561 research outputs found

    Design and evaluation of an integrated software platform for optimization of reinforced concrete structures using evolutionary algorithms

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    Die vorliegende Arbeit verfolgt das Ziel, ein skalierbares und flexibles Softwaresystem zu entwerfen, das durch Anwendung unterschiedlicher Methoden der kĂŒnstlichen Intelligenz ermöglicht, den konzeptuellen und detaillierten Entwurf von komplexen Stahlbeton-Tragwerken zu optimieren. Die Evaluierung der entwickelten Konzepte und prototypischen Software-Tools erfolgt anhand von 3D-Modellen von Stahlbeton-HochhĂ€usern. Ein wesentlicher Beitrag der vorliegenden Arbeit liegt in der inhaltlichen Entkopplung komplexer Optimierungs-, Modellierungs- und Bewertungsverfahren von deren softwaretechnischen Implementierung. Die dadurch erreichte Anpassbarkeit sĂ€mtlicher Stufen des Optimierungsprozesses erschließt dem Anwender ein wesentlich breiteres Einsatzspektrum, als dies durch ĂŒbliche, auf spezifische Problemstellungen zugeschnittene Optimierungssysteme möglich ist.The goal of this work is the design of a scalable and flexible software system which supports optimization of the conceptual and detailed design of reinforced concrete structures using methods of artificial intelligence. The evaluation of the developed concepts and prototypic software tools uses three dimensional models of high rise buildings. One of the main advantages of the developed approach is the decoupling of komplex systems for optimization, modeling and assessment from the software implementation. This allows a high degree of adaptability in all stages of the optimization process, which opens a broader application range compared to optimization systems dedicated to certain optimization problems

    The Role of Educational Technology and Motivation in Increasing Flow and Time-On-Task to Enhance Learning

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    Technology plays an increasing role in college courses. Student experiences and outcomes may be significantly altered by high-tech course presentation and flexible formats. Models from psychology, such as Csikszentmihalyi\u27s flow theory are useful for understanding quality of experience. Dweck\u27s motivation theory explains why some students may not experience the flow state during school work. The purposes of this study were to: 1) Determine if students in technology-enhanced courses differ from other students on the experience of flow, 2) Test the relationship between flow, motivation orientation, and time-on-task, and 3) Test the relationship between motivation orientation, time-on-task, and student outcomes. Forty college students were randomly selected from four technology-enhanced and four control courses at Portland State University. Participants carried a two-way pager for eight days and responded with their activity when paged. Participants also completed a flow questionnaire and motivation questionnaire. No significant differences were found for the conditions of flow between technology-enhanced and control courses. Two linear regressions were used to test the relationship between the conditions of flow, motivation orientation, and time-on-task. The model for time-on-task for attending class was significant at p=.032; as goal clarity increased and/or as the balance of challenges and skills increased, time-on-task increased. Zero-order correlations for time-on-task for studying showed that as learning goals and/or feedback clarity increased, studying increased. Eight multiple linear regressions tested relationships between conditions for flow, motivation orientation, and results of flow. The models for concentration while studying and attending class were both significant. For attending class, increased learning goals were related to increased concentration. Increased learning goals and increased performance goals were related to increased concentration while studying. Many of these results are consistent with previous research on flow, motivation, and student outcomes. While there were no differences found between technology-enhanced and control courses, technology contains many tools which may positively influence improved student outcomes

    Soluble triggering receptor expressed on myeloid cells (sTREM-1) in der bronchoalveolÀren Lavage: diagnostischer Wert bei polytraumatisierten Patienten auf der Intensivstation : eine prospektive Studie

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    Einleitung: Schwer verletzte Patienten nach Trauma (ISS > 16) sind hĂ€ufig in Folge der Verletzungen ĂŒber mehrere Tage beatmet. 40% dieser Patienten weisen eine Lungenkontusion auf. Mit zunehmender Beatmungsdauer steigt das Risiko einer Ventilator-assoziierten Pneumonie (VAP). Zeitgleich findet eine Reparation des Lungengewebes statt. Eine zeitnahe antiinfektive Therapie bei Verdacht auf eine VAP zu initiieren ist schwierig. Derzeit existiert kein validierter Parameter oder Score, der eine sichere Diskriminierung zwischen Infektion und Inflammation zulĂ€sst. Triggering receptor on myeloid cells (TREM-1) ist ein Rezeptor des angeborenen Immunsystems und wurde im Jahr 2000 erstmalig beschrieben. Sein löslicher Anteil, sTREM-1, ist in der bronchoalveolĂ€ren Lavage (BAL) bei Patienten mit Pneumonie signifikant erhöht (> 200pg/ml). Es liegen keine Daten zu sTREM-1 bei Patienten nach Lungenkontusion vor. Unklar ist, ob sTREM-1 als Pneumonie-Marker nach Lungenkontusion geeignet ist. Material & Methoden: Nach Zustimmung der Ethikkommission und Einwilligung durch einen Angehörigen wurden prospektiv 42 Patienten mit Thoraxtrauma rekrutiert. Am ersten (im Median 15h nach dem Trauma) und an den Behandlungstagen zwei, drei, fĂŒnf, sechs und sieben wurden bei allen Patienten ĂŒber den Tubus mit einem Aero-Jet Katheter BAL (20ml SpĂŒlung) gewonnen und zeitgleich Serumproben entnommen. Die Messung der sTREM-1-Konzentration erfolgte mittels Sandwich-ELISA in Doppelbestimmung (Quantikine sTREM-1 Immunoassay; Firma R&D Systems). Die Serum-Konzentrationen der Interleukine (IL) 6 und 10 sowie des Lipopolysaccharid bindenden Proteins (LBP) wurden mittels ImmuliteÂź bestimmt. Die Diagnose Pneumonie wurde retrospektiv mittels Clinical Pulmonary Infection Score (CPIS) gestellt: CPIS > 6 Pneumonie, ≤ 6 keine Pneumonie. Ergebnisse & Diskussion: 15 Stunden nach Trauma wurde der sTREM-1 Spiegel in der BAL, bei im Verlauf pulmonal klinisch unauffĂ€lligen Patienten, im Median mit 219pg/ml bestimmt. Im Weiteren stieg sTREM-1 im Median nach 24h auf 575pg/ml an und zeigte Ă€hnliche Konzentrationen im Beobachtungszeitraum. Der Schweregrad der Lungenkontusion korreliert mit der Höhe des sTREM-1-Spiegels in der BAL 40h nach Trauma. Patienten mit schwerer Lungenkontusion (im Median 2240pg/ml) haben signifikant höhere Werte gegenĂŒber Patienten ohne Kontusion (Median 217pg/ml), oder geringer Kontusion (Median 339pg/ml). Am Tag der Diagnosestellung Pneumonie (CPIS > 6, n= 9) zeigten die betroffenen Patienten einen signifikant erhöhten sTREM-1-Spiegel in der BAL (Median 2145pg/ml, p 6 keine Antiinfektiva. In der Konsequenz könnte eine Kombination aus IL-6 und LBP im Serum, sTREM-1 in der BAL und klinischen Parameter des CPIS eine sensitive und spezifische Entscheidungshilfe fĂŒr eine antiinfektive Therapie bei Polytrauma und Verdacht auf eine VAP werden.Introduction: Severely injured trauma patients (ISS > 16) are often mechanically ventilated for several days. 40% of them show a contusion of the lungs. Prolonged mechanical ventilation results in an increased risk for ventilator associated pneumonia (VAP). At the same time healing of lung tissue takes place. This circumstance makes it difficult to initiate a timely antiinfective therapy when VAP is suspected. At present no validated parameter or score exists, that allows a definitive discrimination between infection and inflammation. Triggering receptor on myeloid cells (TREM-1) is a receptor of the innate immune response system, described first in 2000. Its soluble part, sTREM-1, is significantly increased in the bronchoalveolar lavage (BAL) samples of patients with pneumonia (> 200pg/ml). No data regarding about sTREM-1 in patients who suffered lung contusion. As a consequence it is unclear whether sTREM-1 is a suitable marker for pneumonia in lung contusion. Material and methods: After approval of the local ethics committee and informed consent of the patients legal guardian, we enrolled 42 patients with thoracic trauma. On the first (Median 15 hours after trauma) and on the 2nd, 3rd, 5th, 6th and 7th day of ICU-treatment we collected BAL with an Aero-Jet catheter via the breathing tube (20 ml rinsing) and serum-probes at the same time. sTREM-1 levels were determined by enzyme-linked immunosorbent assay with repeated measurements (Quantikine sTREM-1 Immunoassay; R&D Systems). Serum-levels of interleukin (IL) 6 and 10 as well as lipopolysaccharid binding protein (LBP) were quantified by ImmuliteÂź (Siemens Medical Solution Diagnostics). The diagnosis of pneumonia was confirmed retrospectively by the Clinical Pulmonary Infection score (CPIS): Pneumonia = CPIS > 6; no pneumonia = CPIS ≤ 6. Results and discussion: 15 hours after trauma the median sTREM-1 level in the BAL samples, in patients with clinical unremarkable course, was determined at 219pg/ml. Subsequently, after another 24h the median sTREM-1 level increased to a concentration of 575pg/ml and showed a similar concentration during the entire observation period. Patients with severe lung contusion showed increased sTREM-1 concentrations in BAL samples. The severity of lung contusion correlates with the amount of sTREM-1 level in BAL samples 40h after trauma. sTREM-1 concentration in patients with severe lung contusion (median 2240pg/ml) was significantly higher compared to patients without contusion (median 217pg/ml) or mild contusion (339pg/ml). On the day of diagnosis of pneumonia (CPIS > 6; n = 9), patients involved showed a significantly increased sTREM-1 level in the BAL sample (median 2145pg/ml; p 6. Consequently we feel that a combination of IL-6 and LBP in serum, sTREM-1 in BAL and CPIS clinical parameters can be helpful in making an informed decision for an antiinfective therapy in patients after polytrauma with suspected VAP

    Comparison of static GNSS data-processing softwares

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    Bakalaureusetöö Geodeesia, maakorralduse ja kinnisvara planeerimise Ă”ppekavalTöö eesmĂ€rk oli vĂ”rrelda programmide RTKLIB ja Trimble Business Center (TBC) staatiliste GNSS andmete jĂ€reltöötluse erinevusi. Andmetöötluses kasutati viies punktis lĂ€bi viidud staatilise GNSS mÔÔtmise andmeid. Baasjaamana kasutati TĂ”ravere GNSS pĂŒsijaama, mille andmed laeti alla EPN kodulehelt. Staatiliste GNSS mÔÔtmiste kestvus oli ĂŒks tund. MÔÔtmisel kasutati ainult GPS satelliite, mille tĂ”usunurk ĂŒletas 10°. MĂ”lema tarkvaraga töödeldi samu andmeid. RTKLIB andmetöötlus tehti lĂ€bi Static ja PPP-Static viisidel. Tulemustest vĂ”rreldi pĂ”hja, ida ja kĂ”rguse suunalisi standardhĂ€lbeid, L-EST97 koordinaate ja geodeetilisi kĂ”rgusi. Suurimad standardhĂ€lbed saadi kasutades RTKLIB PPP-Static viisi ja vĂ€ikseimad standardhĂ€lbed kasutades Trimble Business Centerit . TBC ja RTKLIB Static standardhĂ€lbed olid kĂ”ik vĂ€iksemad (kuni ±4 cm) ja PPP-Static standardhĂ€lved olid kuni ±15cm. Static ja PPP-Static koordinaatide ja kĂ”rguste erinevuste ruutkeskmised olid X- koordinaadil ±0,524 m, Y- koordinaadil ±0,612 m ja geodeetilisel kĂ”rgusel ±0,167 m. Static ja TBC koordinaatide vĂ”rdlusel on nĂ€ha, et ĂŒhel punktil on sees jĂ€me viga. Koos jĂ€meda veaga on koordinaatide ja kĂ”rguste erinevuste ruutkeskmine Xkoordinaadil ±0,147 m, Y- koordinaadil ±0,262 m ja geodeetilisel kĂ”rgusel ±0,162 m. Ilma jĂ€meda veata on erinevus X- koordinaadil ±0,017 m, Y- koordinaadil ±0,019 m ja geodeetilisel kĂ”rgusel ±0,059 m. RTKLIB Static ja TBC sobivad mĂ”lemad staatiliste GNSS andmete töötluseks, kuid TBC on igapĂ€evakasuThe goal of this paper was to compare two softwares RTKLIB and Trimble Business Center (TBC) and to evaluate the differences in their static GNSS data post-processing. The static GNSS data used in post-processing was gathered by conducting five static GNSS measurements on five different points. TĂ”ravere GNSS reference station was used as the base station and the measurement data from that station was downloaded from the EPN website. Each conducted measurement lasted for an hour. Only satellites with elevation mask of 10° or higher from the GPS constellation were used. Both softwares were given identical measurement data to process. Both Static and PPP-Static methods were used in post-processing with RTKLIB. Out of the results north, east and height standard deviations, calculated L-EST97 coordinates and geodetic heights were compared. The biggest standard deviations were gotten from PPP-Static and the smallest from TBC. TBC and Static standard deviations were all smaller than ±4 cm and PPP-Static's standard deviations were up to ±15 cm. The root mean square (RMS) differences between Static and PPP-Static coordinates and heights was ±0,524 m for the X- coordinate, ±0,612 m for the Y coordinate and ±0,167 m for height. From comparing the Static and TBC L-EST97 coordinates and heights one can see that the differences from one measurement is too great to not be an error. If the error is included then the Static and TBC coordinate and height difference RMS is ±0,147 m for the X, ±0,262 m for the Y and ±0,162 m for height. But if the errorneous point is not included the RMS drops down to ±0,017 m for X, ±0,019 for the Y and ±0,059 m for geodetic height. RTKLIB Static and TBC are both suitable to use to process static GNSS data but TBC provides more comfort for everyday use and RTKLIB lets the user change more options during post-processing

    Multidiffusive Konvektion mit Koagulation und Breakup : Numerische Untersuchungen zur Erweiterung der thermo-diffusiv-sedimentĂ€ren Konvektion auf verĂ€nderliche PartikelgrĂ¶ĂŸen

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    Gegenstand dieser Arbeit ist die Konzeption, Entwicklung und Untersuchung eines neuen Ansatzes zum Studium thermo-diffusiv-sedimentĂ€rer Konvektionssysteme fĂŒr verschiedene PartikelgrĂ¶ĂŸenklassen mit integrierten Koagulations- und Breakup-Prozessen. Thermo-diffusiv-sedimentĂ€re Konvektionssysteme (TDSC) beschreiben die kriechende Strömung eines Suspensats aus einem Fluid mit festen Partikeln. Vorhergehende Studien von TDSC haben gezeigt, daß die sich einstellenden SystemzustĂ€nde stark von der PartikelgrĂ¶ĂŸe abhĂ€ngen. Die Erweiterung des TDSC-Systems auf unterschiedliche PartikelgrĂ¶ĂŸen ermöglicht die Analyse dieser AbhĂ€ngigkeit. Die Implementierung eines Koagulations- und eines Breakup-Prozesses gestattet es, dynamische VerĂ€nderungen der PartikelgrĂ¶ĂŸenverteilung zu simulieren. Bei den Untersuchungen konnte eine bislang in Modellen nicht bekannte Form episodischen Systemverhaltens nachgewiesen werden. Diese kann anhand des zwischenzeitlich vollstĂ€ndigen Absterbens der Konvektion eindeutig von den pulsatorischen ZustĂ€nden unterschieden werden. Episodischen ZustĂ€nde sind somit durch abwechselnde Phasen von relativ kurzen konvektiven und relativ langen Phasen nicht-konvektiven Systemverhaltens gekennzeichnet. WĂ€hrend der letzteren wird die PartikelgrĂ¶ĂŸenverteilung durch die Koagulations- und Breakup-Prozesse in einer Weise geĂ€ndert, die das Einsetzen der Konvektion auslöst. Das episodische Systemverhalten durchlĂ€uft daher aus systemtheoretischer Sicht qualitativ verschiedene Phasen, wĂ€hrend jene der pulsatorischen Konvektion sich lediglich quantitativ unterscheiden. Die beobachteten episodischen SystemzustĂ€nde können als eine Folge unterschiedlicher Zeitskalen von Koagulations- und Breakup-Prozessen auf der einen Seite und Fließprozessen auf der anderen Seite aufgefaßt werden. Sie konnten nicht nur fĂŒr verschiedene Breakup-Mechanismen, sondern auch fĂŒr eine Variation der Koagulationswahrscheinlichkeit ĂŒber mehrere GrĂ¶ĂŸenordnungen nachgewiesen werden. Unter den Breakup-Mechanismen haben jene mit einer stĂ€rker als proportional zum Volumen wachsenden Zerfallswahrscheinlichkeit dem Konvektionssystem die meisten Entfaltungsmöglichkeiten eröffnet. Die Koagulationswahrscheinlichkeit selbst zeigt eine der Spreizung der Sinkgeschwindigkeitsskala vergleichbare Wirkung. Das erweiterte Konvektionsmodell ermöglicht es, Mikro- und Makroskala der AusprĂ€gung von SystemzustĂ€nden eingehender zu studieren. Dazu galt es eine Kombination aus einer diskreten mit einer Kontinuumsbeschreibung der Konzentration unter Verwendung von Partikelanzahldichten zu entwickeln. Das Vorhaben einer natĂŒrlichen Erweiterung der Konzentrationsrandwertbedingungen des TDSC-Modells mußte verworfen werden, da diese zumeist den Freiheitsgrad der Anpassung des PartikelgrĂ¶ĂŸenspektrums aufhebt. Die Erweiterung des TDSC-Modells auf verĂ€nderliche PartikelgrĂ¶ĂŸen verbessert das VerstĂ€ndnis des Strukturbildungsprozesses der Schichtbildung. Es ist gelungen, ein Schema der prinzipiellen Abfolge der SystemzustĂ€nde unter Erhöhung der Sedimentationsgeschwindigkeit zu erstellen. Neben der Ausbildung eines neuen Systemzustandes ließen sich auch verĂ€nderte Mechanismen der Entstehung bereits bekannter SystemzustĂ€nde beobachten. Die Entwicklung bimodaler PartikelgrĂ¶ĂŸenverteilungen und damit die Bevorzugung zweier relativ unterschiedlicher PartikelgrĂ¶ĂŸen konnte nachgewiesen werden. Damit war es möglich, zu einem vertieften VerstĂ€ndnis der Konvektionsströmungen im Erdinneren beizutragen.Multidiffusive Convection with Coagulation and Break-up - Numerical Investigations of a Thermo Diffusive Sedimentary Convection Model with Variable Particle Sizes This thesis reports on the conception, development and evaluation of an own, new approach to study thermo diffusive sedimentary convection systems for various particle sizes with integrated coagulation and break-up processes. Thermo diffusive sedimentary convection (TDSC) systems describe the creeping flow of a suspension of a fluid with solid particles. Preceding studies of TDSC systems had shown the strong dependence of the resulting system states on the particle size. Extending the TDSC system to different particle sizes permits the analysis of this dependence. Moreover, the implementation of coagulation and break-up processes simulates dynamic changes of the particle size distribution. We could examine an up to now in convection models unknown form of episodic system behaviour, which can be clearly separated from pulsatoric states by the temporary complete disappearance of convection. These newly discovered episodic states can be characterised through alternate periods of relatively short convective and considerably longer periods of non-convective system behaviour. During the non-convective phases, the particle size distribution is changed by coagulation and break-up processes in a way which causes triggering of convection. In a system-theoretical view, episodic system behaviour passes through qualitatively different phases, whereas phases of pulsatoric convection differ merely quantitatively. The observed episodic system states can be understood as a consequence of different time scales of coagulation, break-up, and fluid flow processes. They can be proved not only for some break-up mechanisms but also for the variation of the coagulation probability on several orders of magnitude. Break-up mechanisms whose decay probabilities grow stronger than proportional with the volume are supplying most development possibilities to the convection system. Analysing the parameter dependence of the system states, we could reveal that the probability of coagulation has a comparable effect to the spreading of the scale of sink rate. The enhanced convection model makes it possible to examine micro and macro scales of the development of system states in more detail. This was possible by the combination of a discrete with a continuous description of concentration by the use of density numbers of particles. The initial concept of a natural extension of the concentration boundary conditions of the original TDSC model had to be abandoned because otherwise the additionally enabled degree of freedom through adaption of the particle size distribution would have been annihilated. The extension of the TDSC model towards variable particle sizes improves the understanding of the structure forming process of the sedimentary layering. We were able to build a scheme of the principal sequence of system states under an increase of settling rate. Apart from the formation of a new system state we could also detect modified mechanisms of emergence of well-known system states. The development of bimodal particle size distributions and thus the simultaneous preference of two relatively different particle sizes could be proved. For this reason we were able to contribute to improving the understanding of convective flows in the interior of the earth

    Nitrosopersulfide (SSNO(-)) targets the Keap-1/Nrf2 redox system.

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    Nitric oxide (NO), hydrogen sulfide and polysulfides have been proposed to contribute to redox signaling by activating the Keap-1/Nrf2 stress response system. Nitrosopersulfide (SSNO(-)) recently emerged as a bioactive product of the chemical interaction of NO or nitrosothiols with sulfide; upon decomposition it generates polysulfides and free NO, triggering the activation of soluble guanylate cyclase, inducing blood vessel relaxation in vitro and lowering blood pressure in vivo. Whether SSNO(-) itself interacts with the Keap-1/Nrf2 system is unknown. We therefore sought to investigate the ability of SSNO(-) to activate Nrf2-dependent processes in human vascular endothelial cells, and to compare the pharmacological effects of SSNO(-) with those of its precursors NO and sulfide at multiple levels of target engagement. We here demonstrate that SSNO(-) strongly increases Nrf2 nuclear levels, Nrf2-binding activity and transactivation activity, thereby increasing mRNA expression of Hmox-1, the gene encoding for heme oxygenase 1, without adversely affecting cell viability. Under all conditions, SSNO(-) appeared to be more potent than its parent compounds, NO and sulfide. SSNO(-)-induced Nrf2 transactivation activity was abrogated by either NO scavenging with cPTIO or inhibition of thiol sulfuration by high concentrations of cysteine, implying a role for both persulfides/polysulfides and NO in SSNO(-) mediated Nrf2 activation. Taken together, our studies demonstrate that the Keap-1/Nrf2 redox system is a biological target of SSNO(-), enriching the portfolio of bioactivity of this vasoactive molecule to also engage in the regulation of redox signaling processes. The latter suggests a possible role as messenger and/or mediator in cellular sensing and adaptations processes
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