| The Thermal Aspects of the Wear of Plastic Materials under Very High Contact Pressure and Sliding Velocity. |
05 JAN 1976 |
|
| Authors:
Yu Chen; RUTGERS - THE STATE UNIV NEW BRUNSWICK N J DEPT OF MECHANICS AND MATERIALS SCIENCE
|
 | A mathematical model depicting the heat conduction in the rotating band of a projectile and the gun is formulated. A solid inner cylinder in contact with a hollow outer cylinder, both infinitely long, are used to represent the gun tube and the rotating band. The frictional heat flux is imparted to these cylinders at an initial instant and the temperatures in each cylinder are analyzed. The boundary value problem is ... |
|
| Post-Engraving Stress Analysis of a Plastic Rotating Band. |
APR 1977 |
|
| Authors:
Yu Chen; LARGE CALIBER WEAPON SYSTEMS LAB (ARMY) DOVER N J
|
| Certain simplifying assumptions are made in order to calculate the stress history induced in a plastic rotating band as a result of its internal ballistic flight. (Author) |
|
| Acoustic Scattering by Near-Surface Inhomogeneities in Porous Media |
21 FEB 90 |
252 pages |
| Authors:
Keith Attenborough; David L. Berry; Yu Chen; OPEN UNIV MILTON KEYNES (UNITED KINGDOM) FACULTY OF TECHNOLOGY
|
 | A theoretical and experimental investigation into the influence of near-surface buried inhomogeneities on the reflection of air-borne acoustic fields at a porous ground surface has been conducted based on the assumption that the ground supports only one wave type. Two theoretical treatments of this problem are presented, both involving reformulations of initial boundary value problems as boundary integral equations. Predictions of these formulations are compared with each other and with ... |
|
| On the Inverse Scattering Problem for the Helmholtz Equation in One Dimension |
22 JUN 92 |
79 pages |
| Authors:
Yu Chen; YALE UNIV NEW HAVEN CT DEPT OF COMPUTER SCIENCE
|
| Interest in the numerical solution of acoustic inverse scattering problems arises in a number of areas. Examples include medical diagnostics, non- destructive industrial, testing, geophysical prospecting for petroleum and minerals, and detection of earthquakes. The highly nonlinear and oscillatory nature of the problem is one of the major difficulties one encounters in the construction of effective inversion algorithms. Schemes based on global or local linearization methods, or nonlinear optimization techniques, ... |
|
| Research on a New Type of IF Steel by Analytical TEM |
93 |
|
| Authors:
Qianti Chen; Yu Chen; Pinhe Li; WUHAN IRON AND STEEL CO (CHINA) INST OF IRON AND STEEL*
|
| A new type of IF steel which contains 0.076 wt% Al, 0.035 wt% Cu and has atom ratio of (Ti + Nb) to (C + N) approaching 1 was analyzed by TEM; the experimental results show that the second phase particles of TiCN, NbCN, AlN, epsilon-Cu or their complex precipitated during recrystallization have a strong effect of increasing the r-value (the average plastic strain ratio) which is an important parameter ... |
|
| Inverse Scattering via Heisenberg's Uncertainty Principle |
FEB 96 |
53 pages |
| Authors:
Yu Chen; YALE UNIV NEW HAVEN CT DEPT OF COMPUTER SCIENCE
|
| We present a stable method to recursively linearize the acoustic inverse scattering problem. It turns out that the ill posedness of the problem can be beneficially used to solve it. It means that, due to ill-posedness, not all equations in the nonlinear system are strongly nonlinear, and that when solved recursively in a proper order, they can be reduced to a collection of linear problems. Our method requires solution of ... |
|
| Inverse Scattering via Skin Effect |
MAY 96 |
35 pages |
| Authors:
Yu Chen; YALE UNIV NEW HAVEN CT DEPT OF COMPUTER SCIENCE
|
| We present a stable method for the inverse scattering problem of the Helmholtz equation in two dimensions. The algorithm requires single-frequency scattering data, and is an iterative procedure which resembles the process of layer-stripping. The inversion method is based on the observation that the ill- posedness of the inverse scattering problem causes it to be almost linear in certain regimes. In these regimes, the algorithm solves the resulting quasi- linear ... |
|
| Numerical Solution of Inverse Scattering Problems |
22 JUL 1998 |
7 pages |
| Authors:
Yu Chen; NEW YORK UNIV NY COURANT INST OF MATHEMATICAL SCIENCES
|
| The main activity of the research has been in the following two areas: to make the back propagation stable, and to design a frequency-local but space-global algorithm for one-dimensional inverse scattering problems. These two projects are being completed. The first one is an joint effort with V. Rokhlin whereas the second with Mr. Y. Xiang, a graduate student at the Courant Institute, currently support by the ONR grant during the ... |
|
| Fluorescent Heterogeneities in Turbid Media: Limits for Detection With Dual-Interfering Sources Excitation |
25 OCT 2001 |
|
| Authors:
X. Intes; Yu Chen; Xingde Li; B. Chance; PENNSYLVANIA UNIV PHILADELPHIA DEPT OFBIOENGINEERING
|
| A quantitative comparison between the single source and the dual- interfering sources configurations for the detection of fluorescent heterogeneities embedded in a piecewise highly scattering homogeneous fluorescent background was carried out. The study is based upon simulations using analytical solutions of the frequency domain diffuse photon density waves and practical signal-to-noise ratio considerations. Results show that the dual- interfering sources outperformed single source techniques for the detection of heterogeneities in ... |
|
Reports by Author
