Three essays on the role of knowledge as a driver of entry and industry dynamics

This dissertation addresses the question of how the knowledge characteristics of firms and industries affect firm entry. Firm entry is considered an important aspect of any analysis in industrial economics or management, due to its direct implications on market structure and competition. Knowledge, in particular, is found to be a prominent driver of firm entry, and is important in explaining the differences across entrants in various industries. Moreover, the identification of the mechanism behind the differences in entry patterns can greatly increase our understanding of how industries evolve in the long run. This requires, however, a thorough examination of the interplay between the knowledge of potential entrants and the knowledge in industries. All these themes are at the base of this dissertation, and are addressed across three chapters from different perspectives. The first chapter, titled “The technological regimes and barriers to entry”, focuses on how industries’ knowledge characteristics, described by their technological regimes, affect the entry of firms, each of which may react differently. The results show that there are significant interaction effects between the different elements of the technological regime. In addition, certain types of entrants seem be affected by the technological regime in significantly different ways, especially diversifiers that are innovative and are from related industries. The second chapter, titled “Where do firms come from? Knowledge relatedness and firm entry”, looks at how the individual potential entrants, which may be diversifiers, spinoffs, or spinouts, make their decision to enter an industry based on how related their knowledge is to the knowledge of the target industry. The results suggest that the relationship takes an inverted U shape for spinouts. For diversifiers and spinoffs, the relationship is U-shaped instead, suggesting that the two effects identified in the theoretical framework vary in strength depending on the types of entrants. The third chapter, titled “Who enters and when? Knowledge relatedness, entrant heterogeneity, and industry characteristics”, expands this perspective to include how the industry-level moderators may alter the relationship between knowledge relatedness and entry for different types of entrants. The results of this paper show that industry characteristics matter in moderating the relationship between knowledge relatedness and entry, but some are more relevant than others. Modularity and innovators concentration, in particular, seem to significantly affect the relationship. By looking at the question with these different perspectives, the studies in the dissertation show that knowledge characteristics of both firms and industries have major impacts on entry, and by extension on market structure

Charge density wave surface reconstruction in a van der Waals layered material

Surface reconstruction plays a vital role in determining the surface electronic structure and chemistry of semiconductors and metal oxides. However, it has been commonly believed that surface reconstruction does not occur in van der Waals layered materials, as they do not undergo significant bond breaking during surface formation. In this study, we present evidence that charge density wave (CDW) order in these materials can, in fact, cause CDW surface reconstruction through interlayer coupling. Using density functional theory calculations on the 1T-TaS2 surface, we reveal that CDW reconstruction, involving concerted small atomic displacements in the subsurface layer, results in a significant modification of the surface electronic structure, transforming it from a Mott insulator to a band insulator. This new form of surface reconstruction explains several previously unexplained observations on the 1T-TaS2 surface and has important implications for interpreting surface phenomena in CDW-ordered layered materials.Comment: 20 pages, 6 figures (Supplementary Information: 5 Pages, 3 figures

A study of the causal relationship between IT governance inhibitors and its success in Korea enterprises

노트 : Proceedings of the 41st Hawaii International Conference on System Sciences - 2008 행사명 : 41st Hawaii International Conference on System Sc

Stretching-induced conductance variations as fingerprints of contact configurations in single-molecule junctions

Molecule-electrode contact atomic structures are a critical factor that characterizes molecular devices, but their precise understanding and control still remain elusive. Based on combined first-principles calculations and single-molecule break junction experiments, we herein establish that the conductance of alkanedithiolate junctions can both increase and decrease with mechanical stretching and the specific trend is determined by the S-Au linkage coordination number (CN) or the molecule-electrode contact atomic structure. Specifically, we find that the mechanical pulling results in the conductance increase for the junctions based on S-Au CN two and CN three contacts, while the conductance is minimally affected by stretching for junctions with the CN one contact and decreases upon the formation of Au monoatomic chains. Detailed analysis unravels the mechanisms involving the competition between the stretching-induced upshift of the highest occupied molecular orbital-related states toward the Fermi level of electrodes and the deterioration of molecule-electrode electronic couplings in different contact CN cases. Moreover, we experimentally find a higher chance to observe the conductance enhancement mode under a faster elongation speed, which is explained by ab initio molecular dynamics simulations that reveal an important role of thermal fluctuations in aiding deformations of contacts into low-coordination configurations that include monoatomic Au chains. Pointing out the insufficiency in previous notions of associating peak values in conductance histograms with specific contact atomic structures, this work resolves the controversy on the origins of ubiquitous multiple conductance peaks in S-Au-based single-molecule junctions.Comment: 11 pages, 4 figures; to be published in J. Am. Chem. So