Littérature scientifique sur le sujet « Duration matrix »

The objective of this study is the investigation of nanomechanical properties using nanoindentation of extruded and heat-treated Mg-Dy-Nd-Zn-Zr, with an emphasis on the transformation of long-period stacking-ordered (LPSO) phases. Solution heat treatment was performed with different heat treatment for durations on hot extruded Mg-Dy-Nd-Zn-Zr to monitor the transformation of LPSO phases, as well as to keep track of microstructural changes. The initial fine-grained microstructure, with blocky and lamellar LPSO structures within the matrix, first transformed into coarser grains with fewer LPSO lamellae, which then increased in amount again at higher annealing duration. The blocky LPSO phases, which have the highest hardness compared to the matrix grains with and without LPSO lamellae, consistently decrease in quantity, as so does the trend in their hardness value. The Mg matrix grains with LPSO lamellae show a lower hardness compared to the Mg matrix grains without or with a just few lamellar LPSO phases, and increase in quantity at long annealing durations. The overall hardness of the microstructure is essentially determined by the LPSO lamellae-containing grains and reaches a peak at 24 h. There is another peak found for the grain size values; however, this is at later annealing duration, at 72 h. The reduction in grain size towards longer annealing durations goes along with a reactivated formation of LPSO lamellae.

The probable route sets in the network diagram were calculated by adjacency matrix method, and based on the assumption that activity becoming the key obeyed 0-1 distribution, a probable route matrix was established. A random variable matrix was structed by monte carlo simulation under condition of activity time independent distribution. A matrix algorithm model was built by isolating activity times impact on activity becoming the key for the first time. This model with a simple and optimal algorithm avoided the computation complexity of network planning time parameter, to evaluate project duration risk rapidly and statistical analyze the probability of activity becoming the key and the influence degree of activity time fluctuation impacting on project duration, providing theoretical and data support for decisions. Empirical research on a tunnel engineering project verified its practicability and feasibility, providing a new powerful tool for assessing project duration risk in the network diagram quickly.

Effects of sea water immersion for palm fiber in relation to surface morphology, roughness and bonding between the fiber and sago matrix were observed. Duration of immersion varied in 1, 2, 3 and 4 weeks, and then dried at room temperature for 3 hours continued by oven at 80 °C for 6 hours. SEM and roughness arithmetic tests were applied to see surface morphology, roughness and bonding between fiber and the matrix. Result shows fiber morphology and roughness varies by the duration of immersion. The surface roughness increases as immersion continues along with fiber - matrix bonding improvement. The maximum duration of 4 weeks fiber immersion resulted in the best interlocking of matrix and fibers, as the slits between them disappear.

Random matrix theory (RMT) exploits the distribution of singular values of the inter-element response matrix (IRM). If multiple scattering dominates the propagation, the singular value distribution follows the quarter circle law. However, dominance of single scattering results in Henkel function behavior of the singular value distribution. In our previous work, we have shown that this can be exploited to estimate severity of bleomycin-induced fibrosis (measured by histology) in rodent lungs. We showed that E( x), the expected value of the singular value distribution, as well as the singular value with the highest probability, correlated significantly with histology scores. Here, we investigate the sensitivity of these metrics to the time window duration used for the Singular Value Decomposition of the IRM, which is performed in the frequency domain, using overlapping time windows. A linear transducer with a central frequency of 7.8 MHz and a Verasonics scanner were used to obtain IRMs in 24 rat lungs. Different degrees of pulmonary fibrosis were induced using bleomycin in 18 rats while 6 rats were left as controls. The IRMs were time-windowed with different duration of 2T, 4T, and 6T where T is the transmitted pulse period. E(x) and were evaluated for each time window duration for all rat lungs. For all time window durations significant correlations were observed between and E(x), and histology scores. Wilcoxon ranksum tests show that the distributions obtained for and E(x) are not affected by the time window duration.

Abstract Leg ulcers are a chronic manifestation of sickle-cell disease (SCD) and are often painful, disabling, and difficult to treat. RGD peptide matrix treatment is a novel therapy designed to provide a topical synthetic extracellular matrix that can act as a temporary substitute for the damaged natural matrix at the ulcer site. In this randomized, placebo-controlled, double-blind, prospective, multicenter investigation, SCD patients with full-thickness leg ulcers were treated with standard therapy plus RGD peptide matrix or saline placebo once weekly for up to 10 weeks. Healing in patients with chronic ulcers (2 months or greater in duration) was significantly accelerated (P = .0085) in RGD peptide matrix recipients compared with the placebo group. In these chronic ulcer cases, the average percent ulcer closure (decrease in ulcer surface area) in the RGD peptide matrix group (54.4% +/- 8.9%) exceeded that in the placebo group (19.0% +/- 24.3%) nearly threefold by study endpoint. Furthermore, RGD peptide matrix was equally effective in promoting healing of long persistent ulcers and ulcers of shorter duration. In contrast, standard therapy plus placebo was significantly less effective (P = .001) in promoting healing for ulcers of progressively greater duration. The results of this study provide preliminary evidence that RGD peptide matrix treatment may significantly accelerate healing of chronic sickle-cell leg ulcers.

Leg ulcers are a chronic manifestation of sickle-cell disease (SCD) and are often painful, disabling, and difficult to treat. RGD peptide matrix treatment is a novel therapy designed to provide a topical synthetic extracellular matrix that can act as a temporary substitute for the damaged natural matrix at the ulcer site. In this randomized, placebo-controlled, double-blind, prospective, multicenter investigation, SCD patients with full-thickness leg ulcers were treated with standard therapy plus RGD peptide matrix or saline placebo once weekly for up to 10 weeks. Healing in patients with chronic ulcers (2 months or greater in duration) was significantly accelerated (P = .0085) in RGD peptide matrix recipients compared with the placebo group. In these chronic ulcer cases, the average percent ulcer closure (decrease in ulcer surface area) in the RGD peptide matrix group (54.4% +/- 8.9%) exceeded that in the placebo group (19.0% +/- 24.3%) nearly threefold by study endpoint. Furthermore, RGD peptide matrix was equally effective in promoting healing of long persistent ulcers and ulcers of shorter duration. In contrast, standard therapy plus placebo was significantly less effective (P = .001) in promoting healing for ulcers of progressively greater duration. The results of this study provide preliminary evidence that RGD peptide matrix treatment may significantly accelerate healing of chronic sickle-cell leg ulcers.

2014 - 2015
Landslide early warning systems are non-structural risk mitigation strategies aiming at dealing with intolerably high probabilities of landslide occurrence by reducing risk through the reduction of the exposed elements. The majority of landslide early warning systems deal with rainfall-induced landslides. The systems can be classified, as a function of the scale of analysis, into: “local” and “regional” systems. Several differences exists among these two different types of warning systems, such as: the actors involved in the process, the monitoring tools, the variables selected to define triggering thresholds, the way the warnings are issued and spread to the public. This work exclusively deals with regional landslide early warning systems (ReLEWSs). These systems are used to assess the probability of occurrence of landslides over appropriately-defined homogeneous alert zones of relevant extension, typically through the prediction and monitoring of meteorological variables, in order to give generalized warnings to administrators and the population. At first, a detailed review of the structure and the functioning of these systems is presented. The information has been gathered mainly from the literature, with the exception of the regional system operating in Campania region, Italy, the municipal system of Rio de Janeiro, Brazil, and the national Norwegian landslide early warning system. The functioning and the structure of the latter two systems have been analyzed in greater depth thanks to research periods spent, respectively, at the GEO-Rio foundation in Rio de Janeiro and at The Norwegian Water Resources and Energy Directorate (NVE) in Oslo. In literature, several authors provided a general description of the structure of a landslide early warning system. Starting from the analysis of these contributions, an original scheme and the main components of such systems for rainfall-induced landslides forecast is proposed. The scheme is based on a clear distinction among the following components: correlation laws, decisional algorithm and warning management. Subsequently, the functioning of the reviewed ReLEWSs has been described according to these components, with a special attention on how the performance of the various warning models was assessed. It is straightforward that a periodical assessment of the technical performance of a landslide early warning system, in terms of evaluation of the warning issued in relation to the landslides occurred, is a required task in order to continuously keep the system reliable. Nevertheless, no standard requirements exist for assessing the performance of regional warning models (ReWaMs) and, typically, this is evaluated by computing the joint frequency distribution of landslides and warnings, both considered as dichotomous variables. Herein, an original methodology to assess the performance of ReWaMs, called the “Event, Duration Matrix, Performance” (EDuMaP) method, is proposed. The performance is evaluated taking into account: the possible occurrence of multiple landslides in the warning zone; the duration of the warnings in relation to the time of occurrence of the landslides; the warning level issued in relation to the landslide spatial density in the warning zone; the relative importance system managers attribute to different types of errors. The applicability of EDuMaP method is tested considering three different ReLEWSs: the municipal early warning system operating in Rio de Janeiro (Brazil); the Norwegian landslide early warning system; the landslide early warning system for hydro-geological risk management of the Campania region, Italy. The main differences among these systems are discussed in great detail, mainly dealing with the functioning and the databases available for the three case studies. The LEWS operational in Rio de Janeiro is employed to issue a certain level of warning in four warning zones in which the municipality is divided. The warnings can be issued at any time during the day if the monitored rainfall exceeds pre-identified thresholds. The Norwegian landslide early warning system is employed to issue daily warnings adopting variable warning zones. In the LEWS of the Campania region each municipality has a reference rain gauge for which three different rainfall threshold are specified for the activation of 3 warning levels. The EDuMaP method was successfully employed to assess the performance for all these case studies, thus underlying the wide applicability of the method, which can be easily adopted to evaluate the performance of any regional landslide early warning systems for which landslides and warnings data are available. For the three case studies, sensitivity analyses are also conducted by varying some of the input parameters of the EDuMaP method. The results of these analyses indicate that the input parameters most affecting the performance of the warning models are: i) the landslide density criterion used to differentiate among the classes of landslide events; ii) the database on landslides considered in the simulations; iii) the time set xvii as the minimum time interval between landslide events; iv) the area of analysis; v) the time frame of the analysis. In conclusion, the analyses prove the applicability of the EDuMaP method in evaluating the performance of real case studies related to ReLWaMs characterized by different decisional algorithms, components and input parameters. The method can also be used as an effective tool to calibrate a warning model by back-analysing landslide and warning data in test area with the aim of defining the set of warning criteria which maximises the model performance. [edited by author]
XIV n.s.

Thesis (M.S.M.E.)--University of Delaware, 2006.
Principal faculty advisors: Suresh G. Advani, Dept. of Mechanical Engineering; and Shridhar Yarlagadda, Shridhar Yarlagadda, Dept. of Electrical and Computer Engineering. Includes bibliographical references.

L’analyse modale a pour objectif d’identifier les modes de vibration d’une structure. Cette discipline peut nécessiter la réalisation d’essais spécifiques sur le système lorsqu’il se trouve en conditions de fonctionnement opérationnel.Pour certaines applications industrielles, ces essais ont une durée et un coût importants. Les acteurs industriels concernés souhaitent donc obtenir de bons résultats tout en essayant de réduire au maximum la durée des essais réalisés. Afin de répondre à ce besoin, l’objectif de ces travaux est de proposer des méthodes d’identification de systèmes linéaires invariants dans le temps qui soient adaptées au traitement d’essais de courte durée en conditions opérationnelles.Premièrement, une approche fondée sur l’identification dans le domaine fréquentiel de fractions matricielles par des méthodes itératives est étudiée. Cette étude permet la formulation d’un algorithme combinant une variable instrumentale itérative et la méthode de Gauss-Newton. Cet algorithme est fondé sur un nouveau paramétrage des fractions matricielles et tient compte de l’état du système aux instants limites considérés. Deuxièmement, un algorithme fondé sur une approche des sous-espaces est proposé. Celui-ci identifie un système sous forme d’état d’après les fonctions de covariance des mesures temporelles d’entrée-sortie. Cet algorithme inclut des pondérations fréquentielles qui tiennent compte de l’état du système aux instants limites considérés. Les deux algorithmes développés sont finalement appliqués à un cas de simulation représentatif des conditions d’essai en vol de flottement d’un avion civil et à des données provenant d’un essai réalisé sur un avion de combat
Modal analysis aims at identifying the vibrational modes of a structure. Estimating these structural modes often requires specific identification tests on the system operating in normal conditions. For some industrial applications, such tests can imply an important time and financial cost. As a consequence, the concerned industrial companies try to get as good result as possible while they also try to reduce as much as possible the duration of a test campaign. This PhD thesis aims at providing linear time invariant system identification methods able to give accurate modal parameter estimations from short duration tests performed in operational conditions.First, an iterative approach based on the identification of matrix fraction descriptions in the frequency domain is studied. This study leads to the formulation of an algorithm combining the use of an iterative instrumental variable method and the use of the Gauss-Newton method. This algorithm is based on a new parametrization of matrix fraction descriptions and takes into account the initial and final state of the system. Second, a subspace-based algorithm is proposed. This one includes frequency weighting matrices which are calculated by considering a frequency band selection and also the initial and final state of the system. Both developed algorithms are finally applied to a simulation case representative of flight flutter-tests conditions of a civil aircraft and to the real data of a flutter test performed on a military aircraft

Die verkehrliche Kapazitätsplanung ist für ÖPNV-Unternehmen ein wichtiger Geschäftsprozess. Die Planungsergebnisse entscheiden maßgeblich über den Einsatz kostenträchtiger Ressourcen und über den Erfolg der ÖPNV-Dienstleistung am Verkehrsmarkt. Trotz dieser Bedeutung beschränkt sich die Planung bisher noch weitgehend auf die Umsetzung von Aufgabenträgervorgaben und vernachlässigt ergänzende Anforderungen der Kunden und Unternehmen. Die vorliegende Arbeit ermittelt die Anforderungen aller relevanten Anspruchsgruppen und benennt Umsetzungsdefizite der heutigen Planungspraxis. Diese Defizite bilden die Grundlage für die Entwicklung einer neuen, anforderungsorientierten Planungsmethodik. Für diese Methodik wird die Qualität des Platzangebotes aus der Perspektive der Kunden definiert und ermittelt. Aus Kundensicht stellt dabei eine uneingeschränkte Sitzplatzverfügbarkeit das höchste Qualitätsniveau dar, während die zulässige Mindestqualität von der kundenseitigen Akzeptanzgrenze für Qualitätsverluste durch Sitzplatzmangel bestimmt wird. Unter Anwendung anerkannter Regeln der Risikobewertung werden zur Bestimmung dieser Qualitätsverluste die Risikoparameter ‚Stehdichte‘, ‚Stehdauer‘ und ‚Stehplatzwahrscheinlichkeit‘ für sämtliche Linienabschnitte und alle Kundenfahrten einer Fahrplanfahrt ermittelt. Dies geschieht auf der Grundlage realisierter Fahrten in Form von haltestellenbasierten Quelle/Ziel-Matrizen. Dem dynamischen Charakter der Risikoparameter im Fahrtverlauf folgend zeigen die Rechenergebnisse stark variierende Qualitätsverluste und liefern so ein transparentes Bild der von den Kunden erlebten Platzqualität. Damit ermöglichen sie die Ermittlung spezifischer Qualitätsniveaus für jede Quelle/Ziel-Gruppe der Matrix und, sofern im elektronischen Fahrgeldmanagementsystem eine Zuordnung von Fahrten zu Kunden erfolgt, auch für unterschiedliche Marktsegmente. Aus den detaillierten Ergebnissen lassen sich zielgerichtete Angebotsmaßnahmen ableiten, deren Realisierung eine bessere Erfüllung der Anforderungen der relevanten Anspruchsgruppen verspricht und Ansätze für ein stärker marktorientiertes Vorgehen bei der Angebotsgestaltung liefert.:Abbildungsverzeichnis VI Verzeichnis der Abkürzungen und Glossar XI Verzeichnis der Formelzeichen und Symbole XIII 1. Einleitung, Zielsetzung und Aufbau der Arbeit 1 2. Status Quo der verkehrlichen Kapazitätsplanung im ÖPNV 5 2.1. Verkehrliche und betriebliche Kapazitätsplanung 5 2.2. Ziele der verkehrlichen Kapazitätsplanung 7 2.3. Ermittlung der Platznachfrage 7 2.3.1. Manuelle Zählungen 8 2.3.2. Automatische Zählungen 9 2.3.3. Auswertung von Vertriebsdaten 9 2.3.4. Fahrgastbefragungen 10 2.3.5. Sonstige Erhebungsmethoden 10 2.4. Ergebnisse der Nachfrageerhebung 10 2.4.1. Verteilung und Schwankungen der Platznachfrage im Netz 10 2.4.2. Stochastische Nachfrageschwankungen 14 2.5. Einfluss der Erhebungsmethoden auf die Durchführung des Planungsprozesses 16 2.6. Ermittlung des Platzangebotes 17 2.6.1. Platzangebotes eines Fahrzeugs 18 2.6.2. Sitzplätze eines Fahrzeugs 18 2.6.3. Stehplätze eines Fahrzeugs 19 2.6.3.1. Ermittlung der Stehplatzfläche eines Fahrzeugs 19 2.6.3.2. Ermittlung der zulässigen Stehdichte im Fahrzeug 19 2.6.4. Sitzplatzanteil eines Fahrzeugs 21 2.6.5. Platzangebot eines Zeitintervalls 23 2.6.6. Vergleich von Platzangebot und Platznachfrage für ein Zeitintervall 24 2.7. Berücksichtigung von Schwankungen der Nachfrage 25 2.8. Begrenzung der Stehdauer der Fahrgäste 28 2.9. Prüfung der Ergebnisse und Anpassung des Platzangebotes 29 2.10. Auswirkung qualitätsbezogener Festlegungen auf das Planungsergebnis 30 2.11. Praxis der verkehrlichen Kapazitätsplanung in Verkehrsunternehmen 34 3. Anforderungen an die verkehrliche Kapazitätsplanung im ÖPNV 39 3.1. Bestimmung der Anspruchsgruppen 39 3.2. Struktur des Planungsprozesses 40 3.3. Anforderungen der Kunden 45 3.3.1. Anforderungen aus der Wahrnehmung von Dienstleistungsqualität 45 3.3.1.1. Anforderungen aus der Diskonfirmationstheorie 46 3.3.1.2. Anforderungen aus der Bildung von Erwartungen 47 3.3.1.3. Anforderungen aus der Wahrnehmung der Leistung 50 3.3.1.4. Anforderungen aus der Einteilung in Zufriedenheitsfaktoren 51 3.3.1.5. Anforderungen aus Einflüssen auf die Kundenzufriedenheit 53 3.3.1.5.1. Assimilations-Kontrast-Theorie 54 3.3.1.5.2. Attributionstheorie 54 3.3.1.5.3. Gerechtigkeitstheorie 55 3.3.1.5.4. Theorie des wahrgenommenen Risikos 56 3.3.1.5.5. Sitzplatz- und Stehflächenmangel als funktionales Risiko 58 3.3.2. Anforderungen der Kunden aus Kundenbefragungen 63 3.3.2.1. Befragungen zur Bevorzugung von Sitzplätzen 64 3.3.2.2. Untersuchungen zur Akzeptanz von Stehdichte 69 3.3.2.3. Untersuchungen zur Akzeptanz von Stehdauer 73 3.3.2.4. Untersuchungen zum Zusammenhang zwischen Stehdichte und Stehdauer 79 3.4. Anforderungen des Unternehmens 82 3.4.1. Anforderungen aus dem Leistungsaustausch am Markt 83 3.4.2. Anforderungen aus den Besonderheiten von Dienstleistungen 88 3.4.2.1. Anforderungen aus der Immaterialität/Intangibilität von Dienstleistungen 89 3.4.2.2. Anforderungen aus der Nichtlagerbarkeit/Nichttransportfähigkeit von Dienstleistungen 90 3.4.2.3. Anforderungen aus der Integration des externen Faktors von Dienstleistungen 90 3.4.2.4. Anforderungen aus der Heterogenität/Individualität von Dienstleistungen 92 3.4.2.5. Zusammenfassung der Anforderungen aus den Besonderheiten von Dienstleistungen 92 3.4.3. Anforderungen aus den Unternehmenszielen 93 3.4.3.1. Anforderungen aus den Marketingstrategien des Unternehmens 96 3.4.3.1.1. Anforderungen aus der Marktfeldstrategie 98 3.4.3.1.2. Anforderungen aus der Marktsegmentierungsstrategie 99 3.4.3.1.3. Anforderungen aus der auf die Abnehmer gerichteten Strategie 103 3.4.4. Anforderungen aus den Modellen der Dienstleistungsqualität 105 3.4.4.1. Anforderungen aus dem GAP-Modell 107 3.4.4.2. Anforderungen aus dem Dienstleistungsqualitätsmodell von Grönroos 110 3.4.4.3. Anforderungen aus dem Dienstleistungsqualitätsmodell von Meyer/Mattmüller 111 3.4.4.4. Anforderungen aus dem Dynamischen Prozessmodell von Boulding/Kalra/Staelin/Zeithaml 112 3.4.4.5. Anforderungen aus dem Beziehungs-Qualitätsmodell von Liljander/Strandvik 113 3.4.4.6. Anforderungen aus dem Qualitativen Zufriedenheitsmodell von Stauss/Neuhaus 115 3.4.5. Anforderungen aus dem operativen Qualitätsmanagement 115 3.4.5.1. Anforderungen aus der Qualitätsplanung 116 3.4.5.2. Anforderungen aus der Qualitätslenkung 117 3.4.5.3. Anforderungen aus der Qualitätsprüfung 118 3.4.5.4. Anforderungen der DIN EN 13816 2002 zur Messung der Dienstleistungsqualität 122 3.4.5.5. Anforderungen aus der Qualitätsmanagementdarlegung 126 3.4.6. Anforderungen aus dem Prozessmanagement 127 3.4.7. Anforderungen an die Erbringung von Kompatibilitätsnachweisen 129 3.5. Anforderungen des Aufgabenträgers 129 3.6. Defizite bei der Erfüllung von Anforderungen durch den Status quo der verkehrlichen Kapazitätsplanung 132 4. Differenzierungsmodell für eine anforderungsorientierte verkehrliche Kapazitätsplanung im ÖPNV 138 4.1. Entwicklungslinien einer anforderungsorientierten Kapazitätsplanung 138 4.2. Entwicklungsschritte des Differenzierungsmodells 140 4.2.1. Stärkung der Nachfrageorientierung 140 4.2.2. Stärkung der Qualitätsorientierung 141 4.2.3. Stärkung der Marktorientierung 143 4.2.4. Stärkung der Kostenorientierung 144 4.3. Methodische Verbesserung der Prozesselemente 145 4.3.1. Arbeitsgrundlagen des Planungsprozesses 146 4.3.2. Prozesselement Planungsvorgaben 146 4.3.3. Prozesselement Nachfrage 146 4.3.4. Prozesselement Angebot 148 4.3.5. Prozesselement Messverfahren 148 4.3.5.1. Definition der zu messenden Platzqualität 150 4.3.5.2. Erläuterungen zur Messung der Platzqualität 152 4.3.5.3. Messung der Risikoparameter für Platzqualität 155 4.3.5.4. Ermittlung der Qualitätsverluste und der Platzqualität 158 4.3.5.5. Variation des Qualitätsziels im Hinblick auf Marktsegmente 162 4.3.6. Prozesselement Ermittlung der Planungsergebnisse 165 4.3.6.1. Ermittlung qualitätsbezogener Kennzahlen 165 4.3.6.2. Ermittlung von Kennzahlen zu Ressourceneinsatz, Betriebsleistung und Kosten 166 4.3.7. Prozesselement Prüfung 166 4.3.7.1. Prüfung der Konformität mit den Unternehmenszielen 167 4.3.7.2. Prüfung der Konformität mit Anforderungen des Aufgabenträgers 167 4.3.8. Prozesselement Veränderung 169 5. Anwendung des Differenzierungsmodells 171 5.1. Gestaltung des Anwendungsbeispiels 171 5.1.1. Festlegungen zur Infrastruktur 171 5.1.2. Festlegungen zum Fahrbetrieb 172 5.1.3. Festlegungen zum Platzangebot 173 5.1.4. Festlegungen zur Platznachfrage 173 5.1.5 Festlegungen zur Platzqualität 174 5.2. Ergebnisse der anwendungsorientierten Planung 175 5.2.1. Standardergebnisse 175 5.2.2. Relevante Einflüsse 182 5.2.2.1. Bemessungsnachfrage 182 5.2.2.2. Platzangebot 183 5.2.2.3. Taktverdichtung 184 5.2.2.4. Qualitätsziel 186 5.2.2.5. Sitzplatzanteil des Fahrzeugs 187 5.2.2.6. Beförderungsgeschwindigkeit 187 5.2.2.7. Fahrgastwechsel 188 5.2.3. Anforderungsorientierung 189 5.2.3.1. Verbesserung der Nachfrageorientierung 190 5.2.3.2. Stärkung der Qualitätsorientierung 190 5.2.3.3. Implementierung der Marktorientierung 191 5.2.3.4. Stärkung der Kostenorientierung 192 6. Fazit und Ausblick 195 Quellenverzeichnis 199 Verzeichnis der Anhänge 208 Anhang A: Befragung größerer Verkehrsunternehmen zur Praxis der verkehrliche Kapazitätsplanung im schienengebundenen ÖPNV 208 Anhang B: Befragung der Fahrgäste zum Sitzplatzwunsch und zur Fahrtdauer 211 Anhang C: Befragung der U-Bahn-Fahrgäste zum Sitzplatzbedarf im Zusammenhang mit der Beschäftigung während der Fahrt sowie mit dem Alter und dem Geschlecht 214 Anhang D: Befragung der U-Bahn-Fahrgäste zur akzeptierten Stehdauer im Zusammenhang mit der Stehplatzdichte sowie mit dem Alter und dem Geschlecht 216 Anhang E: Befragung der U-Bahn-Fahrgäste der Linie U3 zum Sitzplatzwunsch und zur akzeptierten Stehdauer im Zusammenhang mit der während der Befragung vorgefundenen Stehplatzdichte 217
Transport related capacity planning constitutes an important business process for public transport companies. Respective results have a crucial impact on the allocation of costly resources and on public transport services. Despite this significance, planning is mostly limited to implementing standards put forth by authorities thereby neglecting to address complementary customer and corporate needs. The paper determines relevant stakeholder requirements and depicts implementation deficits of current planning methods. Furthermore, these deficiencies allow for laying the foundation to develop a new requirement based planning methodology. Against this backdrop the quality of available space from a customer perspective is defined and derived. Moreover, from the aforementioned perspective the ample provision of available space is brought to focus while bearing a minimal customer based quality threshold - determined by loss of seating capacity - in mind. By applying all renowned standards pertaining to risk assessment relevant parameters such as standing density, - duration and -probability are determined for all customer related trips of a schedule. The aforementioned approach is based on realized trips in relation to an underlying stop-oriented origin-destination-matrix. Following dynamic characteristics of risk parameters en route the calculation results depict a stark variation in outcome as to loss of quality. Hence, a vivid picture attributed to customer`s perceived seating quality emerges. In so far as an electronic fare management system is in place specific quality levels with regard to an underlying origin-destination-matrix based on assigned customer trips can be derived while also taking various market segments into consideration. Emphasis is laid upon a market-oriented approach bringing to focus enhanced services. Moreover, detailed results allow for deriving concise measures, which in turn improve compliance pertaining to relevant stakeholder requirements.:Abbildungsverzeichnis VI Verzeichnis der Abkürzungen und Glossar XI Verzeichnis der Formelzeichen und Symbole XIII 1. Einleitung, Zielsetzung und Aufbau der Arbeit 1 2. Status Quo der verkehrlichen Kapazitätsplanung im ÖPNV 5 2.1. Verkehrliche und betriebliche Kapazitätsplanung 5 2.2. Ziele der verkehrlichen Kapazitätsplanung 7 2.3. Ermittlung der Platznachfrage 7 2.3.1. Manuelle Zählungen 8 2.3.2. Automatische Zählungen 9 2.3.3. Auswertung von Vertriebsdaten 9 2.3.4. Fahrgastbefragungen 10 2.3.5. Sonstige Erhebungsmethoden 10 2.4. Ergebnisse der Nachfrageerhebung 10 2.4.1. Verteilung und Schwankungen der Platznachfrage im Netz 10 2.4.2. Stochastische Nachfrageschwankungen 14 2.5. Einfluss der Erhebungsmethoden auf die Durchführung des Planungsprozesses 16 2.6. Ermittlung des Platzangebotes 17 2.6.1. Platzangebotes eines Fahrzeugs 18 2.6.2. Sitzplätze eines Fahrzeugs 18 2.6.3. Stehplätze eines Fahrzeugs 19 2.6.3.1. Ermittlung der Stehplatzfläche eines Fahrzeugs 19 2.6.3.2. Ermittlung der zulässigen Stehdichte im Fahrzeug 19 2.6.4. Sitzplatzanteil eines Fahrzeugs 21 2.6.5. Platzangebot eines Zeitintervalls 23 2.6.6. Vergleich von Platzangebot und Platznachfrage für ein Zeitintervall 24 2.7. Berücksichtigung von Schwankungen der Nachfrage 25 2.8. Begrenzung der Stehdauer der Fahrgäste 28 2.9. Prüfung der Ergebnisse und Anpassung des Platzangebotes 29 2.10. Auswirkung qualitätsbezogener Festlegungen auf das Planungsergebnis 30 2.11. Praxis der verkehrlichen Kapazitätsplanung in Verkehrsunternehmen 34 3. Anforderungen an die verkehrliche Kapazitätsplanung im ÖPNV 39 3.1. Bestimmung der Anspruchsgruppen 39 3.2. Struktur des Planungsprozesses 40 3.3. Anforderungen der Kunden 45 3.3.1. Anforderungen aus der Wahrnehmung von Dienstleistungsqualität 45 3.3.1.1. Anforderungen aus der Diskonfirmationstheorie 46 3.3.1.2. Anforderungen aus der Bildung von Erwartungen 47 3.3.1.3. Anforderungen aus der Wahrnehmung der Leistung 50 3.3.1.4. Anforderungen aus der Einteilung in Zufriedenheitsfaktoren 51 3.3.1.5. Anforderungen aus Einflüssen auf die Kundenzufriedenheit 53 3.3.1.5.1. Assimilations-Kontrast-Theorie 54 3.3.1.5.2. Attributionstheorie 54 3.3.1.5.3. Gerechtigkeitstheorie 55 3.3.1.5.4. Theorie des wahrgenommenen Risikos 56 3.3.1.5.5. Sitzplatz- und Stehflächenmangel als funktionales Risiko 58 3.3.2. Anforderungen der Kunden aus Kundenbefragungen 63 3.3.2.1. Befragungen zur Bevorzugung von Sitzplätzen 64 3.3.2.2. Untersuchungen zur Akzeptanz von Stehdichte 69 3.3.2.3. Untersuchungen zur Akzeptanz von Stehdauer 73 3.3.2.4. Untersuchungen zum Zusammenhang zwischen Stehdichte und Stehdauer 79 3.4. Anforderungen des Unternehmens 82 3.4.1. Anforderungen aus dem Leistungsaustausch am Markt 83 3.4.2. Anforderungen aus den Besonderheiten von Dienstleistungen 88 3.4.2.1. Anforderungen aus der Immaterialität/Intangibilität von Dienstleistungen 89 3.4.2.2. Anforderungen aus der Nichtlagerbarkeit/Nichttransportfähigkeit von Dienstleistungen 90 3.4.2.3. Anforderungen aus der Integration des externen Faktors von Dienstleistungen 90 3.4.2.4. Anforderungen aus der Heterogenität/Individualität von Dienstleistungen 92 3.4.2.5. Zusammenfassung der Anforderungen aus den Besonderheiten von Dienstleistungen 92 3.4.3. Anforderungen aus den Unternehmenszielen 93 3.4.3.1. Anforderungen aus den Marketingstrategien des Unternehmens 96 3.4.3.1.1. Anforderungen aus der Marktfeldstrategie 98 3.4.3.1.2. Anforderungen aus der Marktsegmentierungsstrategie 99 3.4.3.1.3. Anforderungen aus der auf die Abnehmer gerichteten Strategie 103 3.4.4. Anforderungen aus den Modellen der Dienstleistungsqualität 105 3.4.4.1. Anforderungen aus dem GAP-Modell 107 3.4.4.2. Anforderungen aus dem Dienstleistungsqualitätsmodell von Grönroos 110 3.4.4.3. Anforderungen aus dem Dienstleistungsqualitätsmodell von Meyer/Mattmüller 111 3.4.4.4. Anforderungen aus dem Dynamischen Prozessmodell von Boulding/Kalra/Staelin/Zeithaml 112 3.4.4.5. Anforderungen aus dem Beziehungs-Qualitätsmodell von Liljander/Strandvik 113 3.4.4.6. Anforderungen aus dem Qualitativen Zufriedenheitsmodell von Stauss/Neuhaus 115 3.4.5. Anforderungen aus dem operativen Qualitätsmanagement 115 3.4.5.1. Anforderungen aus der Qualitätsplanung 116 3.4.5.2. Anforderungen aus der Qualitätslenkung 117 3.4.5.3. Anforderungen aus der Qualitätsprüfung 118 3.4.5.4. Anforderungen der DIN EN 13816 2002 zur Messung der Dienstleistungsqualität 122 3.4.5.5. Anforderungen aus der Qualitätsmanagementdarlegung 126 3.4.6. Anforderungen aus dem Prozessmanagement 127 3.4.7. Anforderungen an die Erbringung von Kompatibilitätsnachweisen 129 3.5. Anforderungen des Aufgabenträgers 129 3.6. Defizite bei der Erfüllung von Anforderungen durch den Status quo der verkehrlichen Kapazitätsplanung 132 4. Differenzierungsmodell für eine anforderungsorientierte verkehrliche Kapazitätsplanung im ÖPNV 138 4.1. Entwicklungslinien einer anforderungsorientierten Kapazitätsplanung 138 4.2. Entwicklungsschritte des Differenzierungsmodells 140 4.2.1. Stärkung der Nachfrageorientierung 140 4.2.2. Stärkung der Qualitätsorientierung 141 4.2.3. Stärkung der Marktorientierung 143 4.2.4. Stärkung der Kostenorientierung 144 4.3. Methodische Verbesserung der Prozesselemente 145 4.3.1. Arbeitsgrundlagen des Planungsprozesses 146 4.3.2. Prozesselement Planungsvorgaben 146 4.3.3. Prozesselement Nachfrage 146 4.3.4. Prozesselement Angebot 148 4.3.5. Prozesselement Messverfahren 148 4.3.5.1. Definition der zu messenden Platzqualität 150 4.3.5.2. Erläuterungen zur Messung der Platzqualität 152 4.3.5.3. Messung der Risikoparameter für Platzqualität 155 4.3.5.4. Ermittlung der Qualitätsverluste und der Platzqualität 158 4.3.5.5. Variation des Qualitätsziels im Hinblick auf Marktsegmente 162 4.3.6. Prozesselement Ermittlung der Planungsergebnisse 165 4.3.6.1. Ermittlung qualitätsbezogener Kennzahlen 165 4.3.6.2. Ermittlung von Kennzahlen zu Ressourceneinsatz, Betriebsleistung und Kosten 166 4.3.7. Prozesselement Prüfung 166 4.3.7.1. Prüfung der Konformität mit den Unternehmenszielen 167 4.3.7.2. Prüfung der Konformität mit Anforderungen des Aufgabenträgers 167 4.3.8. Prozesselement Veränderung 169 5. Anwendung des Differenzierungsmodells 171 5.1. Gestaltung des Anwendungsbeispiels 171 5.1.1. Festlegungen zur Infrastruktur 171 5.1.2. Festlegungen zum Fahrbetrieb 172 5.1.3. Festlegungen zum Platzangebot 173 5.1.4. Festlegungen zur Platznachfrage 173 5.1.5 Festlegungen zur Platzqualität 174 5.2. Ergebnisse der anwendungsorientierten Planung 175 5.2.1. Standardergebnisse 175 5.2.2. Relevante Einflüsse 182 5.2.2.1. Bemessungsnachfrage 182 5.2.2.2. Platzangebot 183 5.2.2.3. Taktverdichtung 184 5.2.2.4. Qualitätsziel 186 5.2.2.5. Sitzplatzanteil des Fahrzeugs 187 5.2.2.6. Beförderungsgeschwindigkeit 187 5.2.2.7. Fahrgastwechsel 188 5.2.3. Anforderungsorientierung 189 5.2.3.1. Verbesserung der Nachfrageorientierung 190 5.2.3.2. Stärkung der Qualitätsorientierung 190 5.2.3.3. Implementierung der Marktorientierung 191 5.2.3.4. Stärkung der Kostenorientierung 192 6. Fazit und Ausblick 195 Quellenverzeichnis 199 Verzeichnis der Anhänge 208 Anhang A: Befragung größerer Verkehrsunternehmen zur Praxis der verkehrliche Kapazitätsplanung im schienengebundenen ÖPNV 208 Anhang B: Befragung der Fahrgäste zum Sitzplatzwunsch und zur Fahrtdauer 211 Anhang C: Befragung der U-Bahn-Fahrgäste zum Sitzplatzbedarf im Zusammenhang mit der Beschäftigung während der Fahrt sowie mit dem Alter und dem Geschlecht 214 Anhang D: Befragung der U-Bahn-Fahrgäste zur akzeptierten Stehdauer im Zusammenhang mit der Stehplatzdichte sowie mit dem Alter und dem Geschlecht 216 Anhang E: Befragung der U-Bahn-Fahrgäste der Linie U3 zum Sitzplatzwunsch und zur akzeptierten Stehdauer im Zusammenhang mit der während der Befragung vorgefundenen Stehplatzdichte 217

Ce mémoire s’intéresse aux modèles de Markov à variables latentes, une famille de modèles dans laquelle une chaîne de Markov latente régit le comportement d’un processus stochastique observable à travers duquel transparaît une version bruitée de la chaîne cachée. Pouvant être vus comme une généralisation naturelle des modèles de mélange, ces processus stochastiques bivariés ont entre autres démontré leur faculté à capter les dynamiques variables de maintes séries chronologiques et, plus spécifiquement en finance, à reproduire la plupart des faits stylisés des rendements financiers. Nous nous intéressons en particulier aux chaînes de Markov à temps discret et à espace d’états fini, avec l’objectif d’étudier l’apport de leurs reformulations hiérarchiques et de la relaxation de l’hypothèse d’homogénéité de la matrice de transition à la qualité de l’ajustement aux données et des prévisions, ainsi qu’à la reproduction des faits stylisés. Nous présentons à cet effet deux structures hiérarchiques, la première permettant une nouvelle interprétation des relations entre les états de la chaîne, et la seconde permettant de surcroît une plus grande parcimonie dans la paramétrisation de la matrice de transition. Nous nous intéressons de plus à trois extensions non-homogènes, dont deux dépendent de variables observables et une dépend d’une autre variable latente. Nous analysons pour ces modèles la qualité de l’ajustement aux données et des prévisions sur la série des log-rendements du S&P 500 et du taux de change Canada-États-Unis (CADUSD). Nous illustrons de plus la capacité des modèles à reproduire les faits stylisés, et présentons une interprétation des paramètres estimés pour les modèles hiérarchiques et non-homogènes. Les résultats obtenus semblent en général confirmer l’apport potentiel de structures hiérarchiques et des modèles non-homogènes. Ces résultats semblent en particulier suggérer que l’incorporation de dynamiques non-homogènes aux modèles hiérarchiques permette de reproduire plus fidèlement les faits stylisés—même la lente décroissance de l’autocorrélation des rendements centrés en valeur absolue et au carré—et d’améliorer la qualité des prévisions obtenues, tout en conservant la possibilité d’interpréter les paramètres estimés.
This master’s thesis is centered on the Hidden Markov Models, a family of models in which an unobserved Markov chain dictactes the behaviour of an observable stochastic process through which a noisy version of the latent chain is observed. These bivariate stochastic processes that can be seen as a natural generalization of mixture models have shown their ability to capture the varying dynamics of many time series and, more specifically in finance, to reproduce the stylized facts of financial returns. In particular, we are interested in discrete-time Markov chains with finite state spaces, with the objective of studying the contribution of their hierarchical formulations and the relaxation of the homogeneity hypothesis for the transition matrix to the quality of the fit and predictions, as well as the capacity to reproduce the stylized facts. We therefore present two hierarchical structures, the first allowing for new interpretations of the relationships between states of the chain, and the second allowing for a more parsimonious parameterization of the transition matrix. We also present three non-homogeneous models, two of which have transition probabilities dependent on observed explanatory variables, and the third in which the probabilities depend on another latent variable. We first analyze the goodness of fit and the predictive power of our models on the series of log returns of the S&P 500 and the exchange rate between canadian and american currencies (CADUSD). We also illustrate their capacity to reproduce the stylized facts, and present interpretations of the estimated parameters for the hierarchical and non-homogeneous models. In general, our results seem to confirm the contribution of hierarchical and non-homogeneous models to these measures of performance. In particular, these results seem to suggest that the incorporation of non-homogeneous dynamics to a hierarchical structure may allow for a more faithful reproduction of the stylized facts—even the slow decay of the autocorrelation functions of squared and absolute returns—and better predictive power, while still allowing for the interpretation of the estimated parameters.

According to current industrial and societal demands, product manufacturing is now highly competitive. The current research is primarily focused on the creation of functionally graded materials that are essential for automotive cylinders and their internal components. Since aluminum plays a significant role in automobile components, layerwise deposition of the matrix and reinforcements is used. Aluminum alloy (Al 356) was investigated in weight proportions of 100, 95, and 90%, while the reinforcement varied from 0 to 7.5%. The particulate reinforcements were chosen to be silicon carbide (SiC) and nickel (Ni). Zinc stearate is used as lubricating agent to enhance the free-flow compaction process and to avoid the wastage in synthesis. The compressed specimens were examined for various mechanical and microstructural characterization. An ultimate compressive strength of 328 MPa and 68 BHN was achieved at 85% Al, 5% SiC, and 7.5% Ni, as per research criterion. Scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), and X-ray diffraction analysis (XRD) images of the inclusions and matrix are compatible and compact due to the excellent bonding. The process variables were adjusted using Taguchi optimization, which shows that the sintering duration and compaction pressure are crucial for the validation of manufacturing and characterization.

Abstract Chapter 5 builds upon the classic anthropological discussion on dead and their names. It shows how proper names are lost for a short duration at death and also how the corpse occupies different generic names as it moves from one threshold to another. The sociological matrix of funerary work, municipal handling of the dead at the electric crematorium, and other associated concerns find their way into these descriptions. Anthropologists have rightly approached the meaning of Hindu death as a closure by following the communitarian route of the funeral, from the cremation ghat to home. While this chapter does the same, it also maps the converse. By staying at the ghat after the respective funeral travellers have left the author records their dead as social relations of remainders. Tracking these remainders, the author moves to a conversation of pyres. This conversation brings up the context of cremation-related environmental anguish in a comparative perspective by drawing from his ethnography of recirculation of heat in a Danish crematorium. The chapter’s end alludes to an incommensurate ethical parallel between the various names of the city and the registers of pravah and parvah to signify the funeral act in Banaras as a coming together of contemplation, mourning, and care in the flow of life.

Previous chapters present the characteristics of drug movement through the body. Diffusion is an essential mode of transport at the microscopic scale; concentration gradients drive a substantial fraction of the molecular movements within cells and the extracellular space. The confinement and regulated passage of molecules within compartments of a tissue or cell is also essential for function; membranes confine molecules to spatial locations and regulate transport between these isolated spaces (Chapter 5). Membranes frequently are the major obstacles to the entry or distribution of therapeutic compounds (Chapter 7). Therefore, much of the effort in drug design and drug delivery is devoted to overcoming these diffusional or membrane barriers. This chapter describes strategies for manipulating agents in order to increase their biological activity. The sections orbit a central assumption: i.e., agents can be modified to make analogous agents (analogs), which are chemically distinct from the original compound, but produce a similar biological effect. Nature uses a similar strategy, called “biotransformation” to assure elimination of many toxic compounds and drugs. Substantial chemical modification is often needed in order to impact physical properties that influence drug distribution such as stability or solubility; the challenge of drug modification is to identify chemical features that can be changed without sacrificing biological activity. Often, our understanding of the relationship between chemical structure and biological function for an agent is incomplete, making the rational production of analogs difficult. Drug modifications are frequently directed at altering properties that influence the concentration of the compound (i.e., its solubility), the duration of action (which is usually related to its stability in tissue), or the ability of drug molecules to move between compartments in tissues (which is often related to its permeability in membranes). A chemical modification can effect multiple properties, so these divisions are frequently not as distinct as the section headings suggest. Many agents are protected from degradation within tissues by binding. Binding provides a mechanism for sequestering an unstable or potent compound within a region of a tissue. Protective binding occurs frequently within the plasma and extracellular matrix (ECM); the complex molecular composition of these tissues provides many potential binding sites.

A new concept of Ceramic Matrix Composite (CMC), mainly based on the use of a self–sealing technology for matrix and the use of a multilayer woven reinforcement, has been developed by Snecma for achieving high performance levels targeted by future jet engines. The driving force for this development has been to increase both lifetime and temperature capability of previous C/SiC and SiC/SiC materials using a monolithic SiC Chemical Vapor Infiltration (CVI) matrix and finishing treatment against oxidation. The first material, which has been developed with this new approach, is CERASEP® A410, using Hi-Nicalon™ fibers from Nippon Carbon. It has been submitted to a comprehensive characterization in order to determine thermo-mechanical properties and to evaluate lifetime duration, using fatigue and creep testing. Further material development is investigating the use of carbon fiber for economical objectives. The combination of such fibers with the new self-sealing matrix is providing promising results for long duration application at high temperature. Such results are permitted by the very high potential of the new matrix.

An optimization strategy to reduce residual vibration of rest-to-rest maneuvers of overhead cranes is proposed. The proposed technique is based on generating shaped acceleration commands for a simple harmonic oscillator with damping included. Furthermore, the proposed technique solves the problem of discrete signal commands that result from using slow digital to analog convertors on real cranes. A discretized acceleration profile is derived analytically using finite step segments. These segments are integrated into a matrix, which is then coupled with a system response matrix through the system’s equations of motion. The resulting input acceleration matrix is then optimized to satisfy rest-to-rest maneuver conditions. The profile designer can control many parameters such as maneuver duration, discrete time step, hoisting speed, damping ratio, maximum velocity and acceleration. Unlike traditional command shapers, the proposed shaped profiles are independent of the natural period of the system, i.e., the acceleration profile duration is designer selectable. Through several examples, the performance of the proposed controller is validated numerically. Results show that the proposed shaping technique can effectively eliminate residual vibrations in rest-to-rest maneuvers of damped single-degree-of-freedom systems.

Abstract A model for solder behavior based on nonlinear dynamics has been developed by the authors (1990–1992). Supporting this study, data have been collected for near eutectic Pb-Sn solder joints using a ring and plug geometry which has been subjected to isothermal (80°C, 120°C) creep/relaxation loading ranging over a period of time up to 260 hours. Four types of relaxation data were observed: (1) smooth, low rate of unloading, (2) smooth, high rate of unloading, (3) onset of unstable racheting, and (4) onset of unstable, irregular unloading. Types (1) and (2) appear to be related to grain boundary and matrix creep, respectively. These are two creep mechanisms which have been reported in the literature. As far as we are aware, types (3) and (4) have not been previously reported by other investigators in terms related to solder instability. Therefore, our purpose is to document, in some detail, conditions under which unstable behavior has been observed. A detailed discussion is made of variables which control and measure instability including loading, fixture load cell stiffness and material type, and checks of instrumentation accuracy. This paper reports details of the experimental study regarding test specimens, test fixture, instrumentation and calibration, and environmental control. This paper provides a summary of data collection.

Wire-cut Electro Discharge Machining (WEDM) is a special form of conventional EDM process in which electrode is a continuously moving conductive wire. The present study aims at determining parametric influence and optimum process parameters of Wire-EDM using Taguchi’s Technique and Genetic algorithm. The variation of the performance parameters with machining parameters was mathematically modeled by Regression analysis method. The objective functions are Dimensional Accuracy (DA) and Volumetric Material Removal Rate (VMRR). Experiments were designed as per Taguchi’s L16 Orthogonal Array (OA) where in Pulse-on duration, Current, Pulse-off duration, Bed-speed and Flushing rate have been considered as the important input parameters. The matrix experiments were conducted for the material Oil Hardened Non Shrinking Steel (OHNS) having the thickness of 40 mm. The results of the study reveals that among the machining parameters it is preferable to go in for smaller pulse-off duration for achieving over all good performance. Regarding MRR, OHNS is to be eroded with medium pulse-off duration and higher flush rate. Finally, the validation exercise performed with the optimum levels of the process parameters. The results confirm the efficiency of the approach employed for optimization of process parameters in this study.

Abstract Aluminum alloys reinforced with B4C particle of average particle size of 10.5 μm and 20.9 μm were exposed to 535°C for various duration. The material degradation was evaluated by both mechanical and acoustic emission monitoring during tensile test. The micromechanisms of fracture changed from particle fracture and debonding, for as received specimens, to particle/matrix debonding after exposure to high temperature. The cumulative acoustic emission (AE) events during post heat exposure reduced with the increase of heal damage on the specimen. A Weibull probability distribution function that incorporates heat damage and relates to the cumulative events is developed. This model could be used to evaluate the extent of heat damage to a composite specimen.

Abstract A significant challenge within the manufacturing of Ceramic Matrix Composites (CMCs) is the creation of the fibre-matrix interphase which enables the damage tolerant behavior of CMCs. Chemical vapour deposition (CVD) has been a highly successful approach for fabricating fibre-matrix interphases; however, CVD requires capital intensive facilities and hazardous precursors. This work examines electrophoretic deposition (EPD) as an alternative route for the production of fibre-matrix interphases. Four multilayered fibre-matrix interphases (SiC/Al2O3, BN/ZrO2, ZrC/85wt%Al2O3-15wt%ZrO2, and SiC/Si3N4/SiC) were produced through multi-staged electrophoretic deposition of ceramic nano-powders upon SiC fibre bundles. A 25-2 factorial design of experiments is utilized to explore the effect of different levels of the following variables: electric field strength, duration, surfactant, solids loading and binder. Following deposition of the fibre-matrix interphase the fibre bundles are thinly coated with a SiC matrix through a reactive melt infiltration technique. The resultant microcomposites are then subjected to tensile loading until failure to determine which coating and deposition combination are the most likely to yield favorable tensile properties. Additional microscopy is performed to determine the uniformity and thickness of the coatings. The results are then examined to evaluate the suitability of electrophoretic deposition as a production technique for fibre-matrix interphase coatings in CMCs.

Various fibrous tissues such as tendons and ligaments functionally adapt to dynamic and static loads. Although a variety of biomechanical studies have been performed so far to determine the mechanism of remodelling in fibrous tissues, it was difficult to obtain detailed information because of complicated constitution of the tissues. Meanwhile we have been developing a stem cell-based self-assembled tissue (scSAT) for tissue engineering, composed of synovial-derived mesenchymal stem cells (MSCs) and their native extracellular matrix. The scSAT used for cartilage repair is called tissue engineered construct (TEC) [1, 2]. Since the scSAT specimen is consisted of stem cells and their native extracellular matrix, it can be a good experimental model of fibrous tissues to determine the process of remodelling. Therefore, the effects of cyclic tensioning and its duration on the mechanical property of the scSAT specimen were investigated in the present study. It was also the purpose of the present study to determine the bio-synthesis condition adequate for improving the mechanical property of the scSAT specimen.