This dissertation studies the impact of business relations on firms' financing decisions. The goal is to understand the determinants of business relations and how they interact with firms' capital structure. In the first chapter, I present a model which studies the role of customer risk in suppliers' financing choice. The base model predicts that when faced with a high-risk customer, suppliers with significant continuation values prefer equity over debt. The extended model allows for analyzing the supplier's decision to concentrate on a single major customer or diversify into multiple customers. The model shows that by decreasing the risk of premature liquidation, diversification allows for the supplier to take advantage of the bargaining benefits of debt. The second chapter empirically investigates the impact of customer risk on suppliers' capital structure. Consistent with the model presented in the first chapter, both cross-sectional and time-series regression results show that customer risk has a negative impact on suppliers' debt financing. Customer risk is an important determinant of suppliers' method of financing as well. During the first two years of the relationship, suppliers with high-risk customers are more likely to raise equity. Comparing the impact of customer risk on different supplier groups shows that firms that operate in concentrated industries and younger firms are more sensitive to changes in customer risk. In further analyses I find that the risk is transferred from customers to suppliers: There is a lead-lag relationship between customer and supplier credit rating changes. Also, suppliers experience an increase in volatility of their stock returns after they start a new relationship with a risky customer. Results from further analyses are suggestive of customer risk affecting capital structure through its impact on supplier risk. / text

published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

Our understanding of the functions played by RNA molecules is expanded with the understanding of RNA structures. Except for primary structure, RNA molecules present pairings within a sequence, which is called RNA secondary structure. Since its discovery, RNA secondary structure has drawn considerable attention because it is widely appeared. Many programs for RNA secondary structure prediction have been developed, including [4, 20, 38, 39, 46]. Based on our knowledge, however, there is a family of RNA secondary structure which can not be covered by any of these algorithms. And even without considering this family, none of programs can cover all other structures in Rfam data-set. These structures are found to be important in many biological processes, for example, chromosome maintenance, RNA processing, protein biosynthesis. And efficient structure prediction can give direction for experimental investigations. Here, we present a general algorithm with a new grammar: Vertical Tree Grammar (VTG) which has stochastic context-free grammar architecture for RNA secondary structure prediction. VTG significantly expands the class of structures that can be handled, including all structures that can be covered by other paper, and all structures in Rfam data-set. Our algorithm runs in O(n^6) time, and it's precision is reasonable high, with average sensitivity and specificity over 70%. / published_or_final_version / Computer Science / Master / Master of Philosophy

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<p> This dissertation examines the embodied cultural practice of dance among several groups in the Kansas City area. The dance groups were studied as Communities of Practice (CoP), as outlined in the Lave-Wenger model of CoP. The CoP model uses the complementary concepts of &ldquo;reified structures&rdquo; and &ldquo;peripheral participation&rdquo; to explain social learning. This dissertation argues that participation in dance activities creates body schema and social bonds that make dance a powerful mechanism for learning and teaching social behaviors. The dance groups studied covered a spectrum of dance genres, including folkloric, popular, hip-hop, ballroom, ballet, and modern dance. Data were collected from participant observation, interviews, archives, cable TV shows, websites, and published materials. Archival documentation included photographic and video materials, as well as survey data available for secondary analysis. Grounded Theory Methodology based on qualitative data was deemed the most appropriate approach. By examining these dance groups, certain social processes were consistently observed, including 1) similarities in dance practice across groups led to similar social practices and processes over the lifespan; 2) differences in dance genre aesthetic structure were associated with different forms of CoP structure and organization; the more structured the aesthetic of the dance genre, the more structured and hierarchical the organization of the dance group; 3) certain factors/attributes of the CoPs contributed to the dance group&rsquo;s robustness and longevity; and 4) the mediation of time and space with other dancers during dance served as a model of interactions between self and others and developed the skills of collaboration. Overall, this study found the sharing and mediation of time and space during dance shaped individual social interactions into increasingly cooperative and collaborative activities. Also, the aesthetic structure of the dance genre was associated with the dance group's hierarchical social structure.</p>

Structure sense är ett begrepp som nyligen har börjat användas inom matematikdidaktik föratt beskriva elevers förståelse för matematiska strukturer. Syftet med det härexamensarbetet är att utforska begreppet structure sense genom att jämföra olikadefinitioner av begreppet. Vidare är syftet också att jämföra structure sense med tre andraliknande begrepp: symbol sense, personal structure och awareness of mathematical pattern and structure. Litteraturstudien bygger på 13 vetenskapliga publikationer som samlades in ochanalyserades. Samtliga publikationer är skrivna av internationella forskare. I resultatetpresenteras och jämförs structure sense utifrån fyra olika definitioner. De olikadefinitionerna av begreppet är riktade mot olika nivåer av matematik men gemensamt förbeskrivningarna är att structure sense uppfattas som en eller flera förmågor som innefattarett mångfacetterat sätt att uppfatta matematisk struktur.