TWO ESSAYS ON CORPORATE FINANCE

This dissertation consists of two essays on corporate finance. The first essay investigates the relationship between dual-class shares and firm’s risk-taking. While costs associated with dual-class shares are widely documented, the benefits are seldom studied in the literature. We attempt to fill this gap and find that dual-class firms tend to have fewer business segments, higher volatilities in their cash flows, earnings, and investment opportunities compared to propensity-matched single-class firms. Business segments within a dual-class firm are also more positively correlated in their cash flows, earnings, or investment opportunities than those in single-class firms. The results are consistent with the hypothesis that dual-class shares can potentially shield insiders from short-term market pressure so they can focus on riskier projects to enhance long-term shareholder value. To provide a possible channel through which dual-class firms can increase corporate risk-taking, we examine one of the most important corporate investment decisions: mergers and acquisitions (M&As). Dual-class firms are more likely to engage in M&As, especially nondiversifying M&As. Corporate risks increase following M&As, and the increase is more for dual-class firms than for single-class firms. The second essay shows how CEO skills affect operating performance using a sample of 109 spin-offs from 1994 to 2009. Since a variety of studies indicate that firms in need of external financing are more likely to engage in spin-offs, we hypothesize that parent firms prefer to appoint financial experts as CEOs at spun-off units around spin-off transactions. We find that appointing spun-off unit CEOs with financial expertise brings significant and positive wealth effects. Furthermore, the CEOs with financial expertise significantly improve firms’ access to capital markets and subsequent operating performance. Conversely, we do not observe positive wealth effects at the spin-off announcement or improved operating performance following spin-offs when parent firms decide to assign non-financial experts as spun-off unit CEOs

Transplanting assembly of individual carbon nanotubes

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.Includes bibliographical references (leaves 185-192).Handling and assembling individual nanostructures to bigger scale systems such as MEMS have been the biggest challenge. A deterministic assembly of individual carbon nanotubes by transplanting them to MEMS structures is demonstrated with a new assembly method, "transplanting assembly." This thesis describes development of a novel assembly technique by transforming individual CNTs assemblable, which enables manual, parallel or automated assembly of individual CNTs in a deterministic way. The key idea of transplanting assembly is to grow individual CNT strands on a substrate at optimal growth conditions, to encapsulate individual CNTs into micro-scale carrier blocks and to transplant them to the target locations. This new assembly method enables products such as CNT-tipped AFM probes in a predictable and repeatable manner. The major research topics discussed in this thesis are: (1) the methods to grow vertically aligned single strand CNTs at predefined locations, (2) the encapsulation method to preserve/control the orientation/exposed length of an individual CNT during transplanting, and (3) the assembly scheme to locate/release an individual CNT at the target location. An array of CNTs was grown from the nickel nano-dots, which were defined on Si substrates using electron-beam lithography followed by metal deposition and lift-off processes. Each CNT strand was embedded into a MEMS scale polymer block which serves as a CNT carrier. A double polymeric layer encapsulation was designed and implemented: the top SU-8 forms the body of the carrier while the bottom PMGI layer holds the body until the release of the carrier from the substrate and then is going to be removed to expose the CNT tip with a predefined length. A model was developed to predict mechanical behavior of individual CNTs under the flow of liquid polymers. Manual assembly of a polymer block to the end of a tipless AFM cantilever forms a CNT-tipped AFM probe, which can be accomplished in minutes without laborious weeding, trimming and welding process. The AFM scanning results confirmed the CNTtipped AFM probe's much improved imaging performance and potential for scanning soft biological samples at nanometer resolutions.by Soohyimg Kim.Ph.D

Transmembrane Helix Assembly by Window Exchange Umbrella Sampling

A method of window exchange umbrella sampling molecular dynamics simulation is employed for transmembrane helix assembly. An analytical expression for the average acceptance probability between neighboring windows is derived and combined with the first passage time optimization method to predetermine a parameter set in an optimal range. With the parameter set, the method provides a substantially more efficient sampling of helix-helix interfaces together with the potential of mean force along the helix-helix distance of a transmembrane helix-dimer model, compared to the umbrella sampling method

Axion dark matter search using the storage ring EDM method

We propose using the storage ring EDM method to search for the axion dark matter induced EDM oscillation in nucleons. The method uses a combination of B and E-fields to produce a resonance between the $g-2$ spin precession frequency and the background axion field oscillation to greatly enhance sensitivity to it. An axion frequency range from $10^{-9}$ Hz to 100 MHz can in principle be scanned with high sensitivity, corresponding to an $f_a$ range of $10^{13}$ GeV $\leq f_a \leq 10^{30}$ GeV, the breakdown scale of the global symmetry generating the axion or axion like particles (ALPs)

DETC2004-57606 A FRAMEWORK AND DESIGN SYNTHESIS TOOL USED TO GENERATE, EVALUATE AND OPTIMIZE COMPLIANT MECHANISM CONCEPTS FOR RESEARCH AND EDUCATION ACTIVITES

ABSTRACT In 2002, a Microsoft-MIT iCampus effort was initiated to generate methods and tools which accelerate the process by which students and researchers acquire perspective and skill in compliant mechanism design: (1) Experience and skill: A synthesis tool, CoMeT, was developed as a means for researchers and students to gain experience and skill in working with old (education) and new (research) compliant mechanisms. The simulator is based on compliance theory and screw theory. (2) Perspective: A framework, the 5 Fs, was developed to help designers form a holistic perspective on compliant mechanisms. A "big picture" view helps them systematically identify and link the important elements of a compliant mechanism problem. This opens to door for them to properly conceptualize, model and fabricate these mechanisms. In this paper we discuss the work of early compliant mechanism/instrument designers to gain insight into how they thought about, designed and taught others about compliant mechanisms. We explain how their work has influenced the development of our framework and simulator. We then show results obtained by using the framework and simulator at MIT in: (1) Compliant mechanism research: Generation of a compliant mechanism for an R&D 100 award winning, six-axis Nanomanipulator. (2) Compliant mechanism education: Use within student projects to design two devices: A compliant x-y Nanomanipulator with 30x30 µm range and a MEMS accelerometer. Both devices are designed, fabricated and tested in a semester-long class

Propose with a Rose? Signaling in Internet Dating Markets

The large literature on costly signaling and the somewhat scant literature on preference signaling had varying success in showing the effectiveness of signals. We use a field experiment to show that even when everyone can send a signal, signals are free and the only costs are opportunity costs, sending a signal increases the chances of success. In an online dating experiment, participants can attach “virtual roses” to a proposal to signal special interest in another participant. We find that attaching a rose to an offer substantially increases the chance of acceptance. This effect is driven by an increase in the acceptance rate when the offer is made to a participant who is less desirable than the proposer. Furthermore, participants endowed with more roses have more of their offers accepted than their counterparts.

Reduction of coherent betatron oscillations in a muon g-2 storage ring experiment using RF fields

This work demonstrates that two systematic errors, coherent betatron oscillations (CBO) and muon losses can be reduced through application of radio frequency (RF) electric fields, which ultimately increases the sensitivity of the muon $g-2$ experiments. As the ensemble of polarized muons goes around a weak focusing storage ring, their spin precesses, and when they decay through the weak interaction, $\mu^+ \rightarrow e^+ \nu_e \bar{\nu_\mu}$, the decay positrons are detected by electromagnetic calorimeters. In addition to the expected exponential decay in the positron time spectrum, the weak decay asymmetry causes a modulation in the number of positrons in a selected energy range at the difference frequency between the spin and cyclotron frequencies, $\omega_\text{a}$. This frequency is directly proportional to the magnetic anomaly $a_\mu =(g-2)/2$, where $g$ is the g-factor of the muon, which is slightly greater than 2. The detector acceptance depends on the radial position of the muon decay, so the CBO of the muon bunch following injection into the storage ring modulate the measured muon signal with the frequency $\omega_\text{CBO}$. In addition, the muon populations at the edge of the beam hit the walls of the vacuum chamber before decaying, which also affects the signal. Thus, reduction of CBO and unwanted muon loss increases the $a_\mu$ measurement sensitivity. Numerical and experimental studies with RF electric fields yield more than a magnitude reduction of the CBO, with muon losses comparable to the conventional method.Comment: 14 pages, 25 figure