9,721 research outputs found

    How Law and Institutions Shape Financial Contracts: The Case of Bank Loans

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    We examine empirically how legal origin, creditor rights, property rights, legal formalism, and financial development affect the design of price and non-price terms of bank loans in almost 60 countries. Our results support the law and finance view that private contracts reflect differences in legal protection of creditors and the enforcement of contracts. Loans made to borrowers in countries where creditors can seize collateral in case of default are more likely to be secured, have longer maturity, and have lower interest rates. We also find evidence, however, that ?Coasian? bargaining can partially offset weak legal or institutional arrangements. For example, lenders mitigate risks associated with weak property rights and government corruption by securing loans with collateral and shortening maturity. Our results also suggest that the choice of loan ownership structure affects loan contract terms.

    Financing firms in India

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    The authors examine the legal and business environments, financing channels, and governance mechanisms of various types of firms in India and compare them to those from other countries. Despite its English commonlaw origin, strong legal protection provided by the law, and a democratic government, corruption within India's legal system and government significantly weakens investor protection in practice. External financing of firms has been dominated by nonmarket sources of financing, while the characteristics of listed firms are similar to those from countries with weak investor protection. The evidence, including results based on a survey of small and medium-scale private firms, shows that alternative financing channels provide the most important source of funds. The authors also find that informal governance mechanisms, such as those based on reputation, trust, and relationships are more important than formal mechanisms (such as courts) in resolving disputes, overcoming corruption, and supporting growth.Banks&Banking Reform,Corporate Law,Financial Intermediation,Governance Indicators,Small Scale Enterprise

    Modeling and Simulation of \Sub-Microsecond Electrical Breakdown in Liquids with Application to Water

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    In this dissertation, the inherent physics and sub-microsecond electrical breakdown of water stressed to high voltages is analyzed, and several relevant models are constructed for quantitative analysis. A bubble-based, drift-diffusion (DD) model proposed here includes almost all the important physical process of the system, and successfully explains many important features routinely observed in sub-microsecond water electrical breakdown. Here many physical properties and response characteristics typical for high-field stressing of liquid water have been analyzed through numerical calculations. The internal temperature profile in the water system has been calculated by Finite Difference Time Domain (FDTD) method to probe possible heating and vaporization effects. Results show temperature increases of less than 7° Kelvin, precluding possibilities for localized evaporation. Second, it is shown through Monte-Carlo simulations that electrons in liquid water cannot contribute to impact ionization and electron multiplication at normal liquid water densities. Instead, it is shown that electrons emitted within pre-existing microbubbles within the liquid could contribute to electron multiplication and initiate the electric breakdown process. Third, it is demonstrated here through microscopic Monte-Carlo calculations that the dielectric constant of water would be a monotonically decreasing function of the electrical field, with strong reductions beyond 3 MV/cm. It is also shown that this field-dependent behavior, coupled with electric field enhancements across dielectric discontinuities such as the water-bubble interface, can potentially contribute to electrical breakdown. Finally, the most important contribution of this dissertation is the development of a bubble-based, drift-diffusion (DD) model that includes the field-dependent effects. Simulation results based on this model show strong agreement with many features of experimentally observed features. The features include: (i) streamer branching for the positive polarity due to internal micro-bubbles; (ii) negative streamers normally having a higher breakdown voltage requirement; (iii) negative streamers having a thicker root and larger cross-sectional radii as compared to positive streamers; (iv) increasing hold-on voltage with system over-pressure; and (v) faster breakdown times for positive polarity, point-plane geometries. The model is quite general, and applicable to other liquids

    Energy Efficient Massive MIMO and Beamforming for 5G Communications

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    Massive multiple-input multiple-output (MIMO) has been a key technique in the next generation of wireless communications for its potential to achieve higher capacity and data rates. However, the exponential growth of data traffic has led to a significant increase in the power consumption and system complexity. Therefore, we propose and study wireless technologies to improve the trade-off between system performance and power consumption of wireless communications. This Thesis firstly proposes a strategy with partial channel state information (CSI) acquisition to reduce the power consumption and hardware complexity of massive MIMO base stations. In this context, the employment of partial CSI is proposed in correlated communication channels with user mobility. By exploiting both the spatial correlation and temporal correlation of the channel, our analytical results demonstrate significant gains in the energy efficiency of the massive MIMO base station. Moreover, relay-aided communications have experienced raising interest; especially, two-way relaying systems can improve spectral efficiency with short required operating time. Therefore, this Thesis focuses on an uncorrelated massive MIMO two-way relaying system and studies power scaling laws to investigate how the transmit powers can be scaled to improve the energy efficiency up to several times the energy efficiency without power scaling while approximately maintaining the system performance. In a similar line, large antenna arrays deployed at the space-constrained relay would give rise to the spatial correlation. For this reason, this Thesis presents an incomplete CSI scheme to evaluate the trade-off between the spatial correlation and system performance. In addition, the advantages of linear processing methods and the effects of channel aging are investigated to further improve the relay-aided system performance. Similarly, large antenna arrays are required in millimeter-wave communications to achieve narrow beams with higher power gain. This poses the problem that locating the best beam direction requires high power and complexity consumption. Therefore, this Thesis presents several low-complexity beam alignment methods with respect to the state-of-the-art to evaluate the trade-off between complexity and system performance. Overall, extensive analytical and numerical results show an improved performance and validate the effectiveness of the proposed techniques
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