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Because of the high cost and the irreversibility of the big investment company decision maker often choose to defer the investment until the uncertainty gets clear. That is a management flexibility to decrease the risky. This article analyze that when company faces two competing technology that one have competing advantage comparing with the other under an uncertainty situation how does the company decide when and which to adopt. We develop a continuous-time stochastic model that aids in determination of optimal timing for adoption within the framework of real options theory. We propose that the competing situation between two incompatible technologies follows the general Wiener Process. When company chose to defer the investment we use the expectations of the decision maker and the competing situation between two technologies to decide the optimal investment timing. The result of this thesis suggests that a technology adopter should defer its investment until one technology¡¦s probability to win out in the market place and achieve critical mass reaches a critical threshold. This research only provides a way to show the decision maker when and which to adopt but not guarantee that the technology being chose will dominate the market in the future.

a b s t r a c t A periodic steady state is a familiar phenomenon in many areas of theoretical biology and provides a satisfying explanation for those animal communities in which populations are observed to oscillate in a reproducible periodic manner. In this paper we explore models of three competing species described by symmetric and asymmetric May–Leonard models, and specifically investigate criteria for the existence of periodic steady states for an adapted May–Leonard model: x˙ = r(1 − x − ˛y − ˇz)x y˙ = (1 − ˇx − y − ˛z)y z˙ = (1 − ˛x − ˇy − z)z. Using the Routh–Hurwitz conditions, six inequalities that ensure the stability of the system are identified. These inequalities are solved simultaneously, using numerical methods in order to generate three-dimensional phase portraits to illustrate the steady states. Then the “stability boundary” is defined as the almost linear boundary between stability and instability. All the mathematics discussed is suitable for advanced undergraduate mathematics or applied mathematics students, offering them the opportunity to incorporate a computer algebra system such as Mathematica, DERIVE or Matlab in their investigations. The adapted May–Leonard model provides a practical application of steady states, stability and possible limit cycles of a nonlinear system.

Oral anticoagulants (OACs) are indicated in the first-line treatment of venous thromboembolism (VTE), which comprises of deep vein thrombosis (DVT) and pulmonary embolism (PE). While contemporary guidelines recommend extended-duration anticoagulation after the first diagnosis of unprovoked VTE, the benefits and harms associated with this approach remain unclear across age groups, especially among older adults. Crucially, contemporary estimates of VTE recurrence have not incorporated all-cause mortality as a competing event, the risk of which increases with age. Therefore, we evaluated and synthesized existing literature on of the risk of all-cause mortality by age following completion of limited-duration anticoagulation for a first episode of unprovoked VTE. In addition, we determined the risk of VTE recurrence after completion of limited-duration OAC therapy by age, with death as a competing outcome using data from a prospective cohort study.

published_or_final_version / Statistics and Actuarial Science / Doctoral / Doctor of Philosophy

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Thesis advisor: Hong Ding / Thesis advisor: Vidya Madhavan / High temperature superconductivity has been one of the most challenging problems in condensed matter physics since its discovery. This dissertation presents systematic studies on the single layer high temperature superconductor Bi2Sr2-xLaxCuO6+delta by scanning tunneling microscopy. The STM results have been compared to Angle-resolved photoemission spectroscopy (ARPES) data. Using STM spectroscopy and ARPES we observed two distinct gaps that coexist both in real space and in the antinodal region of momentum space, below the superconducting transition temperature. By looking at the energy scale of these two gaps along with the temperature dependence data, we fnd that the small gap is associated with superconductivity. The large gap persists above Tc, and seems linked to observed charge ordering. We also find a strong correlation between the large and small gaps suggesting that they are affected by similar physical processes. This is the first time that two coexisting and competing energy scales have been directly observed in STM spectroscopy. Combining this with ARPES data, we show that the pseudogap may be a diffferent order parameter from the superconducting phase. This provides support to the recently proposed "two gaps scenario" and should lead to more experimental discovery and theoretical discussions. In this dissertation we also discuss the spatial properties of the scanning tunneling microscopy conductance maps, as well as the charge ordering pattern at high energies. We observe interesting periodic patterns at low energies which can not be explained by a simple charge density wave picture. We also fnd the surprising bias dependence in terms of the contrast reversal. We propose a model of STM measuring effect to explain these phenomena. / Thesis (PhD) — Boston College, 2009. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Physics.

The middle period of the 20th century, the births of electronic calculator and information transmission technology, let the civilized development course be faster. Under the situation in the considerable and significant growth of product-producing and cultural dissemination , the compatibility of products is shaped into the top theme that sought together by customers and manufacturers .The growth of the diverse products in markets gives a chance of option to the users in markets .This research shows that it will only be after undergoing the marketable course of competition certainly when every manufacturer introduces the products , could determines that whether it's a market that monopolize or a situation that is formed by the incompatibility of every product from each manufacturer. Based this background, The research was done by using language Visual Basic to write a function about marketing share¡Buser preference ¡Btechnology and strategy to confer when ¡Bwhy and how the competing technologies will become Monopoly or have marketing shares with each other in a long period. From the conclusion of this research, we know what will the firms do under the supposition of this research and there is the description about the limit in this research and the feasibility study in the future.