Dissertations / Theses on the topic 'Damage and Loss Assessment'

Quantitative risk assessments are a fundamental part of economic analysis and natural hazard risk management models. It increases the objectivity and the transparency of risk assessments and guides policymakers in making efficient decisions when spending public resources on risk reduction. Managing hazard risks calls for an understanding of the relationships between hazard exposure and vulnerability of humans and assets.   The purpose of this thesis is to identify and estimate causal relationships between hazards, exposure and vulnerability, and to evaluate the applicability of systematically collected data sets to produce reliable and generalizable quantitative information for decision support.   Several causal relationships have been established. For example, the extent of lake flood damage to residential buildings depends on the duration of floods, distance to waterfront, the age of the house and in some cases the water level. Results also show that homeowners private initiative to reduce risk, prior to or during a flood, reduced their probability of suffering building damage with as much as 40 percent. Further, a causal relationship has been established between the number of people exposed to quick clay landslides and landslide fatalities.   Even though several relationships were identified between flood exposure and vulnerability, the effects can only explain small parts of the total variation in damages, especially at object level. The availability of damage data in Sweden is generally low. The most comprehensive damage data sets in Sweden are held by private insurance companies and are not publicly available. Data scarcity is a barrier to quantitative natural hazard risk assessment in Sweden. More efforts should therefore be made to collect data systematically for modelling and validating standardized approaches to quantitative damage estimation.
Natural hazard damages have increased worldwide. Impacts caused by hydrological and meteorological hazards have increased the most. An analysis of insurance payments in Sweden showed that flood damages have been increasing in Sweden as well. With climate change and increasing populations we can expect this trend to continue unless efforts are made to reduce risk and adapt communities to the threats. Economic analysis and quantitative risk assessments of natural hazards are fundamental parts of a risk management process that can support policymakers' decisions on efficient risk reduction. However, in order to develop reliable damage estimation models knowledge is needed of the relationships between hazard exposure and the vulnerability of exposed objects and persons. This thesis has established causal relationships between residential exposure and flood damage on the basis of insurance data. I also found that private damage-reducing actions decreased the probability of damage to buildings with almost 40 percent. Further, a causal relationship has been established between the number of people exposed to quick clay landslides and fatalities. Even though several relationships have been identified between flood exposure and vulnerability, the effects can explain only small parts of the total variation in damages, especially at object level, and more effort is needed to develop quantitative models for risk assessment purposes.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2001.
Includes bibliographical references (leaves 145-149).
Large earthquakes have the potential of causing extensive damage and enormous economic losses. These losses are primarily attributable to the reduction in functionality of various facilities in the affected region and the rebuilding costs, and can be reduced through strategic pre- and post-earthquake decisions. This thesis describes an integrated methodology to estimate losses due to scenario earthquakes, with emphasis on the reduced functionality of the transportation infrastructure. The methodology integrates variables that were previously considered exogenous to the transportation system, through models for reduced industrial production capacity, and damage to lifelines, residential clusters and other structural components in an integrated framework. By modifying input parameters, one can evaluate the effect on the losses of various mitigating actions. The methodology is thus useful for prioritizing retrofitting efforts and in general for developing pre and post- earthquake strategies for lowering economic losses. A case study of a New Madrid scenario earthquake is presented. Future efforts needed to improve the loss estimation capability of this methodology are identified.
by Umang Gupta.
S.M.

[EN] A simplified analytical method ("FAST") for the estimation of large-scale vulnerability of Reinforced Concrete (RC) Moment Resisting Frames with masonry infills is proposed and subsequently tested by using real damage scenario caused by the 2011 Lorca earthquake as a benchmark. FAST is a spectral-based approach that allows predicting the average non-structural Damage State expected for each class of building (defined by number of storeys, age of construction, infills ratio in plan and location) for a given demand level. It accounts for non-uniformity of infills in elevation, i.e. a reduction of infills ratio of the ground floor. FAST is based on: (i) the definition of approximated capacity curves of the infilled building, assuming that the RC frame is designed according to the corresponding seismic code; and on (ii) the assumption of "a priori" deformed shapes in accordance with the attainment of each non-structural damage state at 1st storey, estimated through experimental and numerical correlations. Two versions of FAST are proposed: a "simplified" approach aimed at the evaluation of uniformly infilled frames; and a "generalised" version which can account for any intermediate situation between uniformly infilled frames and pilotis frames (i.e. without infills at 1st storey). Also, some extensions of the method are highlighted. Aimed at testing FAST, the real damage scenario after the earthquake of Lorca (2011) is used as a benchmark, despite its impulsivity and directivity. In order to define the specific input parameters for the case study, information regarding ground motion, post-earthquake damage scenario and also building design practice must be collected. Hence, a detailed review of historical Spanish seismic codes and a critical analysis of current Spanish seismic code NCSE-02 in comparison with current reference performance-based codes such as Eurocode 8 are provided. Special emphasis is placed on provisions which can prevent a proper capacity design and that, in turn, can cause brittle failures or favour the interaction with infills. Also, the prescription of lower behaviour factor for wide-beam frames with respect to deep-beam frames -which is not present in most codes¿ is discussed; outcomes of several case studies suggest that such prescription is obsolete. Finally, FAST is applied to Lorca earthquake and predicted damage scenarios are obtained, considering different assumptions for input values. Results show proper agreement between predicted and real damages. Structural collapses were rarely observed, even though the PGA was three times higher than the typical acceleration of design, so FAST proves that masonry infills provided additional strength to RC frames.
[ES] Se propone un método analítico simplificado ("FAST") para la estimación de la vulnerabilidad a gran escala de edificios porticados de hormigón armado con tabiquería de fábrica, posteriormente testeado mediante la adopción del escenario de daño real correspondiente al terremoto de Lorca de 2011 como patrón de comparación. FAST es un procedimiento espectral que permite predecir el nivel de daño no estructural medio esperado para cada clase de edificio (definido por su número de plantas, año de construcción, densidad de tabiquería en planta y localización geográfica), considerando un nivel de demanda dado. El método tiene en cuenta la irregularidad de la tabiquería en alzado, es decir, la posible reducción relativa de tabiquería en planta baja. FAST se basa en: (i) la definición de curvas de capacidad aproximadas para los edificios tabicados, asumiendo que la estructura de HA se ha proyectado según la norma sísmica correspondiente en cada caso; y en (ii) la asunción de deformadas "apriorísticas" coherentes con cada grado de daño (suponiendo que éste se alcanza siempre en planta baja), estimadas a través de correlaciones experimentales y numéricas. Se proponen dos versiones de FAST: una "simplificada" para la evaluación de edificios uniformemente tabicados en altura, y otra "generalizada", que es capaz de tener en cuenta cualquier situación intermedia entre el prototipo uniformemente tabicado y el de planta baja diáfana. Además, se proponen ciertas extensiones al método. A fin de validar FAST, se elige el escenario de daño real correspondiente al terremoto de Lorca (2011) como patrón de comparación, a pesar de su impulsividad y directividad. Para definir los parámetros de input correspondientes al caso de estudio, es necesario recopilar previamente la información concerniente a la señal sísmica, el escenario de daño y las características del parque construido. Por tanto, se lleva a cabo una revisión exhaustiva de las normas sísmicas históricas en España y un análisis crítico de la norma sísmica española actual NCSE-02 en comparación con otras normas actuales de referencia basadas en el desempeño, como el Eurocódigo 8, haciendo énfasis en las provisiones que no garantizan el diseño por capacidad y que por tanto pueden provocar mecanismos frágiles o favorecer la excesiva influencia de la tabiquería. Además, se discute sobre la restricción del coeficiente de ductilidad en estructuras de vigas planas, cuestión que no se refleja en otras normas. Los resultados obtenidos mediante análisis de casos de estudio muestran que dicha prescripción resulta obsoleta para normas actuales. Finalmente, FAST se aplica al caso del terremoto de Lorca, obteniéndose predicciones de daño medio para diferentes asunciones. Los resultados muestran una coincidencia aceptable entre la predicción y los daños reales. FAST confirma que la causa principal de la práctica ausencia de colapsos (ante un terremoto con PGA triple que la típica de proyecto) hay que buscarla en la contribución estructural de la tabiquería de fábrica.
[CAT] Es proposa un mètode analític simplificat ("FAST") per a l'estimació de la vulnerabilitat a gran escala d'edificis porticats de formigó armat amb envans de fàbrica. Posteriorment, el mètode ha estat testejat mitjançant l'adopció de l'escenari de dany real corresponent al terratrèmol de Lorca de 2011 com a patró de comparació. FAST és un procediment espectral que permet predir el nivell de dany no estructural mitjà esperat per a cada classe d'edifici (definit pel seu nombre de plantes, any de construcció, densitat d'envans en planta i localització geogràfica), considerant un determinat nivell de demanda. El mètode té en compte la irregularitat de la distribució de envans al llarg de les diferents plantes del edifici. Es a dir, es pot tenir en compte que, freqüentment, hi ha una menor quantitat de d'envans a la planta baixa. FAST es fonamenta en: (i) la definició de corbes de capacitat aproximades que tenen en compte no sols la estructura del edifici sinó també els envans i assumint que l'estructura de HA s'ha projectat segons la norma sísmica corresponent en cada cas; (ii) l'assumpció de deformades "apriorístiques" coherents amb cada grau de dany (suposant que aquest es dona sempre a la planta baixa) que han estat estimades a través de correlacions experimentals i numèriques. Es proposen dues versions de FAST: una "simplificada" per a l'avaluació d'edificis amb envans uniformement repartits per totes les plantes, i una altra "generalitzada", que és capaç de tenir en compte qualsevol situació intermèdia entre el prototip uniformement paredat i el de planta baixa diàfana. A més, es proposen certes extensions al mètode. Per tal de validar FAST, es tria l'escenari de dany real corresponent al terratrèmol de Lorca (2011) com a patró de comparació, malgrat la seva impulsivitat i directivitat. Per definir els paràmetres de entrada corresponents al cas d'estudi, cal recopilar prèviament la informació concernent al senyal sísmica, l'escenari de dany i les característiques del parc construït. Per tant, es porta a terme una revisió exhaustiva de les normes sísmiques històriques a Espanya i una anàlisi crítica de la norma sísmica espanyola actual (NCSE-02) comparant-la amb altres normes actuals de referència, com l'Eurocodi 8, fonamentat en el concepte d'acompliment. També es fa èmfasi a les provisions que no garanteixen el disseny per capacitat i que, per tant, poden provocar mecanismes de col·lapse fràgils o afavorir la interacció de la estructura amb els envans. A més, es discuteix sobre la restricció del coeficient de ductilitat de les estructures de bigues planes ja que es una qüestió que no aborden la majoria de les normes. Els resultats obtinguts mitjançant l'anàlisi de casos d'estudi mostren que aquesta restricció resulta obsoleta a les normes actuals. Finalment, FAST s'aplica al cas del terratrèmol de Lorca, obtenint prediccions de dany mitjà per a diferents combinacions del paràmetres de entrada. Els resultats mostren una coincidència acceptable entre la predicció i els danys reals. FAST confirma que la causa principal de la pràctica absència de col·lapses (davant un terratrèmol amb PGA triple que la típica de projecte) cal buscar-la en la contribució estructural dels envans.
Gómez Martínez, F. (2015). FAST simplified vulnerability approach for seismic assessment of infilled RC MRF buildings and its application to the 2011 Lorca (Spain) earthquake [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/54780
TESIS
Premiado

Linear genomes end in characteristic structures consisting of repetitive DNA and proteins: the telomeres. These play two critical roles: on one hand they avoid the of loss of genetic information due to the incomplete replication of the chromosome ends and on the other, they provide capping structures for chromosome termini, differentiating them from double strand breaks. Telomeres contain specialized proteins (the shelterin complex), as well as proteins present elsewhere on the chromosomes (chromatin remodelling, DNA damage repair and response factors). Interestingly, several DNA damage factors are required for proper telomere maintenance, drawing a thin line between telomere protection and their recognition as broken DNA ends. Loss of telomere integrity has severe consequences for the cell, namely it can induce replicative senescence and cellular aging, or it can contribute to tumorigenesis. How telomeres are capped and how they are perceived by the cell when they become dysfunctional is essential for our understanding of the contribution of loss of telomere integrity to aging and disease. In order to unravel new factors involved in telomere maintenance, siRNA screens were performed. The optimization process has confirmed both telomeric foci and telomere dysfunction-induced foci (TIFs) as suitable readouts and the screens performed generated a list of potential candidate genes involved in telomere biology. Although some of the candidate genes tested in this work failed the validation process, other genes deserve further analysis. In addition this work also studied the role of several DNA damage factors at uncapped telomeres. Furthermore, BRCA1, CtIP and EXO1 were found to be critical for the formation of end-to-end fusions generated after TRF2 inactivation. The requirement of this proteins in this process, suggests that not only that not only the classical non-homologous end joining (C-NHEJ) pathway is active at TRF2-depelted telomeres, but emphasises the multiplicity of mechanisms that act to repair dysfunctional telomeres.

The debate on "Loss and Damage" (L&D) has gained traction over the last few years. Supported by growing scientific evidence of anthropogenic climate change amplifying frequency, intensity and duration of climate-related hazards as well as observed increases in climate-related impacts and risks in many regions, the "Warsaw International Mechanism for Loss and Damage" was established in 2013 and further supported through the Paris Agreement in 2015. Despite advances, the debate currently is broad, diffuse and somewhat confusing, while concepts, meth ods and tools, as well as directions for policy remain vague and often contested. This book, a joint effort of the Loss and Damage Network - a partnership effort by scientists and practitioners from around the globe - provides evidence-based insight into the L&D discourse by highlighting state-of-the-art research conducted across multiple disciplines, by showcasing applications in practice and by providing insight into policy contexts and salient policy options. This introductory chapter summarises key findings of the twenty-two book chapters in terms of five propositions. These propositions, each building on relevant findings linked to forward-looking sugges tions for research, policy and practice, reflect the architecture of the book, whose sections proceed from setting the stage to critical issues, followed by a section on methods and tools, to chapters that provide geographic perspectives, and finally to a section that identifies potential policy options. The propositions comprise (1) Risk management can be an effective entry point for aligning perspectives and debates, if framed comprehensively, coupled with climate justice considerations and linked to established risk management and adaptation practice; (2) Attribution science is advancing rapidly and fundamental to informing actions to minimise, avert, and address losses and damages; (3) Climate change research, in addition to identifying physical/hard limits to adaptation, needs to more systematically examine soft limits to adaptation, for which we find some evidence across several geographies globally; (4) Climate risk insurance mechanisms can serve the prevention and cure aspects emphasised in the L&D debate but solidarity and accountability aspects need further attention, for which we find tentative indication in applications around the world; (5) Policy deliberations may need to overcome the perception that L&D constitutes a win-lose negotiation "game" by developing a more inclusive narrative that highlights collective ambition for tackling risks, mutual benefits and the role of Transformation.

The prediction of fatigue life and evaluation of onset and growth of matrix cracks and delamination for general composite laminates are studied analytically using theories of damage tolerance, residual modulus degradation and residual strength degradation. Damage onset including matrix cracks and edge delamination are predicted by using a total strain energy release rate criterion which accounts for interactive effects of matrix cracks and delamination. The analytical models for modulus degradation, matrix crack density and delamination size growth as function of fatigue stress and fatigue cycles are proposed. The proposed approach provides four choices for predicting tension-tension fatigue life and for assessing fail-safety for structures made of composite laminates. The direct relation of physical damage to fatigue life and analytical equations for calculating residual elastic moduli E$ rm{ sb1, E sb2, v sb{12}}$ and G$ sb{12}$ in terms of fatigue load and fatigue cycles are proposed. The proposed approach enables prediction of fatigue behaviour of general laminates using experimental data of a basic lay-up such as unidirectional laminate. The finite element technique was utilized to model the fatigue failure process of notched laminates. A simple example of a laminate with a central hole under tension-tension fatigue loading was performed.

The rapid spread and increasing affordability of sensors, are encouraging the government and stake-holders to instrument important infra-structures and structures. These sensors generate vast amount of data which can be used in real-time health monitoring of the instrumented structures by using damage identification methods. A significant component of structural health monitoring is damage identification methods which process the data with the purpose of detecting damages in the structures. One of these methods with a theoretical background is the statistical subspace damage identification method (SSDI). The overarching goal in this thesis is to close the gap between theory and practice, in order to have a method with a strong theoretical background and a credible applicability at the same time. In order to achieve this goal several contributions are motivated in this thesis, which are presented as follows: Firstly, the effect of two challenges faced in the damage detection of structures under real test conditions, namely the measurement noise and duration (length), are theoretically evaluated. It is demonstrated that the measurement noise and length have considerable influence on the statistical subspace damage detection method and they need to be considered based on these proposed theories. Secondly, the statistical subspace damage localization (SSDL) method, is assessed for the first time, in localizing the damage of a real experimental structure, i.e. the Yellow frame, established on the course of this research at UBC. Several methods and theories are developed in order to enable this method in identifying the damage under real test conditions. It was demonstrated that by employing the proposed theories, the SSDL method can robustly locate the damage in a real structure such as the Yellow frame. Finally, two indexes are proposed in predicting the detectability of damage in each element of a structure. These indexes provide valuable information on the sensitivity of SSDL method to the damage in each element. All the proposed theories and methods are demonstrated theoretically; subsequently, they are verified by simple and sophisticated analytical models, and finally, they are validated by real-test data.
Applied Science, Faculty of
Civil Engineering, Department of
Graduate

In the past 40 years, floods have become a bane of Mozambique’s inhabitants and economy. The latest of them, caused by the cyclone Idai, has devastated the area resulting in loss of life and property. It was estimated that around 715 000 hectares of farmland was destroyed as a result of the cyclone. The main goal of this thesis was to assess the extent of the flooding and to determine the types of land cover that were affected. This was done in Google Earth Engine, using SAR change detection on Sentinel 1 data to create a mask for the flooded areas, followed by a supervised image classification on Sentinel 2 data to identify the types of land cover that were flooded. Two classifications were done, using imagery from early periods of the country’s plant growing season and later periods of the same season, respectively. The results of both classifications were below standard, with the main problems stemming from difficulties with differentiating between agriculture and roads along with agriculture and vegetation. Multiple ways to improve the results and avoid the errors in future similar projects were discussed, including using multi temporal data and utilizing a road map for the area to create a large amount of training points for the classification. In conclusion, while the results were not as good as was envisioned, the thesis provided ample opportunity to analyze errors and to theorize methods for improving future work.

Changes in load characteristics, deterioration with age, environmental influences and random actions may cause local or global damage in structures, especially in bridges, which are designed for long life spans. Continuous health monitoring of structures will enable the early identification of distress and allow appropriate retrofitting in order to avoid failure or collapse of the structures. In recent times, structural health monitoring (SHM) has attracted much attention in both research and development. Local and global methods of damage assessment using the monitored information are an integral part of SHM techniques. In the local case, the assessment of the state of a structure is done either by direct visual inspection or using experimental techniques such as acoustic emission, ultrasonic, magnetic particle inspection, radiography and eddy current. A characteristic of all these techniques is that their application requires a prior localization of the damaged zones. The limitations of the local methodologies can be overcome by using vibration-based methods, which give a global damage assessment. The vibration-based damage detection methods use measured changes in dynamic characteristics to evaluate changes in physical properties that may indicate structural damage or degradation. The basic idea is that modal parameters (notably frequencies, mode shapes, and modal damping) are functions of the physical properties of the structure (mass, damping, and stiffness). Changes in the physical properties will therefore cause changes in the modal properties. Any reduction in structural stiffness and increase in damping in the structure may indicate structural damage. This research uses the variations in vibration parameters to develop a multi-criteria method for damage assessment. It incorporates the changes in natural frequencies, modal flexibility and modal strain energy to locate damage in the main load bearing elements in bridge structures such as beams, slabs and trusses and simple bridges involving these elements. Dynamic computer simulation techniques are used to develop and apply the multi-criteria procedure under different damage scenarios. The effectiveness of the procedure is demonstrated through numerical examples. Results show that the proposed method incorporating modal flexibility and modal strain energy changes is competent in damage assessment in the structures treated herein.

Changes in load characteristics, deterioration with age, environmental influences and random actions may cause local or global damage in structures, especially in bridges, which are designed for long life spans. Continuous health monitoring of structures will enable the early identification of distress and allow appropriate retrofitting in order to avoid failure or collapse of the structures. In recent times, structural health monitoring (SHM) has attracted much attention in both research and development. Local and global methods of damage assessment using the monitored information are an integral part of SHM techniques. In the local case, the assessment of the state of a structure is done either by direct visual inspection or using experimental techniques such as acoustic emission, ultrasonic, magnetic particle inspection, radiography and eddy current. A characteristic of all these techniques is that their application requires a prior localization of the damaged zones. The limitations of the local methodologies can be overcome by using vibration-based methods, which give a global damage assessment. The vibration-based damage detection methods use measured changes in dynamic characteristics to evaluate changes in physical properties that may indicate structural damage or degradation. The basic idea is that modal parameters (notably frequencies, mode shapes, and modal damping) are functions of the physical properties of the structure (mass, damping, and stiffness). Changes in the physical properties will therefore cause changes in the modal properties. Any reduction in structural stiffness and increase in damping in the structure may indicate structural damage. This research uses the variations in vibration parameters to develop a multi-criteria method for damage assessment. It incorporates the changes in natural frequencies, modal flexibility and modal strain energy to locate damage in the main load bearing elements in bridge structures such as beams, slabs and trusses and simple bridges involving these elements. Dynamic computer simulation techniques are used to develop and apply the multi-criteria procedure under different damage scenarios. The effectiveness of the procedure is demonstrated through numerical examples. Results show that the proposed method incorporating modal flexibility and modal strain energy changes is competent in damage assessment in the structures treated herein.

This thesis investigates the behaviour and failure of simple and complex structures using the structural health monitoring system (SHM). The work focuses on Acoustic Emission (AE) to detect, characterise and locate damage within metallic and composites structures under a fatigue loading regime. The work was divided into two main areas of research: 1. Damage Characterisation Damage detection utilising AE was conducted through an extensive experimental programme in large-scale carbon fibre composite structures. Different assessment techniques were used to assess different damage mechanisms within the structure under fatigue failure. The source mechanisms characterisation in a large scale fatigue specimen was performed using a novel parameter correction technique (PCT). This is a significant advance, offering (in large scale structures) more reliable source characterisation. 2. Damage Localisation Experimental investigations were undertaken to assess the novel AE location technique proposed in this work in a variety of structures. The new technique, known as Automatic Delta T mapping technique (Automatic DTM), provides an accurate, easy to use, fast and reliable damage localisation technique.

This research concentrates on damage ship stability and means for assessing dynamic ship performance in this state. A consolidation of many approaches for tackling damage ship dynamics has been undertaken, culminating in the development of a numerical tool for simulating ship behaviour while accounting for progressive flooding and the ensuing effects of floodwater motion. General features that have been accounted for in a new purposely developed numerical program PROTEUS3 include the following: Linear concepts regarding intact ship hydrodynamics based on strip theory and Rankine source method (RSM). These are further utilised by convolution and spectral transformations in deriving relevant time domain force realisations. Non-linear excitation/restoring forces calculated from pressure integration up to the instantaneous undisturbed wave profile. Non-linearities in hydrodynamic properties arising from variation of mean underwater geometry due to occurrence of non-stationary asymm etries in mass distribution are taken into account by a database approach. Forward speed in arbitrary heading. Progressive flooding through a ship with any internal subdivision and floodwater motion simulations based on free-mass-on-potential-surface (FMPS) model. Non-linear treatment of the effects of cargo shift or floodwater motions on the overall ship dynamic behaviour. The underlying modelling has been explained by rigorous derivation of all the relevant equations from first principles. Validity of the model has been tested comprehensively through comparison with available physical model tests data. A thorough investigation on the new effects of modelling advancements concerning the accuracy of the developed model has been undertaken and the results are presented and discussed. Despite the introduction of simplifying assumptions concerning floodwater behaviour, the predictions show consistency with physical experimental data. It is believed that this pragmatic approach constitutes a very efficient tool for predictions of vessel performance in extremely adverse conditions. This effectiveness has been demonstrated by undertaking forensic analysis of two of the most controversial accidents of the last two decades, namely the loss of MV Derbyshire and the NW Estonia disaster.

Ongoing developments in improving ship safety indicate the gradual transition from a compliance-based culture to a sustainable safety-oriented culture. Sophisticated methods, tools and techniques are demanded to address the dynamic behaviour of a ship in a physical environment. This is particularly true for investigating the flooding phenomenon of a damaged ship, a principal hazard endangering modern ships. In this respect, first-principles tools represent a rational and cost-effective approach to address it at both design and operational stages. Acknowledging the criticality of ship survivability and the various maturity levels of state-of-the-art tools, analyses of the underlying uncertainties in relation to relevant predictions become an inevitable component to be addressed. The research presented in this thesis proposes a formalised Bayesian approach for quantifying uncertainties associated with the assessment of ship survivability. It elaborates a formalised procedu re for synthesizing first-principles tools with existing knowledge from various sources. The outcome is a mathematical model for predicting time-domain survivability and quantifying the associated uncertainties. In view of emerging ship life-cycle safety management issues and the recent initiative of "Safe Return to Port", emergency management is recognised as the last remedy to address an evolving flooding crisis. For this reason, an emergency decision support framework is proposed to demonstrate the applicability of the presented Bayesian approach. A case study is enclosed to elucidate the devised shipboard decision support framework for flooding-related emergency control. Various aspects of the presented methodology demonstrate considerable potential for further research, development and application. In an environment where more emphasis is placed on performance and probabilistic-based solutions, it is believed that this research has contributed positiv ely and substantially towards ship safety, with particular reference to uncertainty analysis and ensuing applications.

Background: Current evidence indicates that DNA damage response (DDR) is a highly complex process that involves various pathways working in an orchestrated and interwoven manner in response to different types of damage to DNA. Although specific defects of DDR remain to be deciphered in cancer as a general, there is certainly an undeniable relationship between a particular dysfunction of DDR and the phenotype of tumour [1, 2]. It has been demonstrated that familial forms of breast and ovarian cancer are characterised by defects in one of the main mechanisms of DDR homologous recombination (HR) as a result of germline loss-of-function mutations in one of HR modifying genes, such as BRCA1 and BRCA2 [1, 3, 4]. Defects of genes involved in other DDR pathways are also associated with specific types of cancers; for instance hereditary non polyposis colorectal cancer (HNPCC) is strongly associated with specific mutations in the DNA mismatch repair pathway. Several previous studies have demonstrated that impaired DDR play a fundamental role in the pathogenesis and behaviour of breast cancer (BC). However, characterisation of this complex process, the expression and co-expression of the key proteins involved in the various DDR pathways and their prognostic significance in BC remain to be defined. In BC, it is reported that genes involved in DNA double strand breaks (DSB) repair are the most important. Two main pathways are involved in the repair of DNA-DSB; HR and Non Homologous End Joining (NHEJ) [3]. The common characteristics of global DDR are multiple genes induction directly associated with sensing and repair of DNA, arrest of cell cycle, and cell division inhibition. As a result DDR process does not only include genes activation involved in damage sensing as well as repair but additionally genes involved in control of cell-cycle [5]. Despite the fact that DDR may possibly involve activation of several pathways (such as SUMOylation (SUMO)) [6, 7] and many genes are engaged in different overlapping mechanisms, each pathway is characterised by activation and expression of a unique set of genes. This could allow discovering the active or aberrant pathway in a given tumour [1, 4, 5]. This study explores the hypothesis that investigation of alterations in the different pathways of DNA-DSB, may contribute to the characteristics of BC. Therefore, the aim was to perform a comprehensive profiling of key proteins involved in the different DNA-DSB repair pathways in the different molecular classes of BC. This approach aims to address the inherent problems arising from the complexity of DDR mechanism in BC with the potential of discovering a key pathway that is active or inactive in specific forms of BC that can be helpful to identify DNA repair status in individual BC patients. Method: The study cohort comprises three BC groups: A) Large series of unselected primary sporadic operable invasive tumours (n=1904) in addition to B) 386 cases of oestrogen receptor (ER) negative tumours and C) a well-characterised series of BC from patients with known BRCA1 germline mutations (n=24). The proteins investigated in this study are known to participate in different DNA-DSB repair pathways including, DNA damage sensors (ATM and ATR), HR repair (BRCA1, BARD1, Rad51, γH2AX and SMC6L1), DNA damage checkpoint signalling protein (CHK1 and CHK2), NHEJ repair (KU70/KU80, and DNA-PK), and SUMO (PIAS1, PIAS4, and UBC9). Because subcellular localisation of DDR proteins may affect their function, two markers that have role in nuclear transport in the cell were examined (NPM and KPNA2). The expression of these proteins was assessed using the well-established immunohistochemical technique utilising tissue microarray technology. The expression of proteins was further evaluated in various cell lines; BRCA1 deficient HeLaSilenciX® cells, and control BRCA1 proficient HeLaSilenciX®, MDA-MB-436 (BRCA1 deficient), and MCF-7 (BRCA1 proficient and ER+) using Reverse Phase Protein Microarray (RPPA). Results: Both cytoplasmic and nuclear expression was observed for expression of Rad51, SMC6L1, BRCA1, BARD1; (HR markers), PIAS1, UBC9 (SUMO markers), γH2AX (DNA-DSB marker) and CHK1 (checkpoint signalling protein). In contrast, both NHEJ markers and most of the DNA damage sensors (ATM and ATR), CHK2 and PIAS4 were mainly expressed in the nucleus. Generally, tumours that showed positive cytoplasmic/negative nuclear expression such as CHK1, PIAS1, Rad51, and BRCA1, and positive nuclear NHEJ markers showed an association with a poor outcome and adverse prognostic characteristics including high histologic grade, high mitotic frequency, high nuclear pleomorphism and larger tumour size in addition to ER negativity, and triple negative breast cancer (TNBC). Conversely, nuclear+/cytoplasmic- expression showed an association the better outcome. Interestingly, ATM protein expression showed no association with the expression of the two NHEJ markers, whereas ATR showed an association with cytoplasmic expression of BRCA1 and BARD1 and was positively associated with NHEJ markers. In non-TNBC, tumours showing BRCA1-/KU70/KU80- phenotype had worse breast cancer specific survival (BCSS) than positive expression (P<0.0001), whereas in the TN cohort,complex of KU70/KU80-&DNA-PK+ had the worst BCSS (P=0.001), and both are independent prognostic markers for BC. KPNA2, but not NPM was highly associated with poor BCSS (P<0.0001). At least one of nucleocytoplasmic transport markers (NPM or KPNA2) was significantly associated with the subcellular localisation of the most of the markers that showed cytoplasmic expression including SMC6L1, γH2AX, BRCA1, BARD1, UBC9, PIAS1 ,Rad51 and CHK1. RPPA was used to investigate the protein expression in different cell lines, although the correlation between RPPA and IHC was not significant, the results of RPPA were consistent with that demonstrated by IHC further supporting the finding of the current study. Conclusion: This study highlight the complexity of DDR related proteins and the overlap between different pathways involved in DDR. The finding of this study may help in the classification of BC and therefore, targeting active pathways in the development of drugs would enhance better patients’ outcomes. Major prognostic and predictive variables can be very important in choosing suitable treatment plans, identifying the risk of recurrence and classifying patients for clinical trials. Our results show that the HR- repair marker Rad51, complex of HR and NHEJ repair markers (BRCA1&KU70/KU80) in non-TNBC, and a complex of NHEJ markers (KU70/KU80&DNA-PK) are all independent prognostic markers for BC. In addition to expression, subcellular localisation of DDR proteins appeared to be a major factor in their role. Particularly, HR repair markers (but not NHEJ) showed worse features of cytoplasmic location of expression, whereas nuclear expression was associated with more favourable features. Finally, the results of this study provide further evidence to support combined use of IHC with the parallel analytic capability of protein microarray RPPA to investigate protein alterations in human tumours.

Kyoto University (京都大学)
0048
新制・課程博士
博士(工学)
甲第14135号
工博第2969号
新制||工||1441(附属図書館)
26441
UT51-2008-N452
京都大学大学院工学研究科社会基盤工学専攻
(主査)教授 杉浦 邦征, 准教授 白土 博通, 准教授 宇都宮 智昭
学位規則第4条第1項該当

This project that has been executed in collaboration with Saab aerostructures deals with how three materials, aluminum, titanium and corrosion resistant steel react when they are affected by different energy levels. These energy levels serve the purpose of representing damages that can happen in storage and handling to components used in production. A literature study was made to gather information regarding the treated materials as well as some methods that can be used to test a materials property. The goal of the project is to create a tool for Saab to use in their production in order to first estimate the energy levels that created a mark on a material and secondly evaluate if a crack can be suspected, by consequence evaluate if a NDT (non-destructive test) is required. The experiment was executed as such that all of the materials were put through drop-tests simulating different energy levels, with two different strikers, blunt and sharp, and then the materials were examined. Non-destructive testing was made on all of the marks made on the different materials using penetrant- or eddy current-method to see if there were any cracks formed in the material after impact. The experiment did not show signs of any cracks from the tested energy levels. However, it showed that crack propagation is highly dependent on the shape of the striker. To make the experiment more reliable and give a better result more energy levels would have needed to be tested. Also, a large number of different strikers and more non-destructive testing methods would have to be used.
Detta projekt som har utförts i samarbete med Saab aerostructures behandlar hur tre material, aluminium, titan och rostfritt stål reagerar när de blir utsatta för olika energinivåer. Dessa energinivåer ska simulera skador som kan uppkomma under hantering och förvaring av komponenter i Saabs produktion. En litteraturstudie har utförts för att samla information om materialen samt om några testmetoder som kan användas för att utvärdera ett materials egenskaper. Målet med projektet är att få fram ett tillvägagångssätt för Saab att i första hand uppskatta energinivåerna bakom ett slagmärke i ett material, därefter bedöma ifall en sprickinitiering kan misstänkas och därmed avgöra huruvida komponenter som utsatts för energinivåer behöver undergå oförstörande provning eller om de kan fortsätta användas i produktionen utan någon form av testning. Ett experiment utfördes genom att utsätta samtliga av materialen för dropp-tester med olika energinivåer med två olika slagdon, trubbigt och spetsigt, för att sedan kunna undersöka om sprickor hade propagerats. Oförstörande provning gjordes på alla simulerade skador antingen via penetrantmetoden eller virvelströmsprovning, för att se om det bildats sprickor i de olika materialen efter slaget. Experimentet visade inte på några sprickor vid de testade energinivåerna. Däremot såg man att sprickinitiering beror bland annat på slagdonets utformning, där en skarpare form ökade risken för sprickor. För att experimentet ska bli mer pålitligt och ge ett bättre resultat hade fler energinivåer behövt testas, en större variation av slagdon hade behövt användas samt att man hade behövt använda fler typer av oförstörande provning.

This research presents a step forward in the area of structural health monitoring by developing the scientific basis for a method to detect and locate damage in asymmetric building structures accurately and efficiently. The method is based on the changes in the vibration characteristics of asymmetric buildings such as natural frequencies and associated mode shapes. The thesis first investigated the difference in vibration behavior between symmetric and asymmetric buildings and compared the capability of different damage detection methods that uses the vibration characteristics. Then a modified method (MMSE) and an improved method (MCA-DI) were proposed based on the comparative study and verified through experimental testing of a laboratory scale asymmetric setback structure model.

" Estimating Life Loss for Dam Safety Risk Assessment" explores the need for a new life-loss model in dam safety risk assessment, historical foundations on which that model can be built, and issues that are critical for a successful life-loss model to address. After critiquing existing life-loss models, the work presents a summary of historical insights that were derived by characterizing flood events on the level of subpopulations at risk, using nearly l 00 carefully defined variables. Building upon both conceptual and historical insights, the work culminates by presenting the conceptual basis for a new life-loss model that remains under development. Chapter I introduces the topic of dam safety risk assessment and the central role that life-loss estimation plays in that field. Chapter II discusses important preliminary considerations in model development. Chapter Ill provides a detailed review of previous life-loss models that pertained to floods, including a critique of each. Chapter IV explores the DeKay-McClelland model in detail and raises serious concerns regarding its future use. Chapter V defines nearly l 00 variables and their respective categories for use in characterizing flood events. Chapter VI provides a detailed outline of historical insights that relate to flood events in one of 18 logical categories. Chapter VII proposes the framework for a new conceptual life-loss model-a model that is still under development and has yet to be refined or offered for testing-with sufficient details to indicate how it was developed and how it might be used. Chapter VIII provides a summary, conclusions, and recommendations for future research. Appendices A through D provide material related to over 900 pages of unpublished working documents developed while characterizing 38 flood events and nearly 200 subpopulations at risk. Appendix E offers a summary of existing software that, given additional development, might prove useful to life-loss estimation in dam safety risk assessment.

Chemotherapy treatment in premenopausal women has been linked to premature ovarian failure (POF), and hence infertility, through ovarian follicle loss. The exact mechanisms that lie behind this loss are unclear and so the action of two commonly used chemotherapeutic agents were compared here. Cisplatin is a DNA cross-linking agent commonly used in the treatment of ovarian, lung and bladder cancers, while the anthracycline doxorubicin is commonly used to treat leukaemia and breast cancer. Neonatal mouse ovaries were cultured in vitro and exposed to cisplatin or doxorubicin in order to determine their effects on primordial and early growing follicles. Both drugs caused a dose dependant follicle loss but targeted different cell types. Cisplatin caused a significant increase in follicles with unhealthy oocytes; furthermore primary stage follicles were the follicle class most affected (up to 98% classified as unhealthy compared with 13% in control, p<0.001). In contrast, doxorubicin caused a significant increase in follicles with unhealthy granulosa cells and affected all follicle stages present. When the mechanism of cell death was further investigated, apoptosis was the main pathway through which these drugs cause ovarian cell death. Doxorubicin in particular caused a significant increase in apoptosis of ovarian somatic cells including the granulosa cells and stroma. Imatinib mesylate, a tyrosine kinase inhibitor which is also used as a chemotherapeutic agent, has been implicated as a potential therapy to block the ovotoxic effects of cisplatin. Results here confirm this finding (29% of follicles classified as unhealthy in the cisplatin only group compared to 8% in the cisplatin and imatinib co-treatment group, p<0.001) and found further, that imatinib was unable to protect against doxorubicin-induced damage (28% of follicles classified as unhealthy in the doxorubicin treated group compared to 19% in the doxorubicin and imatinib cotreatment group). Imatinib treatment alone in newborn ovaries caused a significant increase in the number of follicles present at the end of culture compared to control (402±43 in the imatinib group compared to 188±34 in control, p<0.001), which is likely due to an effect on follicle formation. In conclusion, the work presented in this thesis demonstrates drug specific actions of cisplatin and doxorubicin on the mouse ovary. This suggests that any therapy designed to confer ovarian protection in the future may have to be tailored to be drug specific.

Acute myeloid leukaemia (AML) is a heterogeneous myeloid malignancy characterized by clonal expansion of abnormal/immature hematopoietic precursor cells in the bone marrow. A side compartment in the BM niche consists of abnormal, quiescent cells, which are called dormant leukemic initiating cells (DLICs). Patients with AML tend to respond well to remission induction chemotherapy, but relapse is common because current therapies cannot completely eradicate leukemic cells. It is widely accepted that CD34+CD38− DLICs are more resistant to chemotherapy and that they contribute to drug resistance and relapse of AML to a greater extent than progenitor CD34+CD38+ cells. DLICs have been extensively characterised, but they remain a critical area of investigation for clinical research because of the low prevalence of DLICs and similarity to normal HSCs. A model of dormancy in vitro that shows most of the features of DLICs had previously been established in the Nottingham Haematology Group. This study used this model and aimed to investigate whether the response to DNA damage was different in dormancy-enriched cells compared to cycling leukemic cells following chemotherapy. The amount of DNA damage was assessed up to 24 hours pre- and post- drug treatment using the neutral Comet assay. Lower levels of damage were observed in dormancy-enriched cells following etoposide (ETO) treatment at 4 hours (p = 0.04), although this switched at the 24 hour time point where accumulated DNA double-stranded breaks (DSBs), in dormancy-enriched KG1a cells were associated with a higher percentage of viable cells. DNA damage response cascade markers in both dormancy-enriched and cycling cells showed phosphorylation by flow cytometry (phospho-H2AX139, pATM-S1981, H2AX142, and pChk-Thr68) in response to conventional AML chemotherapy. Significantly lower levels of cleaved PARP-Asp214 and active caspase 3 were observed in dormancy-enriched cells treated with ara-c (p = 0.0001) or ETO (p = 0.0001) at 24 hours, strongly indicating that survival responses are activated in dormancy-enriched cells. Induction of 53BP1 foci, the hallmark of non-homologous end joining (NHEJ) was observed following treatment with ara-c (p = 0.038) and ETO (p = 0.049) in dormancy-enriched cells, indicating the NHEJ repair pathway is the preferred mechanism for DSB repair. At the molecular level, BTG2 expression was involved in the DNA damage response. Significant induction of BTG2 was detected in cycling treated cells with ETO for 24 hours. In conclusion, this study provides evidence that phosphorylation of H2AX139 and H2AX142 is a key response marker that may explain the mechanism underlying the drug resistance of DLICs and induction of repair. Therefore, results of this study may help in devising novel treatment strategies for AML that target H2AX142 of DLICs to permanently eradicate all leukemic cells and improve overall survival.

To acknowledge and account for the uncertainties present in civil engineering applications is an area of major importance and of continuing research interest. This Thesis focuses on an application of Bayes' inference rule to evaluate the probability of damage in structures, using measured modal parameters and a set of possible damage states. The hypothesis is that observed changes in dynamic characteristics are due to damage accumulation over time. The main objective is to identify the most likely damage scenario from a set of previously defined damage states. These are characterized in terms of vectors, θi, the components of which are the parameters, θij, that are associated with the stiffness contribution, Kj, from each substructure undergoing damage. These stiffness matrices are uncertain as a result of random geometric and material properties. For different combinations of the damage parameters and realizations of the random variables, the modal parameters are calculated solving the basic eigenvalue problem. The results are used to calculate the statistics of the parameters given a specific damage state, the likelihood functions, as these are needed to calculate the probability of a given a set of measurements given a damage state. Each damage state Di is associated with a prior probability P(Di). In order to calculate its posterior probability, given a set of measurements, a Bayesian updating is implemented, in which the prior probability is updated by means of the likelihood functions, f(r|Di), which represent the probability density function of the modal parameter, r, given the damage state, Di. This Thesis discusses the effectiveness of the approach in identifying a particular damage state referred to as damage scenario. It is shown that measurement of multiple modal parameters is required to identify, quickly and with confidence, a given damage state. The discussion also considers the effect of error in the measurements, and the number of repeated measurements that are required to achieve a substantial confidence as to the presence of a particular damage state. Ranking of the estimated probabilities, after a set of measurements, offers guidance to the engineer as when and where to conduct a direct inspection of the structure.

Moisture-induced damage is one the major causes of deterioration of asphalt pavements and extensive research has been conducted on this topic. Theoretical and experimental results have led the researchers to believe that moisture-induced damages are caused mainly by the generation of pore water pressure in asphalt mixtures when traffic passes over a pavement. The Moisture Induced Sensitivity Tester (MIST) has been recently developed to simulate the phenomenon of repeated pore pressure generation and deterioration in the laboratory. The objective of this study was to evaluate moisture-induced damage in typical Maine Department of Transportation (DOT) asphalt mixes, with the use of MIST, pre and post testing, and analysis of data. The MIST was used to condition Hot Mix Asphalt (HMA) samples that were compacted from eight typical Maine DOT mixes, with different types of aggregates and asphalt binder. A modified Dynamic modulus test in Indirect Tensile Mode was used for the determination of damage. A layered elastic model, along with a fatigue-cracking criterion, was utilized to assess the total impact on the pavement lives. Monte Carlo analysis was conducted to determine the distribution of number of repetitions to failure of pavements that are subjected to moisture damage. The major conclusions are that most of the mixes are likely to experience a reduction in their life due to the effect of moisture and that the Micro-Deval and the fine aggregate absorption test results can be related to such damage. A composite factor, consisting of both of these test results, is recommended for regular use by the DOT to screen mixes with high moisture damage potential.

This thesis examines the role of Acoustic Emission (AE) as a non-destructive testing technique for concrete structures. The work focuses on the development of experimental techniques and data analysis methods for the detection, location and assessment of AE from the failure of plain and reinforced concrete specimens. Four key topics are investigated:

This work is concerned with the damage tolerance assessment of laminated composite structures used in ship structures. An intensive review has been carried out with regard to current experimental, analytical and numerical work on both laminates and structural elements. Particular attention has been focused on the problem of damage due to delamination and its structural consequences. Strength assessments of top hat stiffeners and tee joints has been carried out with a view to identifying regions most susceptible to delaminations. It has been shown that such regions are contained within the curved region of the overlaminate in both types of structural elements. Strain energy release rates and J-integral values have been calculated for specific cracks to determine their likelihood of propagation under a variety of loading conditions. Overall, a number of conclusions have been drawn with regard to single-skin marine FRP structures. For example, both the strength - and the energy - based approaches have predicted that a tee joint subjected to a 45 degree pull-off load, delaminations which are deep within the overlaminate are more likely to propagate than those close to the surface.

Approved for public release; distribution in unlimited.
An imaging radar, like ISAR, offers a combatant the capability to perform long range surveillance with high quality imagery for positive target identification. Extending this attractive feature to the battle damage assessment problem (BDA) gives the operator instant viewing of the target's behavior when it is hit. As a consequence, immediate and decisive action can be quickly taken (if required). However, the conventional Fourier processing adopted by most ISAR systems does not provide adequate time resolution to capture the target's dynamic responses during the hit. As a result, the radar image becomes distorted. To improve the time resolution, time-frequency transform (TFT) methods of ISAR imaging have been proposed. Unlike traditional Fourier-based processing, TFT's allows variable time resolution of the entire event that falls within the ISAR coherent integration period to be extracted as part of the imaging process. We have shown in this thesis that the use of linear Short Time-Frequency Transforms allows the translational response of the aircraft caused by a blast force to be clearly extracted. The TFT extracted images not only tell us how the aircraft responds to a blast effect but also provides additional information about the cause of image distortion in the traditional ISAR display.

Thesis (M.S. in Combat Systems Technology)--Naval Postgraduate School, Dec. 2004.
Thesis Advisor(s): Brett H. Borden, Donald L. Walters. Includes bibliographical references (p. 97-98). Also available online.

It is only a matter of time before components working in high temperature environments fail due to creep. Design for creep is therefore of vital importance to maximize the lifetime of components and reduce costs that may arise from maintenance and replacement of components. This thesis aims to use metallographical methods and finite element modeling to assess creep damage in a hydrogen reformer. The decommissioned reformer, made of Fe-Ni-Cr alloys, was investigated thoroughly via replica testing, hardness measurements as well as finite element modeling of the welds. An extended literature review was performed to gain a better understanding of creep in Fe-Ni-Cr alloys, welds and the modeling of creep generally. The microstructures of samples from the reformer were analyzed and mapped out in terms of creep damage which were then compared to a creep analysis of the welds with a simulation time of 100 000 h. The FE results yielded high stresses and creep strains with a maximum of 0.95% in the boundaries of the welds which gave realistic representations of strain distributions when compared to the metallographical results. Hardness measurement indicated that a relatively narrow zone with altered mechanical properties is present along the weld boundaries. This area, called the heat affected zone, was found to be most affected by creep with microcracks reaching maximum lengths of 2 mm. The creep strains obtained from simulation did not fall in line with the observed creep damage, it was thus concluded that a material model that considers tertiary creep would yield a more realistic representation in FEM for Fe-Ni-Cr alloys.
Det är bara en tidsfråga innan komponenter som arbetar i högtemperaturförhållanden misslyckas pga kryp. Att designa med avseende på kryp är därmed viktigt för att maximera livslängden och reducera kostnader som kan komma från underhåll och från utbyte av komponenter. I detta examensarbete används metallografiska metoder och finita element modellering för att bedöma krypskador i en vätgasreformer. Vätgasreformern, som är tillverkad i Fe-Ni-Cr legeringar, togs ur drift och undersöktes metallografiskt med hjälp av replikprovning och hårdhetsprovning samt med finita element modellering av svetsar. En djupgående litteraturstudie utfördes för att öka förståelsen av kryp, specifikt i Fe-Ni-Cr legeringar och även modellering av kryp generellt. Mikrostrukturen från utvalda provbitar undersöktes och krypskador kartläggdes för att sedan jämföra med en krypanalys av svetsarna där 100 000 timmars kryp simulerades. Krypanalysen resulterade i höga spänningar och kryptöjningar upp till maximalt 0.95% i svetsgränserna vilket gav realistiska representationer av töjningsdistributionen jämfört med metallografiska resultaten. Hårdhetsmätningar indikerade att ett smalt område med förändrade mekaniska egenskaper fanns utmed svetsgränserna. Detta område, den värmepåverkade zonen, var mest utsatt för krypskador med mikrosprickor uppemåt 2 mm i längd. Kryptöjningar som erhölls från simuleringen gav inte en tillräckligt bra uppskattning av kryptöjningarna – de krypskador som observerades motsvarar lokalt högre töjning. Slutsatsen är att en materialmodell som tar hänsyn till tertiärkryp skulle i det här fallet ge en mer realistisk representation i FEM för Fe-Ni-Cr legeringar.

Incremental damage assessment is a tool used to assess the justification for expensive modifications of inadequate dams. The input data to incremental damage assessment are the output from the breach analysis and flood routing. For this reason, flood routing should be conducted carefully. Distorted results from the flood routing technique or unstable modeling of the problem will distort the results of an incremental damage assessment, because an error in the estimated incremental stage will cause a certain error in the estimated incremental damages. The objectives of this study were (1) to perform a comprehensive survey of the available dam break flood-routing techniques, (2) to evaluate the performance of commonly used flood-routing techniques for predicting failure and no-failure stage, incremental stage, average velocities, and travel times, and (3) to develop a set of recommendations upon which future applications of dam break models can be based. Flood-routing techniques that are evaluated cover dynamic routing as contained in DAMBRK, and kinematic, Muskingum-Cunge, and normal depth storage routing as contained in the Hydrological Engineering Center (HEC 1). These techniques were evaluated against the more accurate two-dimensional flood-routing technique contained in the diffusion hydrodynamic model (DHM). Results and errors from different techniques for different downstream conditions were calculated and conclusions were drawn. The effect of the errors on the incremental stage and the errors in the incremental stage were estimated. Overall, the performance of one-dimensional techniques in predicting peak stages, and assessing a two-feet criterion showed that DAMBRK did best, and normal depth storage and outflow did worst. This overall ranking matches the degree of simplification in representing the true flood-routing situation. However, in some circumstances DAMBRK performed worst, and normal depth storage and outflow outperformed either the Muskingum-Cunge or kinematic techniques. Thus, it is important to understand the specific performance characteristics of all the methods when selecting one for a flood-routing application.

Residents in urban areas depend on infrastructure systems to return to functionality quickly after disruptions from natural and man-made disasters to support their livelihood and well-being. This work seeks to improve the accuracy of infrastructure recovery time estimates by introducing mutually exclusive damage state modeling into the Graph Model for Operational Resilience (GMOR) and utilizing this capability for road recovery assessment in two case studies in the District of North Vancouver, British Columbia. The first case study also explores the recovery of water, wastewater, and power networks in the District, and demonstrates that power and road systems recover more slowly and are more variable in their recovery time than water distribution and wastewater collection systems. The second study specifically addresses important sections of road within the District and shows that intelligent prioritization of resource allocation for road repairs can improve recovery times by up to 37% compared to random ordering.
Graduate

碩士
國立臺灣海洋大學
海洋事務與資源管理研究所
96
Total of 352 fishing operations of Nanfangao fishing vessels during February 2007 to April 2007 were recorded by the questionnaires. The catch damage rates by dolphins and sharks were 33.24% and 22.44%, respectively. The depredation rates in number and weight by dolphins were 10.20% and 9.52%, while those rates by sharks were 2.10% and 2.22%, respectively. Moreover, the depredation index by dolphins and sharks were 4.60 and 0.88. It also indicated that the dolphins preferred to bite dolphin fish, yellowfin tuna and bluefin tuna, however sharks preferred to bite dolphin fish, oil fish and billfsih. Based on the annual yields of Nanfangao longline fishery. The total depredation loss by dolphin and shark of Nanfangao longline fishery were respective NT 86,726,089 and NT 17,100,649 dollars, which occupied 9.08% and 1.79% of total income of Nanfangao longline fishery, respectively.