43 research outputs found
A Computational Tool for Testing Dose-related Trend Using an Age-adjusted Bootstrap-based Poly-k Test
A computational tool for testing for a dose-related trend and/or a pairwise difference in the incidence of an occult tumor via an age-adjusted bootstrap-based poly-k test and the original poly-k test is presented in this paper. The poly-k test (Bailer and Portier 1988) is a survival-adjusted Cochran-Armitage test, which achieves robustness to effects of differential mortality across dose groups. The original poly-k test is asymptotically standard normal under the null hypothesis. However, the asymptotic normality is not valid if there is a deviation from the tumor onset distribution that is assumed in this test. Our age-adjusted bootstrap-based poly-k test assesses the significance of assumed asymptotic normal tests and investigates an empirical distribution of the original poly-k test statistic using an age-adjusted bootstrap method. A tumor of interest is an occult tumor for which the time to onset is not directly observable. Since most of the animal carcinogenicity studies are designed with a single terminal sacrifice, the present tool is applicable to rodent tumorigenicity assays that have a single terminal sacrifice. The present tool takes input information simply from a user screen and reports testing results back to the screen through a user-interface. The computational tool is implemented in C/C++ and is applied to analyze a real data set as an example. Our tool enables the FDA and the pharmaceutical industry to implement a statistical analysis of tumorigenicity data from animal bioassays via our age-adjusted bootstrap-based poly-k test and the original poly-k test which has been adopted by the National Toxicology Program as its standard statistical test
Analysis of the Fully Developed Chute Flow of Granular Materials
Existing constitutive relations and governing equations have been used to solve for fully developed chute flows of granular materials. In particular, the results of Lun et al. (1984) have been employed and the boundary value problem has been formulated with two parameters (the coefficient of restitution between particles, and the chute inclination), and three boundary values at the chute base wall, namely the values of solid fraction, granular temperature, and mean velocity at the wall. The boundary value problem has been numerically solved by the "shooting method." The results show the significant role played by granular conduction in determining the rpofiles of granular temperature, solid fraction, and mean velocity in chute flows. These analytical results are also compared with experimental measurements of velocity fluctuation, solid fraction, and mean velocity made by Ahn et al. (1989), and with the computer simulations by Campbell and Brennen (1985b)
Extended Axion Dark Matter Search Using the CAPP18T Haloscope
We report an extended search for the axion dark matter using the CAPP18T
haloscope. The CAPP18T experiment adopts innovative technologies of a
high-temperature superconducting magnet and a Josephson parametric converter.
The CAPP18T detector was reconstructed after an unexpected incident of the
high-temperature superconducting magnet quenching. The system reconstruction
includes rebuilding the magnet, improving the impedance matching in the
microwave chain, and mechanically readjusting the tuning rod to the cavity for
improved thermal contact. The total system noise temperature is 0.6\,K.
The coupling between the cavity and the strong antenna is maintained at to enhance the axion search scanning speed. The scan frequency range
is from 4.8077 to 4.8181 GHz. No significant indication of the axion dark
matter signature is observed. The results set the best upper bound of the
axion-photon-photon coupling () in the mass ranges of 19.883
to 19.926\,eV at 0.7 or
1.9 with 90\,\% confidence
level. The results demonstrate that a reliable search of the high-mass dark
matter axions can be achieved beyond the benchmark models using the technology
adopted in CAPP18T.Comment: 7 pages and 4 figure
Measurements of Velocity, Velocity Fluctuation, Density, and Stresses in Chute Flows of Granular Materials
Classification methods for the development of genomic signatures from high-dimensional data
Personalized medicine is defined by the use of genomic signatures of patients to assign effective therapies. We present Classification by Ensembles from Random Partitions (CERP) for class prediction and apply CERP to genomic data on leukemia patients and to genomic data with several clinical variables on breast cancer patients. CERP performs consistently well compared to the other classification algorithms. The predictive accuracy can be improved by adding some relevant clinical/histopathological measurements to the genomic data
Axion Haloscope Using an 18 T High Temperature Superconducting Magnet
We report details on the axion dark matter search experiment that uses the
innovative technologies of a High-Temperature Superconducting (HTS) magnet and
a Josephson Parametric Converter (JPC). An 18 T HTS solenoid magnet is
developed for this experiment. The JPC is used as the first stage amplifier to
achieve a near quantum-limited low-noise condition. The first dark matter axion
search was performed with the 18 T axion haloscope. The scan frequency range is
from 4.7789 GHz to 4.8094 GHz (30.5 MHz range). No significant signal
consistent with Galactic dark matter axion is observed. Our results set the
best limit of the axion-photon-photon coupling () in the
axion mass range of 19.764 to 19.890 eV. Using the Bayesian method, the
upper bounds of are set at
0.98
(1.11) in the mass ranges of 19.764 to
19.771 eV (19.863 to 19.890 eV), and at 1.76
in the mass ranges of 19.772 to
19.863 eV with 90\% confidence level, respectively. We report design,
construction, operation, and data analysis of the 18 T axion haloscope
experiment.Comment: PRD published versio
A Constructively Critical Conversation between Nonviolent and Substitutionary Perspectives on Atonement: Theological Motifs and Christological Implications
This dissertation will pursue a constructively critical conversation between nonviolent and substitutionary perspectives on atonement, for the purpose of reflecting theological motifs and Christological implications. I will critically engage Rita Nakashima Brock, Raymund Schwager, and J. Denny Weaver’s nonviolent approaches with the substitutionary doctrines of St Anselm, John Calvin, and Karl Barth. I conclude that theological reflection on the atonement is rendered problematic when any specific motif is absolutized, thereby opening the door to ideological projection of human needs. This holds true for theories that emphasize the nonviolent character of atonement as much as for any other model. In this thesis, I develop a holistic theology of atonement that critically incorporates elements of both traditional substitutionary theories, with their emphasis on the reconciliation between God and sinful humankind, and contemporary nonviolent theories, with their emphasis on the disclosure of structural evil by Jesus’ life and death. These dimensions of atonement are inseparable from the person of Christ, understood in Chalcedonian terms as both the eternal Son of God and the human Jesus of Nazareth. I will demonstrate that the nonviolent models’ emphasis on Jesus’ victimization by structural evils can co-exist with his sacrificial death, insofar as he takes sin, evil, and divine judgment into his own divine-human person. God’s disclosure of his solidarity with victims is inseparable from his act of actually liberating them from the violent powers of this world and reconciling them to himself.Doctor of Philosophy (PhD
Experimental and Analytical Investigations of Granular Materials: Shear Flow and Convective Heat Transfer
Granular materials flowing down an inclined chute were studied experimentally and analytically. Characteristics of convective heat transfer to granular flows were also investigated experimentally and numerically.
Experiments on continuous, steady flows of granular materials in an inclined chute were conducted with the objectives of understanding the characteristics of chute flows and of acquiring information on the rheological behavior of granular material flow. Two neighboring fibre optic displacement probes were employed to measure mean velocity, one component of velocity fluctuations, and linear concentration at the wall and free surface boundaries. A shear gauge was also developed to make direct measurement of shear stress at the chute base. Measurements of solid fraction, velocity, shear rate, and velocity fluctuations were analyzed to understand the chute flow characteristics, and the rheological behavior of granular materials was studied with the present experimental data. The vertical profiles of mean velocity, velocity fluctuation, and solid fraction were also obtained at the sidewalls.
Existing constitutive equations and governing equations were used to solve for fully developed chute flows of granular materials, and thus the boundary value problem was formulated with two parameters (the coefficient of restitution between particles, and the chute inclination) and three boundary values at the chute base wall (the values of solid fraction, granular temperature, and mean velocity at the wall). The boundary value problem was numerically solved by the "shooting method." The boundary conditions at the free surface were satisfied by the proper choice of a gradient of granular temperature at the wall. The results show a significant role played by granular conduction in determining the profiles of granular temperature, solid fraction, and mean velocity in chute flows. These analytical results were also compared with the present experimental measurements and with the computer simulations by other investigators in the literature.
Experiments on heat transfer to granular flows over a flat heating plate were conducted with three sizes of glass beads, polystyrene beads, and mustard seeds. A modification on the existing model for the convective heat transfer was made using the effective Nusselt number and the effective Peclet number, which include the effects of solid fraction variations. The slightly modified model could describe the heat transfer characteristics of both fast and slow flows (supercritical and subcritical flows).
A numerical analysis of the convective heat transfer to granular flows was also performed. The results were compared with the present experimental data, and reasonable agreement was found in the comparison.</p
Experimental investigation on flows in a corrugated channel
Flows in a corrugated channel are investigated by a high-speed camera and a particle image velocimetry (PIV) system. The bottom wall of the rectangular channel was corrugated with periodic grooves while the top wall and two sidewalls were flat plates made of Plexiglas. Flow visualization data from the high-speed camera determine the critical Reynolds number to be around 1500 by examining the stability of the vortex in the groove as well as fluid ejection from the groove. The visualization data for turbulent flow also show how a vortex evolves within the groove and triggers another vortex formation in the subsequent groove, and how fluid ejected from the groove triggers another ejection from the subsequent groove. Thus, strong hydrodynamic interactions are observed between successive corrugations. In addition, PIV data provide the profiles of velocities and Reynolds stresses as a function of Reynolds number. Time-averaged streamlines show that a large, stable vortex exists in the groove for laminar flow. On the other hand, for turbulent flow, the vortex is unstable inside the groove, often prompting fluid ejection which interacts with the bulk flow. Especially the Reynolds stress of the square of velocity fluctuation in the direction normal to the bulk flow significantly increases as the fluid ejection from the groove intensifies with increasing Reynolds number