Controlling the Intrinsic Josephson Junction Number in a Bi2Sr2CaCu2O8+δ\mathbf{Bi_2Sr_2CaCu_2O_{8+\delta}} Mesa

In fabricating $\mathrm{Bi_2Sr_2CaCu_2O_{8+\delta}}$ intrinsic Josephson junctions in 4-terminal mesa structures, we modify the conventional fabrication process by markedly reducing the etching rates of argon ion milling. As a result, the junction number in a stack can be controlled quite satisfactorily as long as we carefully adjust those factors such as the etching time and the thickness of the evaporated layers. The error in the junction number is within $\pm 1$. By additional ion etching if necessary, we can controllably decrease the junction number to a rather small value, and even a single intrinsic Josephson junction can be produced.Comment: to bu published in Jpn. J. Appl. Phys., 43(7A) 200

Sintering of Fine Oxide Powders: II, Sintering Mechanisms

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65619/1/j.1151-2916.1997.tb02879.x.pd

Reactive Cerium(IV) Oxide Powders by the Homogeneous Precipitation Method

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66445/1/j.1151-2916.1993.tb03942.x.pd

A ROBUST MODEL FOR ESTIMATING FREEWAY DYNAMIC ORIGIN-DESTINATION MATRICES

The purpose of this study is to develop an effective model and algorithm for estimating dynamic Origin-Destination demands for freeways. The primary challenge for this research subject lies in the fact that the number of unknown parameters is always more than the number of observable data, especially for a large network. Hence, the estimated O-D patterns may result in a large variance and insufficient reliability for use in practice. Besides, most existing approaches are grounded on the assumptions that a reliable initial O-D set is available and traffic volume data from detectors are accurate. However, in most highway network systems, both types of critical information are either unavailable or subjected to a significant level of measurement errors. To deal with those critical issues, this study has developed a set of dynamic models and solution algorithms for estimating freeway dynamic O-D matrices. The first extended model formulations can capture the speed discrepancy among drivers with an embedded travel time distribution function and the derivable interrelations between time-varying ramp and mainline flows. These formulations also feature their best use of the available mainline information and travel time function, and hence substantially increase the system observability with fewer parameters. The second component is an iterative algorithm that can be used to provide a reliable estimate of the initial O-D set, which is often unavailable in practice. The proposed algorithm first divides the network into small sub-networks to reduce the number of unknown variables, and recursively compute the O-D proportions for each sub-network to well capture the relations between the O-D demands and the input information. To deal with the constraints that the available data usually contain measurement errors, this research has developed an interval-based model for estimating dynamic freeway O-D demands. This component includes a set of formulations that converts each model input as an interval with its boundaries based on the prior knowledge. This study has performed sensitivity analyses and explored their potential for real-world application with the I-95 freeway corridor in Maryland. The numerical results under various traffic scenarios have indicated the promising properties of the proposed models and algorithms

Limit Analysis On Seismic Stability Of Anisotropic And Nonhomogeneous Slopes With Anti-slide Piles

This study employs the limit analysis method to evaluate the seismic stability of anisotropic and nonhomogeneous slopes stabilized with anti-slide piles. The pseudo-static approach is used to simplify the earthquake load. The yield seismic acceleration factor is obtained from the optimization procedure and the results are verified with the published data. Then, the seismically unstable slope is reinforced with anti-slide piles, and the seismic stability of the reinforced slope is explored. The results show that the anisotropy and Non homogeneity of soils have significant effects on the stabilizing force required from the anti-slide piles and the optimal location of the pile is near the toe of the slope

A GA-Based Approach to Hide Sensitive High Utility Itemsets

A GA-based privacy preserving utility mining method is proposed to find appropriate transactions to be inserted into the database for hiding sensitive high utility itemsets. It maintains the low information loss while providing information to the data demanders and protects the high-risk information in the database. A flexible evaluation function with three factors is designed in the proposed approach to evaluate whether the processed transactions are required to be inserted. Three different weights are, respectively, assigned to the three factors according to users. Moreover, the downward closure property and the prelarge concept are adopted in the proposed approach to reduce the cost of rescanning database, thus speeding up the evaluation process of chromosomes