating the feasibility of the proposed method, using a multiscale domain-based geometric model.
Virtual and Physical Prototyping 03/2010; 5(1):33-43.
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ABSTRACT: A novel radar frontend for 77 GHz mid-range-radar (MRR) and short-range-radar (SRR) applications is presented. The radar sensor makes use of a Colpitts oscillator, frequency multipliers, and a transceive (TRX) mixer. A single sensor contains up to four channels using antenna arrays for angular detection relative to the sensor. The characterization of the integrated circuit's parameters has been carried out using a two-channel sensor with waveguide (WG) transitions. A radar measurement scenario has been realized using a four-channel sensor with a differential antenna array. All sensors have been implemented on off-the-shelf printed circuit board (PCB) substrate.
Silicon Monolithic Integrated Circuits in RF Systems (SiRF), 2010 Topical Meeting on; 02/2010
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ABSTRACT: Synthesizing of human motion is one of the challenges in humanoid robotics research. Interested in the construction of humanoid service robots exhibiting human-like movements research is following different ways. This paper is going along with the idea of determining the principles of human motor control in order to understand the generation of human motion. A computational framework based on an efficient technique combining motion capture with multibody systems and optimal control theory for large-scale dynamic analysis and synthesis of motion is presented. Experiments were performed for human pointing gestures and the framework was validated computing the optimal trajectories of minimum hand jerk, modified minimum hand jerk, minimum angle jerk and minimum torque change.
Humanoid Robots, 2009. Humanoids 2009. 9th IEEE-RAS International Conference on; 01/2010
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ABSTRACT: Building recognition systems for historical documents is a difficult task. Especially, when it comes to medieval scripts. The complexity is mainly affected by the poor quality and the small quantity of the data available. In this paper we apply an HMM based recognition system to medieval manuscripts from the 13th century written in Middle High German. The recognition system, which was originally developed for modern scripts, has been adapted to medieval scripts. Beside the data processing, one of the major challenges is to create a suitable language model. Because of the lack of appropriate independent text corpora for medieval languages, the language model has to be created on the base of a rather small number of manuscripts only. Due to the small size of the corpus, optimizing the language model parameters can quickly lead to the problem of overfitting. In this paper we describe a strategy to integrate all available information into the language model and to optimize the language model parameters without suffering from this problem.
Document Analysis and Recognition, 2009. ICDAR '09. 10th International Conference on; 08/2009
