Thèses sur le sujet « Bank failures – Models »

This paper examines banks in Missouri during the Great Depression in order to find the correct model specification for bank failure during economic downturns. The data set controls for a bank’s balance sheet, correspondent network, charters and memberships, county characteristics, and market share, and includes both Federal Reserve member and non-member banks. Using a probit model, it is concluded that the contractionary monetary policy employed by the St. Louis Federal Reserve did not help bank survival, as being a member of the Federal Reserve had no significant effect on a bank’s probability of survival. Additionally, while an increased network led to higher rates of bank survival, connections to Chicago show evidence of contagion risk. Finally, the paper concludes that for future model specification it is important to capture balance sheet, network, and environment characteristics, as leaving out certain information can lead to omitted variable bias.

Title from PDF of title page (University of Missouri--Columbia, viewed on March 10, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Thesis advisor: Dr. Robert M O'Connell. Includes bibliographical references.

The following dissertation contains two distinct empirical essays which contribute to the overall field of Financial Economics. Chapter 1, entitled “The Determinants of Dynamic Dependence: An Analysis of Commodity Futures and Equity Markets,” examines the determinants of the dynamic equity-commodity return correlations between five commodity futures sub-sectors (energy, foods and fibers, grains and oilseeds, livestock, and precious metals) and a value-weighted equity market index (S&P 500). The study utilizes the traditional DCC model, as well as three time-varying copulas: (i) the normal copula, (ii) the student’s t copula, and (iii) the rotated-gumbel copula as dependence measures. Subsequently, the determinants of these various dependence measures are explored by analyzing several macroeconomic, financial, and speculation variables over different sample periods. Results indicate that the dynamic equity-commodity correlations for the energy, grains and oilseeds, precious metals, and to a lesser extent the foods and fibers, sub-sectors have become increasingly explainable by broad macroeconomic and financial market indicators, particularly after May 2003. Furthermore, these variables exhibit heterogeneous effects in terms of both magnitude and sign on each sub-sectors’ equity-commodity correlation structure. Interestingly, the effects of increased financial market speculation are found to be extremely varied among the five sub-sectors. These results have important implications for portfolio selection, price formation, and risk management. Chapter 2, entitled, “US Community Bank Failure: An Empirical Investigation,” examines the declining, but still pivotal role, of the US community banking industry. The study utilizes survival analysis to determine which accounting and macroeconomic variables help to predict community bank failure. Federal Deposit Insurance Corporation and Federal Reserve Bank data are utilized to compare 452 community banks which failed between 2000 and 2013, relative to a sample of surviving community banks. Empirical results indicate that smaller banks are less likely to fail than their larger community bank counterparts. Additionally, several unique bank-specific indicators of failure emerge which relate to asset quality and liquidity, as well as earnings ratios. Moreover, results show that the use of the macroeconomic indicator of liquidity, the TED spread, provides a substantial improvement in modeling predictive community bank failure.

La mise à l'échelle de la technologie CMOS classique augmente les performances des circuits numériques grâce à la possibilité d'incorporation de composants de circuit supplémentaires dans la même zone de silicium. La technologie FDSOI 28nm de ST Microélectroniques est une stratégie d'échelle innovante qui maintient une structure de transistor planaire et donc une meilleure performance sans augmentation des coûts de fabrication de puces pour les applications basse tension. Il est important de s'assurer que l'augmentation des fonctionnalités et des performances ne se fasse pas au détriment de la fiabilité réduite, ce qui est assuré en répondant aux exigences des normes internationales ISO26262 pour les applications critiques dans les environnements automobile et industriel. Les entreprises de semi-conducteurs, pour se conformer à ces normes, doivent donc présenter des capacités d'estimation de la fiabilité au stade de la conception du circuit, qui est pour l'instant évaluer qu'après la fabrication d'un circuit numérique. Ce travail se concentre sur le vieillissement des standard cell et des circuits numériques avec le temps sous l'influence du mécanisme de dégradation du NBTI pour une large gamme de variations de processus, de tension et de température (PVT) et la compensation de vieillissement avec l'application de la tension à la face arrière (Body-Bias). L'un des principaux objectifs de cette thèse est la mise en place d'une infrastructure d'analyse de fiabilité composée d'outils logiciels et d'un modèle de vieillissement dans un cadre industriel d'estimation du taux de défaillance des circuits numériques au stade de la conception des circuits développés en technologie ST 28nm FDSOI
Scaling of classical CMOS technology provides an increase in performance of digital circuits owing to the possibility of incorporation of additional circuit components within the same silicon area. 28nm FDSOI technology from ST Microelectronics is an innovative scaling strategy maintaining a planar transistor structure and thus provide better performance with no increase in silicon chip fabrication costs for low power applications. It is important to ensure that the increased functionality and performance is not at the expense of decreased reliability, which can be ensured by meeting the requirements of international standards like ISO26262 for critical applications in the automotive and industrial settings. Semiconductor companies, to conform to these standards, are thus required to exhibit the capabilities for reliability estimation at the design conception stage most of which, currently, is done only after a digital circuit has been taped out. This work concentrates on Aging of standard cells and digital circuits with time under the influence of NBTI degradation mechanism for a wide range of Process, Voltage and Temperature (PVT) variations and aging compensation using backbiasing. One of the principal aims of this thesis is the establishment of a reliability analysis infrastructure consisting of software tools and gate level aging model in an industrial framework for failure rate estimation of digital circuits at the design conception stage for circuits developed using ST 28nm FDSOI technology

Ces dernières années ont vu l'émergence de nouveaux composants micro-ondes, les micro-commutateurs MEMS RF, possédant des performances très attrayantes pour de nombreux domaines d'application : spatial, automobile, téléphonie mobile& Cependant, une problématique majeure retarde actuellement leur industrialisation : leur fiabilité. Ce manuscrit de thèse a pour but principal de mettre en place les procédures d'investigation de la fiabilité des MEMS RF comprenant le développement des outils matériels et méthodologiques permettant d'analyser et de modéliser les phénomènes régissant la fiabilité de ces composants. Le premier chapitre effectue un état de l'art critique des bancs de tests et des résultats publiés par les laboratoires internationaux travaillant sur la fiabilité des MEMS RF. Le second chapitre détaille le banc de fiabilité développé dans le cadre de nos travaux. Nous présentons les différentes parties le constituant ainsi que les mesures des propriétés des MEMS RF qu'elles permettent d'effectuer en vue d'analyser leur fiabilité. Le troisième chapitre se focalise sur la méthodologie mise en place en vue d'étudier la fiabilité des micro-commutateurs capacitifs. Cette méthodologie est basée sur la détection et l'analyse des modes de défaillance d'une part et sur la modélisation du mécanisme de défaillance d'autre part. Nous proposons ainsi un modèle du chargement du diélectrique, principale cause de défaillance de ce type de composants, et introduisons un facteur de mérite de la fiabilité des MEMS RF permettant une évaluation comparative de leur durée de vie. Dans un quatrième chapitre, nous présentons les trois axes de recherche sur lesquels des études préliminaires ont été effectuées en vue d'améliorer la fiabilité des MEMS RF capacitifs : l'optimisation technologique, l'optimisation de la commande et l'optimisation de la topologie des micro-commutateurs

Defence date: 15 October 2007
Examining board: Prof. Giancarlo Corsetti, EUI, Supervisor ; Prof. Bernardo Guimaraes, London School of Economics ; Prof. Karl Schlag, EUI and Universitat Pompeu Fabra ; Prof. Eric Van Damme, Tilburg University
no abstract available

碩士
國立臺灣大學
經濟學研究所
96
The purpose of this research is to analysis the early warning of bank failure models using bank financial indicators and discuss the hazard function of healthy and default banks in Taiwan from 2002 to 2007, the year 2001 is a benchmark year. Factor analysis using Principal components method, and rotating the factor-loading matrix by the varimax method, this research shows that a bank will fail is a function of variables related to six financial indicators, including banking operations , assets quality, bank scale, capital adequacy, liquidity and growing. Empirical results show that the parametric model is superior to the semi-parametric model and the non-parametric model, as the majority of the regressors in the accelerated failure-time model are significant with the correct sign. Overall, the Log-logistic Model is advanced to indicate how the financial indicators can lead to the failure of the banks, and demonstrate good accuracy.

碩士
國立臺灣大學
財務金融學研究所
89
Bad loans in Taiwan have now risen to record highs─more than 6% of the total, but two or three times that level according to some analysts. The trend of increasing Non-Performing Loan (NPL) ratio is obvious and it seems that it will continue to increase. Many fear that there will be a full-fledged banking crisis. In this thesis, we used the most recent data and two kinds of models, the Option Pricing Model (OPM) and the Bank Failure Prediction Model (BFPM), to examine the quality of banks in this new economy. Among the OPMs, we used the Marcus-Shaked and Ronn-Verma models. In our results of the MS model, the premium rates (d) calculated from all data were a little small. The average premium rates were 1.46 at Jun. 2000, 0.21 at Dec. 1999, 0.47 at Jun. 1999, and 0.12 at Dec. 1998. At Jun. 2000, the DI of the number ranked bank was only 0.00045 while that of bank ranked last was 19.9 , far higher than that of the number one bank. It shows that though the average d lies within a reasonable range, the discrepancy of these rates is still high. Our results with the RV model show a much higher than normal level, indeed, some of the rates were even negative. Compared with the RV model, the MS model is relatively reliable. Though the results of either the MS model or the RV model are not such practical, we find an interesting phenomenon that the MS ranking had a very high correlation with each bank’s se. The correlation coefficient of ranking and se were higher than 90%. This is almost the same as Marcus and Shaked’s (1984) results though they used American banks as samples. In the BFPM, we used the Probit model, though we couldn’t find any apparent relationship between the OPM and the BFPM. The OPM’s most important contribution was se . If we take important financial variables and se into consideration, the result of BFPM is still reliable.

The present Dissertation addresses the early identification of U.S. commercial banks which eventually failed, and the choice of financial ratios that better capture the difference in performance, between them and solvent banks, after the 2007-2009 crisis. The sample comprises 69 failed banks between 2011 and 2012, each matched with a non-failed bank according to total deposits, charter class, number of branches and state (N=138). Two methodologies, in the form of four models, are adequately employed. Firstly, two logistic regressions, to predict the posterior odds of a bank’s failure, conditional on a set of financial ratios – one predicting bankruptcy in the upcoming year and another two years after (t-1 and t-2 models, respectively). Secondly, two linear discriminant analysis are estimated, to distinguish which ratios explain the difference in performance – again, for t-1 and t-2. Both t-1 models predicted which banks were going to fail next year, and which weren’t, with 97.83% of accuracy, while the t-2 models predicted approximately 90%, proving that failures are likely to be forecasted two years in advance. Besides the two loan quality variables present in all four models, the key variable to predict bank failures in t-1 is non-interest expense over operating income, and in t-2, the capital adequacy ratio. As a robustness check, out-of-sample testing was performed on 35 failed banks between 2013 and 2017, each matched with a non-failed bank (N=70). The results are fully validated and very stable, as the t-1 and t-2 models present, correct classifications of, approximately, 98% and 91%, respectively.
A presente Dissertação aborda a prévia identificação da falência de bancos comerciais norte-americanos e dos rácios financeiros que melhor captam a diferença de desempenho entre bancos falidos e bancos saudáveis, após a crise de 2007-2009. A amostra é constituída por 69 bancos falidos entre 2011 e 2012, cada um emparelhado com um banco saudável, de acordo com o total de depósitos, charter class, número de agências e estado (N=138). Aplicam-se duas metodologias, correspondentes a quatro modelos. Primeiramente, estimam-se duas regressões logísticas, que prevêem as probabilidades a posteriori de um banco falir, condicional a um conjunto de rácios financeiros - uma que prevê falência no próximo ano e outra que prevê dois anos depois (modelos t-1 e t-2, respetivamente). Seguidamente, duas análises discriminantes lineares são estimadas, para distinguir que rácios explicam a diferença de desempenho – novamente para os dois anos. Os modelos t-1 reclassificam a amostra com uma precisão de 97,83% e os t-2 de, aproximadamente, 90%, provando que é possível prever falências até dois anos antes. Além das duas variáveis relacionadas com qualidade de empréstimos presentes nos quatro modelos, a variável chave para prever falências em t-1 é a despesa sem juros sobre receitas operacionais e, em t-2, o rácio de adequação de capital. Testes de robustez, fora da amostra, foram realizados em 35 bancos falidos entre 2013 e 2017, cada um emparelhado com um banco saudável (N=70). Os resultados são validados e estáveis, visto que os modelos t-1 e t-2 apresentam, aproximadamente, classificações corretas de 98% e 91%, respetivamente.

碩士
國立高雄第一科技大學
金融營運所
92
We first studied the relationship between lending bank’s stock return and borrowing firms’ financial distress announcement. Then we buiet a financial crisis prediction model based on the credit scoring system, and finally, applied our prediction model to recent financial distress cases to see the forecasting power of our model. Empirical results show that: lending bank experienced negative abnormal return during borrowing firm’s financial distress period. The most influent factors are managerial ability, firm’s activity, and capital structure via matter factor analysis, logistic analysis and discriminant analysis is used. Using net worth ratio, operating profit per capital ratio and asset turnover ratio as factor to forecast the occurence of financial distress, we found that, discriminant analysis outperformed others.

Tese de Doutoramento em Economia
A crise global de 2008 e a crise europeia da dívida soberana que se lhe seguiu originaram, entre outras consequências, uma desconfiança generalizada nas instituições financeiras. Esta situação incita ao debate relativamente ao papel dos bancos cooperativos numa sociedade que se quer mais justa e à sua responsabilidade social, enquanto agentes chave para a recuperação económica, especialmente, nos países do sul da Europa. O sector bancário cooperativo permanece pouco compreendido e os desafios que se colocam à sua governação permanecem largamente inexplorados. A pesquisa incluída nesta tese visa aprofundar os conhecimentos sobre a conduta e desempenho dos bancos cooperativos e as suas descobertas apoiar o processo de tomada de decisão de membros e gestores, principalmente, em termos de governação. Assim, o principal objectivo deste estudo é analisar, em termos teóricos e empíricos, a governação e robustez financeira dos bancos cooperativos, tendo como referência as Caixas de Crédito Agrícola Mútuo (CCAM) e o seu sistema integrado (SICAM). Especificamente, a tese está estruturada de modo a responder às seguintes questões: (1) Quais as bases económicas dos bancos cooperativos?; (2) De que forma o seu enquadramento legal afecta a actividade da banca cooperativa?; (3) Qual o impacto dos diferentes mecanismos de governação dos bancos cooperativos no controlo da gestão?; e, por fim, (4) Quais os factores explicativos da falência dos bancos cooperativos portugueses? Além da Introdução (Capítulo 1) e das Conclusões (Capitulo 6), a resposta a estas quatro questões é formulada nos capítulos 2 a 5. O Capitulo 2 inclui uma resenha sobre a natureza económica das cooperativas enquanto organização económica específica, salientando as forças e fraquezas do modelo de governação da banca cooperativa. O Capitulo 3 apresenta uma revisão da regulamentação e alguns dados históricos sobre o sector da banca cooperativa em Portugal. O Capitulo 4 debruça-se sobre a governação dos bancos cooperativos, tomando especial atenção aos mecanismos de controlo que operam dentro do SICAM e avaliando os seus efeitos sobre a performance das CCAM através de dois modelos multinominal logit. O Capitulo 5 examina a sobrevivência das CCAM associadas do SICAM, analisando os determinantes do desaparecimento das CCAM, através de um modelo de regressão logística e outro de análise discriminante múltipla. Em termos empíricos, o período sob análise é, predominantemente, 1995-2009. Como reconhecido na literatura sobre o tópico, o modelo de governação cooperativa apresenta deficiências no controlo dos conflitos de agência, particularmente devido à sua natureza cooperativa, podendo mesmo por em causa a sua sobrevivência. Funcionando em rede, as CCAM foram capazes de melhorar a eficácia dos seus mecanismos de governação e, consequentemente, a sua performance. Os resultados salientam a importância do papel de supervisão da Caixa Central na performance das suas associadas. A análise da insolvência das CCAM enfatiza a importância da diversificação das suas fontes de rendimento e melhoria da eficiência custo, justificando assim o lobbying desenvolvido pelas CCAM no sentido da remoção das restrições à sua oferta de produtos, para melhor competir com os restantes bancos numa altura em que estes estão a reorientar as suas actividades para a banca tradicional, ou seja, para a banca a retalho doméstica, o negócio central das CCAM.
The 2008 global crisis, and the European sovereign debt crisis that follow it, originated, among other consequences, a general mistrust in financial institutions. This situation encourages the debate on the role of co-operative banks within a fairer society and their social responsibility as a key in the economic recovery, namely in the south European countries. The co-operative banking sector remains poorly understood and its specific governance challenges remain largely unexplored. The research included in this thesis aims to improve knowledge of the conduct and performance of the co-operative banks, and its findings should support the decision making process by members and management, mainly in terms of governance model. Thus, the main objective of this research is to analyse, both theoretically and empirically, the governance and financial robustness of co-operative banks, taking as a reference the Portuguese agricultural credit co-operatives (CCAM) and their integrated system(SICAM). Specifically, the thesis is structured in order to answer the following questions: (1)What are the economic bases of co-operative banks?; (2) How does a particular regulatory framework affect co-operative banking activity?; (3) What is the impact of the different governance mechanisms of co-operative banks on control management?; and (4) What are the explanatory factors of Portuguese co-operative bank failures? Besides the Introduction (Chapter 1) and the Conclusions (Chapter 6), the answer to these four questions is formulated in the chapters 2 to 5. Chapter 2 includes a survey of the economic nature of the co-operatives as a specific economic organisation, highlighting the strengths and the weaknesses of the governance model of co-operative banking. Chapter 3 presents a literature review of the regulatory framework and some historic data on the Portuguese cooperative credit system. Chapter 4 is concerned with the governance of co-operative banks, paying special attention to the control mechanisms operating within SICAM and assessing its effect on CCAM performance by two multinomial logit models. Chapter 5 is concerned with the survival of CCAM associated within SICAM, analysing the determinants of CCAM failures, by the estimation of a logistic regression analysis and a multiple discriminant analysis. In empirical terms, the period under analysis is mainly 1995–2009. As recognized in the literature on the topic, the co-operative governance model presents deficiencies in controlling agency conflicts, mainly resulting from its co-operative nature, which can jeopardize its survival. Operating in network, the CCAM are able to improve the effectiveness of CCAM governance mechanisms and, consequently, their performance. The results highlight the importance of the supervision role of Central CCAM in the performance of its associates. Moreover, the analysis of CCAM failure emphasizes the importance of diversifying CCAM income sources and of improving cost efficiency. This result support CCAM lobbying for the removal of product restrictions, in order to achieve better conditions to compete with IOF banks, at a time when these banks are reorienting their activities towards traditional banking activity, i.e., domestic retail banking, the usual business core of CCAM.

碩士
國立臺北大學
國際財務金融碩士在職專班
97
Since the financial system were opened to establish new banks,Taiwan’s banks have faced fierce competition . Finance’s crisis of some enterprises inflicted heavy loss on banks even caused the local financial storm. Therefore, our financial institution should set up a effective system of financial examination and prediction to avoid bankruptcy of bank and react to the problem early. This study collects the financial data of the 70 listed electronic companies ,210 terms including the samples of crisis state and normal state. In constructing the model, there are two main categories indicator, including financial ratio category and corporate governance category. Logit Regression model and Discriminated Analysis model are used in this study to establish precautionary finance-warning model . The methodology, first used average value of t-test to test whether crisis and normal companies are different. Then, used stepwise regression and stepwise discriminated analysis to find the important variables . Next, use the Logit Analysis, Discriminated Analysis, Quadratic Discriminated Analysis to make an analysis of all the samples. Furthermore we used the hit-ratio to verify the explanatory power of this model. Finally, we used the Logit Analysis, Quadratic Discriminated Analysis to get hit-ratio and have achieved three conclusions： 1. The results of t-test indicate that financial healthy company is higher than distress one for all ratio except debt ratio in financial ratio category . In corporate governance category the ratio of holding shares for directors , financial distress is higher than financial healthy company. 2. The empirical results indicate that the main influence factors extracted in financial index are ‘Earnings Per Share (EPS) ’”‘Equity Quick Ratio’, ‘”Directors who hold share”’, ‘Cash flow Ratio”. 3. The empirical results indicate that : (1) Test for the whole samples, the Logit Analysis, the Discriminated Analysis and Quadratic Discriminated Analysis got an accuracy is 86.67%、82.86%、91.43% , it shows Quadratic Discriminated Analysis has a better forecast ability. （2） Test by year, the Logit Analysis achieves an accuracy is 78.57%、82.86%、85.71% , and the Quadratic Discriminated Analysis achieves an accuracy is 97.14%、98.57%、98.57% . The forecast ability of Quadratic Discriminated Analysis model is suitable for bank loan-application model .

碩士
國立中央大學
化學工程與材料工程學系
101
Due to the number of the I/O (input/outout) counts in the advanced IC will continue to increase quickly; the diameter of flip-chip bumps will approach to 50 μm and below. The current density in each flip-chip bumps could reach 104 Amp/cm2 or higher. While the high density of current flowing through the flip-chip solder bumps, EM (electromigration)-induced failure has become a serious reliability issues for the solder joint. Hence, in this work, we will first propose a innovated concept of Sn back-filled phenomenon, and we will use this Sn back-filled flux (JSn,back-filled). Also, a new method of calculating Z* value of Cu in Cu6Sn5 has been proposed in Chapter 3. In Chapter 4, the entire EM-induced failure modes at the cathode Cu/Sn solder joint interface would be discussed in a great detail. In Chapter 4, we will introduce how to calculate the Sn back-filled flux (JSn,back-filled), and the Sn EM flux (JSn,EM). By knowing this two Sn back-filled flux (JSn,back-filled) and the Sn EM flux (JSn,EM), we can modify the failure map constructed by Hua Wei. By equaling the JSn,back-filled and the JSn,EM, we can obtain the a critical temperature (Tcrit.) at a constant current density. Then, we can use various critical temperatures to plot a EM-induced failure map at the cathode Cu/Sn interface under EM effect. Finally, based on the concept of Sn back-filled flux and Sn EM flux, we can construct a more reliable and accurate plot of the EM failure behavior at the cathode Cu/Sn interface.

碩士
中華大學
科技管理學系
106
As the expenditure of national defense has been cut and military organizational adjustment, the maintenance manpower has been reduced. Therefore, the planning of logistics support and resources will be more important. Especially the limitation of national defense funds, if there were a set of fault prediction systems that can be built for the maintenance and management of costly components, the probability of unintended failures of the system can be reduced, and maintenance or proper can be enhanced before risk response. Measures can also be used to stockpile the necessary spare parts in order to reduce the assets required for aircraft maintenance. The research is based on the objective of the Army's on-board target to obtain the system's daytime sensors. Firstly, to interview with experts to have 16 possible impact factors. Secondly, to learn the importance of the impact factors, and to screen the seven key factors which including affecting failure time of assembly, namely, the installed hours, Optical camera assembly, image encryption processor, cooling fan module assembly, signal noise processor, mechanical control torque motor, video signal processor function status (obtained by the instrument measurement ohms representative function) by Delphi questionnaire used Likert's fifth grade method. Finally, using the test data of National Army Helicopter Maintenance Unit from 2013 to 2017, the Alyuda Neuro Intelligence software was built to predict the failure time of the daytime sensor assembly. The verification results show that the model can be applied to the average fault time interval forecast of the assembly. In addition to this, it provides repair units with timely replacement of the timing of the incoming plant, the effective management and control of man-hours for the use of maintains, also be included in the unit assignments the risk of mission failure, and the provision of accurate supplements in advance which to increase the effective usage of equipment, and effectively save the cost of inventory, to maximize benefit of a limited defense budget.

abstract: Polymer matrix composites (PMCs) are attractive structural materials due to their high stiffness to low weight ratio. However, unidirectional PMCs have low shear strength and failure can occur along kink bands that develop on compression due to plastic microbuckling that carry strains large enough to induce nonlinear matrix deformation. Reviewing the literature, a large fraction of the existing work is for uniaxial compression, and the effects of stress gradients, such as those present during bending, have not been as well explored, and these effects are bound to make difference in terms of kink band nucleation and growth. Furthermore, reports on experimental measurements of strain fields leading to and developing inside these bands in the presence of stress gradients are also scarce and need to be addressed to gain a full understanding of their behavior when UDCs are used under bending and other spatially complex stress states. In a light to bridge the aforementioned gaps, the primary focus of this work is to understand mechanisms for kink band evolution under an influence of stress-gradients induced during bending. Digital image correlation (DIC) is used to measure strains inside and around the kink bands during 3-point bending of samples with 0°/90° stacking made of Ultra-High Molecular Weight Polyethylene Fibers. Measurements indicate bands nucleate at the compression side and propagate into the sample carrying a mixture of large shear and normal strains (~33%), while also decreasing its bending stiffness. Failure was produced by a combination of plastic microbuckling and axial splitting. The microstructure of the kink bands was studied and used in a microstructurally explicit finite element model (FEM) to analyze stresses and strains at ply level in the samples during kink band evolution, using cohesive zone elements to represent the interfaces between plies. Cohesive element properties were deduced by a combination of delamination, fracture and three-point bending tests used to calibrate the FEMs. Modeling results show that the band morphology is sensitive to the shear and opening properties of the interfaces between the plies.
Dissertation/Thesis
Doctoral Dissertation Mechanical Engineering 2016

Market frictions or market imperfections are diverse, broadly present in most markets, and affect most transactions in the economy. These market failures may prevent buyers and sellers from trading, even if they agree on a price. This means that the central assumption of perfectly competitive markets that markets clear fails to hold, and some buyers and sellers remain unmatched. Since the 1970s, a growing literature has emerged addressing the importance of market frictions in most markets of the economy, namely in the labor, product, and credit markets. Information asymmetries, transaction costs, heterogeneous preferences, and coordination failure are examples of sources of market imperfections. In labor markets, these frictions imply that firms possess some market power over their employees and that a one cent wage cut does not lead all workers to leave the firm. In product markets, a key ingredient for the sluggish price adjustment is coordination failure among firms. Firms respond incompletely to an aggregate shock because other firms have not yet responded. In turn, asymmetric information and costly contract enforcement provide the foundations of credit market frictions, and are used to explain credit rationing as a market equilibrium. In Chapter 1 we use matched employer-employee data and firm balance sheet data to investigate the importance of firm productivity and firm labor market power in explaining firm heterogeneity in wage formation. We use a linear regression model with one interacted high dimensional fixed effect to estimate 5-digit sector-specifc elasticity of output with respect to input factors directly from the production function. This allows us to derive firm specific price-cost mark-up and elasticity of labor supply. The results show that firms possess a considerable degree of product and labor market power. Furthermore, we find evidence that a firm's monopsony power negatively affects the earnings of its workers, and firm's total factor productivity is closely associated with higher earnings, ceteris paribus. We also find that firms use monopsony power for wage differentiation between male and female workers. Chapter 2 describes price setting behavior using a very rich dataset of producer prices collected for Portuguese frms. The Industrial Producer Prices Index dataset is comprised of monthly transaction prices collected for products defuned at a detailed level. We proceed with the analysis in two steps. First, we estimate a hazard function model for the probability of a price change with high dimensional fixed effects to extensively account for product and firm-specific time-invariant heterogeneity, splitting price changes between price decreases and price increases. Second, we estimate a peer-effects model to document how market competition affects firms' price setting rules. The results suggest that the likelihood of price adjustment depends on both idiosyncratic and sectoral conditions. Furthermore, when we fully account for heterogeneity, duration dependence is estimated to be positive in the case of both a price increase and price decrease. The results of the peer-effects model suggest that firms timidly respond to their competitors' price setting behavior. Chapter 3 examines the importance of credit demand and credit supply-related factors in explaining the evolution of credit granted to Portuguese small and medium-sized enterprises (SMEs). The results suggest that the interest rate is a strong driver of SMEs' demand for bank loans, as well as their internal financing capacity. On the other hand, credit supply mostly depends on firms' ability to generate cash-flows and reimburse their debt, and on the amount of collateral. The model was estimated for the period between 2010 and 2012. The results suggest that a considerable fraction of Portuguese SMEs were affected by credit rationing in this period.