8,187 research outputs found
Real Options Models in Real Estate
Our aim in this thesis is to investigate the usefulness of real options analysis, taking case studies of problems in real estate. In the realm of real estate, we consider the following three problems. First, we consider the valuation and usefulness of presale contracts of condominiums, which can be viewed as similar to call options on condominiums. Secondly, we consider the valuation of farm land from the perspective of land developers, who may think of farm land as being similar to call options on subdivision lots. Third, we consider the valuation of opportunities to install solar panels on properties, in which properties may be considered call options on electricity generators. Through consultation with industry professionals, we created models with the aim of being as realistic as possible without losing analytical tractability. In all three problems, we assess the potential value added through the usage of real options modeling techniques over more traditional techniques, using realistic parameter regimes. We utilize a set of sophisticated mathematical and numerical tools to mathematically model problems. We find that for some problems, real options models only add minimal value to more traditional capital budgeting techniques such as the Net Present Value model. In other problems, we find that real options models lead to significantly different sets of conclusions from those predicted by more traditional techniques
Relaxation of superfluid turbulence in highly oblate Bose-Einstein condensates
We investigate thermal relaxation of superfluid turbulence in a highly oblate
Bose-Einstein condensate. We generate turbulent flow in the condensate by
sweeping the center region of the condensate with a repulsive optical
potential. The turbulent condensate shows a spatially disordered distribution
of quantized vortices and the vortex number of the condensate exhibits
nonexponential decay behavior which we attribute to the vortex pair
annihilation. The vortex-antivortex collisions in the condensate are identified
with crescent-shaped, coalesced vortex cores. We observe that the
nonexponential decay of the vortex number is quantitatively well described by a
rate equation consisting of one-body and two-body decay terms. In our
measurement, we find that the local two-body decay rate is closely proportional
to , where is the temperature and is the chemical potential.Comment: 7 pages, 9 figure
Observation of a Geometric Hall Effect in a Spinor Bose-Einstein Condensate with a Skyrmion Spin Texture
For a spin-carrying particle moving in a spatially varying magnetic field,
effective electromagnetic forces can arise due to the geometric phase
associated with adiabatic spin rotation of the particle. We report the
observation of a geometric Hall effect in a spinor Bose-Einstein condensate
with a skyrmion spin texture. Under translational oscillations of the spin
texture, the condensate resonantly develops a circular motion in a harmonic
trap, demonstrating the existence of an effective Lorentz force. When the
condensate circulates, quantized vortices are nucleated in the boundary region
of the condensate and the vortex number increases over 100 without significant
heating. We attribute the vortex nucleation to the shearing effect of the
effective Lorentz force from the inhomogeneous effective magnetic field.Comment: 9 pages, 11 figure
Temperature Dependent Current-voltage Characteristics of P-type Crystalline Silicon Solar Cells Fabricated Using Screen-printing Process
We have fabricated p-type crystalline silicon (Si) solar cells using screen-printing process and investigated their electrical properties. Ph screen printing process led to the uniform formation of n+ emitter. As a result of interaction between Ph-dopant paste and Si substrate, a phosphosilicate glass layer was formed on n+ emitter surface. The current-voltage characteristics were carried out in the temperature range of 175 – 450 K in steps of 25 K. The variation in current level at a particular voltage strongly depended on temperature, indicating that the current transport across the junction was a temperature activated process. The reverse leakage current gradually increased with increasing measurement temperature up to 350 K, above which it rapidly increased. Arrhenius plot of the leakage current revealed that reverse leakage current in low and high temperature regions were dominated by the tunneling mechanism, and generation and recombination mechanism, respectively. Keywords: P-type Si solar cell, screen-printing, I-V, tunneling, generation and recombination, reverse leakage curren
From Text to Sign Language: Exploiting the Spatial and Motioning Dimension
PACLIC 19 / Taipei, taiwan / December 1-3, 200
Estimation of axial curvature of anterior sclera: correlation between axial length and anterior scleral curvature as affected by angle kappa
Background: Though the development and fitting of scleral contact lenses are expanding steadily, there is no simple method to provide scleral metrics for scleral contact lens fitting yet. The aim of this study was to establish formulae for estimation of the axial radius of curvature (ARC) of the anterior sclera using ocular biometric parameters that can be easily obtained with conventional devices. Methods: A semi-automated stitching method and a computational analysis tool for calculating ARC were developed by using the ImageJ and MATLAB software. The ARC of all the ocular surface points were analyzed from the composite horizontal cross-sectional images of the right eyes of 24 volunteers; these measurements were obtained using anterior segment optical coherence tomography for a previous study (AS-OCT; Visante). Ocular biometric parameters were obtained from the same volunteers with slit-scanning topography and partial coherence interferometry. Correlation analysis was performed between the ARC at 8 mm to the axis line (ARC[8]) and other ocular parameters (including age). With ARC obtained on several nasal and temporal points (7.0, 7.5, 8.0, 8.5, and 9.0 mm from the axis line), univariate and multivariate linear regression analyses were performed to develop a model for estimating ARC with the help of ocular biometric parameters. Results: Axial length, spherical equivalent, and angle kappa showed correlations with temporal ARC[8] (tARC[8]; Pearson’s r = 0.653, −0.579, and −0.341; P = 0.001, 0.015, and 0.015, respectively). White-to-white corneal diameter (WTW) and anterior chamber depth (ACD) showed correlation with nasal ARC[8] (nARC[8]; Pearson’s r = −0.492 and −0.461; P = 0.015 and 0.023, respectively). The formulae for estimating scleral curvatures (tARC, nARC, and average ARC) were developed as a function of axial length, ACD, WTW, and distance from the axis line, with good determinant power (72 − 80 %; SPSS ver. 22.0). Angle kappa showed strong correlation with axial length (Pearson’s r = −0.813, P <0.001), and the different correlation patterns of nasal and temporal ARC with axial length can be explained by the ocular surface deviation represented by angle kappa. Conclusions: Axial length, ACD, and WTW are useful parameters for estimating the ARC of the anterior sclera, which is important for the haptic design of scleral contact lenses. Angle kappa affects the discrepancies between the nasal and temporal scleral curvature.Korea (South). Ministry of Health & Welfare (Projects A084496 and A120018
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